AnnaleSKinesiologiae UDK / UDC 796.01:612 | Annales Kinesiologiae 8, 2017, 2, pp. 65-146 | ISSN 2232-2620 AnnaleSKinesiologiae UDK / UDC 796.01:612 | Annales Kinesiologiae 8, 2017, 2, pp. 65-146 | ISSN 2232-2620 PUBLISHING HOUSE ANNALES ZRS KOPER Koper 2017 ISSN 2232-2620 UDK/UDC 796.01:612 Volume 8, Year 2017, Number 2 ISSN (online ed.) 2335-4240 Editor in Chief / Glavni in odgovorni urednik: Rado Pišot Guest Editor / Gostujoči urednik: Mitja Gerževič Editors / Uredniki: Peter Čerče, Petra Dolenc, Mitja Gerževič, Mihaela Jurdana, Katja Koren, Uroš Marušič, Cecil J. W. Meulenberg, Nina Mohorko, Armin Paravlič, Saša Pišot, Matej Plevnik, Boštjan Šimunič Editorial Board / Uredniški odbor: Guglielmo Antonutto (Ita), Jakob Bednarik (Slo), Gianni Biolo (Ita), Cornelius P. 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Quantity /Naklada: 250 copies per issue Financial support / Finančna podpora: The publishing of this journal is supported by the Slovenian Research Agency slovenian research agency Izdajo revije sofinancira Javna agencija za raziskovalno dejavnost Republike Slovenije. Journal abbriviation: Ann Kinesiol. Annales Kinesiologiae is an international journal published twice a year. A annual subscriptions (2 issues in English language) are available for 25 eur, and single issue is available for 15 eur. For students 20% discount applies upon presenting an international valid student ID. Subscription requests can be send to: annales.kinesiologiae@zrs-kp.si TABLE OF CONTENTS Mitja Gerževič:........................................................................................................ 65 Editorial Uvodnik Patricia K. Doyle-Baker, Leanne Mclean, Tak Fung:.......................................... 69 Female athlete triad - Probable but difficult to confirm in female ice hockey players Ženska športna triada - verjetna, a jo je pri hokejistkah težko dokazati Eleonora Capatti, Edoardo Dalla Nora, Angelina Passaro:................................ 93 Physical activity and exercise as a key factor in successful aging Gibalna aktivnost in vadba kot ključna faktorja pri uspešnem staranju Enrico Rejc, Alessio Del Torto, Stefano Lazzer:...................................................111 Benefits of aerobic exercise training with recommendations for healthy aging Pozitivni učinki aerobne vadbe s priporočili za zdravo staranje Mihaela Jurdana:....................................................................................................125 Exercise effects on muscle stem cells Učinek telesne aktivnosti na skletno-mišične staminalne celice REVIEWS AND REPORTS OCENE IN POROČILA Matej Kleva:............................................................................................................137 Mediterranean Health Centre Mediteranski center zdravja Guidelines for authors Navodila avtorjem 143 EDITORIAL Dear reader of the second issue of the scientific journal Annales Kinesiologiae Volume 8. We are pleased to present five new articles that address the broad interdisciplinary field of the anthropological branch of kinesiology, as well as the importance of human movement, as the main study subject of this scientific discipline; all of them throughout different life periods and in the light of promoting healthy development and active lifestyle in both childhood and third age period. The introductory article focuses on the study of the female athlete triad and the associated negative energy balance, ovulation disorder, and osteopenia or even osteoporosis. Doyle-Baker, Mclean and Fung thus present the positive and negative effects of the menstrual cycle on sports performance and, through an empirical study, they determine the presence of the female athlete triad among elite female ice hockey players. This phenomenon is probable among athletes who are subject to high energy demands, although the authors find it difficult to confirm. Let's mention at this point that the abstract of this study was presented at the 8th International Scientific Conference on Kinesiology in Opatija, Croatia, and now we are glad to publish it as a full text in the present issue of the Annales Kinesiologiae journal. Further on, there are three review articles from the field of physical activity and exercise in the third age that have been prepared under the framework of the PANGeA project - Physical Activity and Nutrition for Quality Aging funded by the Interreg cross-border cooperation program Slovenia - Italy 2007-2013. They are rounded up so that Capatti, Dalla Nora and Passaro first present the problems with age-related changes in body composition and metabolism, including sarcopenia, sarcopenic obesity and bone loss with a progressive decline in aerobic capacity, muscle mass and strength as the main risk factors for reducing the mobility of older people, especially when combined with associated chronic diseases. Then, through extensive literature review, they summarize some recommendations for physical activity, exercise and nutrition, which enable older adults to maintain the heart and lungs function, to increase cardiovascular fitness and endurance, as well as preserving muscle mass and strength, bone density and reducing the increment of fat. It turns out that in older adults, especially with a combination of strength and endurance training, and appropriate protein intake, we can act both preventively and curatively against sarcopenia, sarcopenic obesity, and metabolic syndrome. This is followed by a review by Rejc, Del Torto and Lazzer, which present exhaustively the effects of aging on maximal aerobic power, the effects of aerobic exercise in older adults. At the end the authors summarize current recommendations for aerobic exercise during the third age. In doing so, authors are also critical of the valid recommendations, as they draw attention to their too generic nature and give suggestions for improvements. The third part of the review papers then deals with the aspect of the impact of exercise on activation and the increase in the number (proliferation) of the skeletal muscles stem (satellite) cells, which facilitate the recovery of the "damaged" muscle tissue under various psycho-physiological loads and stimuli. Jurdana thus updates the view on the role of muscular satellite cells in regulating muscle mass in conjunction with the effectiveness of various training interventions in order to reduce the decline in muscle mass that may be present in all stages of life, and especially in old age. She notes that it is possible to stimulate the activation and proliferation of skeletal muscle satellite cells, through an appropriate diet, resistance and endurance exercise, thus improving skeletal muscle function and successfully combating against muscular atrophy and age-related sarcopenia. She emphasizes that more studies will be needed for further understanding of the role and impact of training variables on the activation of satellite cells in order to set optimal training stimuli for this purpose. The report from the opening of the Mediterranean Health Centre (MHC) of the Science and Research Centre Koper rounds this issue of the journal. The MHC represents an important link between kinesiological science and practice as well as the socio-cultural environment and geographical location in which it was established, since the healthy Mediterranean lifestyle (in particular its typical diet, simplicity of living, social inclusion and interactions of people in this area) is thus enhanced by a healthy active lifestyle, exercise and training, kinesiological diagnostics and therapies based on modern scientific knowledge. All this has now become accessible to all of us, irrespective of age, gender, health status or other differences that can occur among people. This is also one of the most effective ways of implementing the mission to man-oriented kine-siology, which has an increasingly important role and responsibility in modern society in ensuring a healthy and balanced development of an individual and the society from childhood to the late adulthood. Mitja Gerzevic, PhD Guest Editor UVODNIK Spoštovani bralec druge številke osmega letnika znanstvene revije Annales Kine-siologiae. Z veseljem vam predstavljamo novih pet prispevkov, ki široko interdisciplinarno področje antropološke veje kineziologije in pomen gibanja človeka, kot glavnega predmeta preučevanja te znanstvene discipline, obravnavajo preko različnih življenjskih obdobij v luči spodbujanja zdravega razvoja in aktivnega življenjskega sloga, tako v otroštvu kot v tretjem življenjskem obdobju. Uvodni prispevek je nekoliko ožje usmerjen, in sicer v proučevanje ženske športne triade ter s tem povezanim pomanjkanjem energije oz. negativno energijsko bilanco, motnjo ovulacije in osteopenijo ali celo osteoporozo. Doyle-Baker, Mclean in Fung tako predstavljajo pozitivne in negativne vplive menstrualnega cikla na športno uspešnost ter preko empirične študije ugotavljajo pojavnost ženske športne triade med vrhunskimi igralkami hokeja na ledu. Pojav je med športnicami, ki so podvržene visokim energijskim zahtevam sicer možen, vendar avtorji ugotavljajo, da ga je težko potrditi. Naj omenimo, da je bil izvleček te študije predstavljen na 8. Mednarodni znanstveni konferenci o kineziologiji v Opatiji na Hrvaškem in ga sedaj z veseljem v celoti objavljamo v pričujoči številki revije Annales Kinesiologiae. Sledijo trije pregledni članki s področja telesne oz. gibalne/športne aktivnosti in vadbe v tretjem življenjskem obdobju, ki so bili pripravljeni v okviru projekta PANGeA - Telesna aktivnost in prehrana za kakovostno staranje. Projekt je potekal v okviru programa čezmejnega sodelovanja Interreg Slovenija-Italija 2007-2013. Članki so zaokroženi tako, da Capatti, Dalla Nora in Passaro najprej predstavijo problematiko s staranjem povezanih sprememb v telesni sestavi in metabolizmu, vključujoč sarkope-nijo, sarkopenično debelost in upad kostne mase ter trend postopnega upada aerobnih funkcij, mišične mase in moči kot glavnih dejavnikov tveganja za zmanjšanje mobilnosti starejših oseb, še posebej v povezavi s pridruženimi kroničnimi obolenji. Nato preko obširnega pregleda literature podajo priporočila za telesno aktivnost, vadbo in prehrano, ki starejšim osebam omogočajo ohranjanje ustreznega delovanja srčne in dihalne funkcije, izboljšanje srčno-žilne pripravljenosti in vzdržljivosti, kakor tudi ohranjanje mišične mase in moči, kostne gostote ter zmanjšanje pridobivanja maščobne mase. Izkaže se, da lahko pri starejših osebah, predvsem s kombinacijo vadbe za moč in vzdržljivost ter ustreznim vnosom beljakovin, delujemo tako preventivno kot kurativno proti sarkopeniji, sarkopenični debelosti in metabolnemu sindromu. Temu sledi pregled Rejca, Del Torta in Lazzerja, ki izčrpno predstavi vplive staranja na največjo aerobno moč, učinke aerobne vadbe pri starejših osebah in povzame trenutno veljavna priporočila za aerobno vadbo za to življenjsko obdobje. Pri tem se avtorji kritično opredelijo do veljavnih priporočil, saj opozorijo na njihovo preveliko generičnost in podajo predloge za izboljšanje. Tretji izmed preglednih prispevkov obravnava vidik vpliva vadbe na aktivacijo in povečanje števila (proliferacijo) matičnih (satelitskih) celic skeletnih mišic, ki olajšajo obnovo »poškodovanega« mišičnega tkiva po različnih psihofizičnih obremenitvah. Jurdana tako posodobi pogled na vlogo mišičnih satelitskih celic pri uravnavanju mišične mase v povezavi z učinkovitostjo različnih vadbenih intervencij za zmanjšanje upada mišične mase, ki je lahko prisotno v vseh življenjskih obdobjih, predvsem pa v starosti. Ugotavlja, da je tudi v starosti, preko ustrezne prehrane in vadbe proti uporu (za moč in silovitost) ter vadbe za vzdržljivost, možno spodbuditi akti-vacijo in proliferacijo satelitskih celic skeletnih mišic, s tem izboljšati mišično funkcijo ter se tako uspešno boriti proti mišični atrofiji in starostno pogojeni sarkopeniji. Pri tem pa poudarja, da bo potrebnih več študij, ki bodo bolje osvetlile in pojasnile vlogo in vpliv vadbenih spremenljivk na aktivacijo satelitskih celic ter podale za ta namen najoptimalnejše vadbene dražljaje. S poročilom z otvoritve Mediteranskega centra zdravja (MCZ) Znanstvenoraziskovalnega središča Koper pa zaokrožujemo celoto tokratnega izvoda revije. MCZ predstavlja namreč pomembno vez med kineziološko znanostjo in prakso ter družbeno-kul-turnim okoljem in geografsko lego, v kateri deluje, saj zdrav sredozemski življenjski slog (predvsem zanj značilna prehrana, enostavnost bivanja ter socialna vključenost in interakcija ljudi na tem območju) nadgrajuje z zdravim aktivnim življenjskim slogom, vadbo in treningom ter kineziološko diagnostiko in terapijami, ki temeljijo na sodobnih znanstvenih dognanjih. Vse našteto je s tem centrom postalo dosegljivo prav vsem, ne glede na starost, spol, zdravstveno stanje ali druge razlike, ki se med ljudmi lahko pojavljajo. Prav to je eden od najučinkovitejših načinov udejanjanja poslanstva k človeku usmerjene kineziologije, ki ima v sodobni družbi vse pomembnejšo vlogo in odgovornost pri zagotavljanju zdravega in uravnoteženega razvoja posameznika in družbe od otroštva do starosti. dr. Mitja Gerževič, gostujoči urednik Original scientific article received: 2018-01-24 UDC: 796.966-055.2:612.662 FEMALE ATHLETE TRIAD - PROBABLE BUT DIFFICULT TO CONFIRM IN FEMALE ICE HOCKEY PLAYERS Patricia K. DOYLE-BAKER12, Leanne MCLEAN1, Tak FUNG3 1 University of Calgary, Faculty of Kinesiology, Human Performance Lab 2 University of Calgary, Faculty of Environmental Design 3 University of Calgary, Research Computing Services, Information Technologies Corresponding author: Patricia K. DOYLE-BAKER Human Performance Lab, Faculty of Kinesiology University of Calgary, Calgary, Alberta, Canada T2N1N4 Tel.: 011 403 2207034 Email: pdoyleba@ucalgary.ca ABSTRACT Female hockey players have high energy expenditure and may enter a negative energy balance (EB) without noticeable body composition changes. Menstrual cycle (MC) and luteal phase (LP) length, EB, and bone mineral density (BMD) were tracked over nine months (mean, SD (±) in 12 ice hockey players (HP; age 21.1 ± 3.4 yrs; height (HT) 165.9 ± 4.6 cm; weight (WT) 64.7 ± 8.1 kg; body fat percent (BF %) 2.8 ± 3.8 %) and 12 non-athlete controls (C; age 21.4 ± 2.8yrs; HT 169.5 ± 5.5 cm; WT65.4 ± 5.4 kg; BF % 20.0 ± 3.1 %). HP MC (35.8 ± 11.2 days) was longer than C (29.8 ± 4.3 days) and HP LP (10.1 ± 2.1 days) was also longer than C (9.6 ± 2.8 days). Anovulation occurred in 50.0 % of HP versus 39.2 % of C. No group BMD differences were observed in lumbar spine (p = 0.9), hip (p = 0.5), and radial (p = 0.7) sites. A negative EB was identified (HP = -1026.52 ± 450.1; C = -780.00 ± 310.19 kcal /day), yet no significant within-group differences in WT (HPp = 0.7; Cp = 0.8), BF % (HPp = 0.97; C p = 0.6), or fat free mass (HP p = 0.6; C p = 0.98) were found over the study duration. Rigorous hockey schedule likely contributed to 28 % completion of the Basal Body Temperature and MC recordings in HP compared to 70 % in C. Both groups entered a state of negative EB, but did not exhibit a BF % change associated with the Female Athlete Triad. Keywords: menstrual cycle, female ice hockey players, bone mineral density. Patricia K. DOYLE-BAKER, Leanne MCLEAN, Tak FUNG: FEMALE ATHLETE TRIAD - PROBABLE BUT DIFFICULT TO CONFIRM ..., 69-92 ŽENSKA ŠPORTNA TRIADA - VERJETNA, A JO JE PRI HOKEJISTKAH TEŽKO DOKAZATI IZVLEČEK Za hokejistke je značilna visoka poraba energije, ki lahko vodi do negativnega energijskega ravnovesja (EB) brez opaznih sprememb v telesni sestavi. V obdobju 9 mesecev smo spremljali menstrualni ciklus (MC) in dolžino lutealne faze (LP), EB in mineralno gostoto kosti (BMD) pri 12 hokejistkah (HP; starost 21,1 ± 3,4 let; telesna višina (HT) 165,9 ± 4,6 cm; telesna masa (WT) 64,7± 8,1 kg; %telesnih maščob (BF %) 22,8 ± 3,8 %) in pri 12 kontrolnih ne-športnikih (C; starost 21,4 ± 2,8 let; HT 169,5 ± 5,5 cm; WT 65,4 ± 5,4 kg, BF % 20,0 ± 3,1 %). Pri skupini HP je bil zabeležen daljši MC (35,8 ± 11,2 dni) kot pri C (29,8 ± 4,3 dni) in pri HP je bil LP prav tako daljši (10,1 ± 2,1 dni) kot pri C (9,6 ± 2,8 dni). Pri 50,0 % HP je prišlo do anovulacije, medtem ko pri C le pri 39,2 %. Nismo ugotovili razlik v BMD na lumbarnih vretencih (p=0,9), medenici (p=0,5) in koželjnici (p=0,5). V času izvajanja študije smo zaznali negativno EB (HP =-1026,52 ± 450,1 kcal / dan; C = -780,00 ± 310,19 kcal / dan), ne pa tudi pomembnih razlik znotraj skupine pri WT (HP p = 0,7; C p = 0,8), BF % (HP p = 0,97; C p = 0,6), ali pusti masi (HP p = 0,6; C p = 0,98). Strog urnik hokejistkje najbrž razlog za zgolj 28 % popolnost njihovih zapisov bazalne temperature in MC, za razliko od 70 % poročanja pri C. Obe skupini sta dosegli negativno EB, ni pa bila vidna sprememba BF % v povezavi z žensko športno triado. Ključne besede: menstruacijski ciklus, hokejistke, mineralna gostota kosti INTRODUCTION There has been a dramatic increase in female athletic participation and intense physical activity (PA) in the past 30 years (Chen & Bryzyski, 1999; Highet, 1989; Nattiv, Agostini, Drinkwater, & Yeager, 1994; Prior, Vigna, & McKay, 1992). A growing concern among health care clinicians and practitioners is the potential detrimental effect of long term training on bone mineral density (BMD), which may be preceded by low energy availability (EA) (Olympic Charter, 2011). EA is defined as energy obtained through oral nutrition minus energy expended during exercise. It is reasonable to conclude that low energy may result because of increased energy expenditure (EE), decreased oral intake (either intentional or unintentional), or both (Kishner, 2016). Subsequently, musculoskeletal and reproductive dysfunction from this prolonged energy deficit may occur, inducing the amenorrhoeic condition (International Olympic Committee, 2005; Mountjoy et al., 2014; Nattiv et al., 1994; Otis, Drinkwater, Johnson, & Wilmore, 1997). BMD decreases with the number of missed menstrual cycles (MC) accumulated over months and years. More specifically, a regular MC with either anovu- Patricia K. DOYLE-BAKER, Leanne MCLEAN, Tak FUNG: FEMALE ATHLETE TRIAD - PROBABLE BUT DIFFICULT TO CONFIRM ..., 69-92 lation (absence of ovulation) or short luteal phase length (SLP) may pose also a risk for bone remodeling, imbalance and bone loss (Seifert-Klauss & Prior 2010). The Female Athlete Triad (Triad) and/or its individual components (decreased EA, menstrual dysfunction, and low BMD) have previously been identified in athletic women (Egan, Reilly, Whyte, Giacomoni, & Cable, 2003; Koehler, Achtzehn, Braun, Mester, & Schaenzer, 2013; Reed, De Souza, & Williams, 2013). All female athletes in any sport regardless of the competition level are at potential risk to develop the Triad. However, those females participating in endurance sports, such as track and field, swimming, and rowing, or in those events requiring subjective judging, such as gymnastics and figure skating, are most at risk (Martinsen & Sundgot-Borgen, 2013). The current risk profile of the Triad includes very little information on female athletes having 'average body weights and lean body mass' (LBM), who participate in predominantly team oriented, weight-bearing sports (e.g. ice hockey, field hockey, soccer, basketball, and volleyball). Female athletes in weight bearing sports may also be energy deficit without knowing it and have ovulatory disturbances leading to future bone loss (osteoporosis) or bone weakening (osteopenia). The sport of ice hockey requires a long-term commitment to skill development and physical fitness which may impact a player's EE levels. It is possible that over time players may enter a state of negative EB without noticeable body weight change. The prevalence of inadvertent low EA is unknown in female ice hockey players. Therefore, the primary purpose of this study was to describe menstrual disturbances using basal body temperature (BBT) analysis to determine luteal phase (LP) length, and occurrence of anovulatory cycles in a group of female ice hockey players (HP) (17-25 years of age) participating in the Olympic Oval High Performance Training Program (HPTP). Our control (C) group were non-athlete students recruited from the University of Calgary Community. We hypothesized that HP would: (Ho^ exhibit longer MC, shortened LP (<10 days), with a greater number of anovulatory cycles as indicated by the MC Diary and BBT measurements when compared with C; (Ho2) be in a state of negative EB in the absence of any change in body composition; and (Ho3) have greater baseline BMD values at the spine, hip, and radial site compared to C and the population reference standards. METHODS Our study took place over 9-months and encompassed the fall and winter university semesters (October to June). Recruitment occurred at the start of the fall semester (September 1999) and the data collection period had a staggered study start; October for HP and November for C. The staggered start was necessary because of scheduling issues and conflicts with booking the Dual Energy X-ray Absorptiometry (DXA) machine. Volunteers were invited to participate:1) if HP had a five-year history of hockey specific training and if they committed to four or more 75 minute training sessions per week at the Olympic Oval in Calgary, Alberta, 2) following completion of the Patricia K. DOYLE-BAKER, Leanne MCLEAN, Tak FUNG: FEMALE ATHLETE TRIAD - PROBABLE BUT DIFFICULT TO CONFIRM ..., 69-92 Baecke Questionnaire of Habitual Physical Activity (Baecke, Burema & Frijters, 1982), used to evaluate their physical activity level, and 3) following completion of the Eating Disorder Inventory (EDI-2) questionnaire and screening tool (EDI-SC) to identify predisposition towards disordered eating (Garner, 1991). Volunteers were excluded if they: (1) had used oral contraceptives during the preceding six months, (2) were smokers, (3) showed predispositions to disordered eating tendencies based on the EDI-2 and EDI-SC results, or (4) were involved in shift work (e.g. night shifts) as this would interfere with the accuracy of BBT methods (Prior, Vigna, Schulzer, Hall, & Bonen, 1990). Of the 38 volunteers, 4 HP and 5 C were excluded due to their use of oral contraceptives, and one HP scored positively for disordered eating tendencies and was referred to counseling. Data Collection Procedures and Measurement Participants attended a 2-hour information / education session during their study start week where demographic information, menstrual history and current menstrual status data were collected. A registered dietician provided education on how to correctly complete the 7-day dietary record including accurate recording of dietary intake, serving sizes, calories per serving, and how to read food labels and recall techniques. The participants were given similar detailed information on how to correctly complete the 7-day Activity Record, MC diary, and BBT measurements. During the study, multiple reminders (e.g. follow-up telephone contacts and emails) and assurances of confidentiality were incorporated into the data collection methods to increase response rate and decrease non-sampling errors (Ransdell, 1996). Menstrual Cycle Length MC was tracked on a calendar and participants were asked to identify the first day with a phone call to the research coordinator (RC). MC start was defined as the first day of menstrual flow and the final day was defined as the day before the onset of the next menstrual flow. MC length was calculated as the difference between the day before the onset of menstrual flow and the first day of the previous cycle and was calculated as the mean length of each recorded cycle from month 1 through to month 6 of the data collection period. Basal Body Temperature Participants were instructed to measure their oral BBT immediately upon waking and before standing using a low-reading digital thermometer read to the nearest 0.05°C. These measurements were recorded in the MC diary and in addition participants re- Patricia K. DOYLE-BAKER, Leanne MCLEAN, Tak FUNG: FEMALE ATHLETE TRIAD - PROBABLE BUT DIFFICULT TO CONFIRM ..., 69-92 corded their subjective observations about late rising, illness, amount of menstrual flow, emotions, and disturbed sleep. Participants also commented on subjective markers of ovulation such as mucous secretion and breast tenderness (Prior et al., 1990; Prior, 1996). Luteal Phase Length We chose the mean temperature method (MTM) to predict the onset of LP using pre-established criteria from Vollman (1977). According to Prior et al., (1990) the LP length determined by MTM is comparable to directly measured serum mid-cycle luteinizing hormone (LH) on the peak day (r = 0.891). The temperatures of a given MC were averaged and a corresponding mean line drawn across the graph of the data. The start of the LP was defined as the first temperature to rise above the mean line and remain above for three consecutive days. The end of the LP was defined as the day before the onset of the next menstrual flow (Prior et al., 1990). Temperatures of more than 0.5°C above the mean were discarded as febrile values (Vollman, 1977). SLP was defined as those cycles having LP length < 10 days within a cycle of normal length (Prior et al., 1990). Anovulation can be determined by a lack of thermal shift in BBT (Vollman, 1977). We designated anovulatory MCs as those cycles having irregular temperature patterns and the absence of a definite LP when a normal MC length of 21 to 36 days was maintained (Personal Communication, J. C. Prior, October 1999). The number of anovulatory cycles was expressed as a percentage of the total number of eligible cycles recorded for the study period. Total Energy Expenditure (TEE) EE includes the components of resting energy expenditure (REE), the thermic effect of food (TEF) and the energy expended through PA (EPA). REE is the largest single source of EE and accounts for approximately 50 to 75 % of an individual's TEE (Ma-han & Escott-Stump, 1996; Van Zant, 1992). TEE is defined as the energy expended due to resting physiological functions (e.g. ventilation, cardiovascular activity, protein, glycogen, and triglyceride synthesis, and electrical activity within the cells) (Thompson & Manore, 1996). We employed the Cunningham equation (1980) because of the ability to include fat free mass (FFM) in the calculation for estimated REE: (kcal / day) = 500 + 22 (FFM) (McArdle, Katch, & Katch, 1991). Thompson and Manore (1996) compared this equation against directly measured REE and to several predictive REE equations. The REE estimate derived from the Cunningham equation was the only estimate that was not significantly different than the directly measured REE in a study of 24 male and 13 female endurance athletes. Patricia K. DOYLE-BAKER, Leanne MCLEAN, Tak FUNG: FEMALE ATHLETE TRIAD - PROBABLE BUT DIFFICULT TO CONFIRM ..., 69-92 TEE was determined using estimated REE plus EPA and TEF (7 % of REE + EAP) (Personal Communication, K.A. Carter-Erdman, January 2000; Mahan & Escott-Stump, 1996). An estimate of the EPA was derived using the participants' 7-day Activity Records from three time points over the study collection period (October to June). Time 1 for the 7-day Activity Record started on the first day of menstrual flow during the month of October for HP and November for C. Records two and three were collected in similar fashion at two-month intervals. Participants were given instruction on recording daily activity into four 6-hour periods which included: (1) a general description of the activity (e.g. reclining, sitting, standing, walking, running, skating etc.); (2) an estimation of the effort involved (e.g. light, moderate, or vigorous effort); (3) a specific description of the activity performed (e.g. sitting-reading, standing-talking, walking to school etc.); (4) duration in minutes performing each activity; and (5) a check mark designating those activities that were sport-specific. Sport-specific activity was defined in this study as the performance of hockey related training. Verbal instructions with working examples were given regarding the accurate measurement and recording of activity type, intensity, duration and exercising radial pulse counts. The mean heart rate (HR) during exercise was calculated using HR taken at time 1, 2, and 3 as indicated on the Activity Records. Participants were also asked to record their weight each Monday during the study period. Each Activity Record was collected and evaluated at the end of the 7-day period and illegible and/or questionable entries were confirmed via telephone contact or personal interview. The accuracy of using Activity Records to estimate TEE is variable, with errors of various methods ranging from 6 to 30 % of actual energy need (Campbell, 1999). To establish the accuracy of several commonly employed methods of determining activity level, Miller, Freedson, and Kline (1994) tested five recording questionnaires against direct measurement of PA using a Caltrac accelerometer. The 7-day PA recall and the Caltrac were the only method that resulted in a significant Spearman rank order correlation coefficient (r = 0.79). EPA was also estimated based on each groups' habitual physical activity patterns and calculated as a percentage of REE: EPA = 75 % of REE for HP and 45 % of REE for C (Heyward, 1997; Mahalko & Johnson, 1980). This method is based on the factorial approach to calculating energy requirements of individuals (World Health Organization, 1985). Energy Intake EI was collected at the onset of the first day of menstrual flow from the 7-day dietary record. Diet records, three in total, were also collected at two-month intervals simultaneously with the collection of the 7-day Activity Records. To avoid recall bias, participants were instructed to record dietary intake within 30 minutes of ingestion and they were contacted via phone (RC) to fact-check their intake. A nutrition intern categorized data for entry into "Nutritionist 5.0 - version 1.6" software package (First Patricia K. DOYLE-BAKER, Leanne MCLEAN, Tak FUNG: FEMALE ATHLETE TRIAD - PROBABLE BUT DIFFICULT TO CONFIRM ..., 69-92 Data Bank, San Bruno, CA). Data were analysed to yield daily caloric intake, daily percentages for individual nutrients, and macro and micronutrient intakes. Energy Balance EB was calculated as the difference between the mean EI from the 7-day diet record and mean TEE calculated using REE, TEF, and EPA estimated by Heyward's (1997) approach, as stated above. Bone Mineral Density Baseline BMD testing of the lumbar spine (L1-L4), femoral neck, and distal radius occurred in week 1 for each group. DXA measurements were completed by a nuclear medicine technician (Hologic QDR2000- rectilinear scanner; Hologic, Inc.). Scan time was approximately 2 to 4 minutes and the coefficient of variation (CV) was better than 1.0 % for spinal measurements and approximately 2 to 3 % for femoral neck measurements (Hologic Manufacturers Inc., [On-line] August 1999; Personal Communication, Dr. R. Kloiber, April 2000). Individual BMD measurements in g/cm2 were compared to Hologic QDR 2000 reference standards of mean young adult BMD (T-score: standard deviation from the peak bone mass or young normal values of a female reference population) as well as across the groups (Kanis, Melton, Christiansen, Johnston & Khaltaev, 1994; Maggi, 1993). All reporting of the BMD values (BMD three decimal places; T-scores and Z-scores one decimal place) follow the Recommendations for Bone Mineral Density Reporting in Canada (Siminoski, et al., 2005). Body Composition A sport anthropometrist measured participant's height (HT), weight (WT), girths (10 sites), limb dimensions (8 sites), and skinfold thickness (15 sites) at start and end of the study, using a medical scale, Harpenden skinfold caliper, an anthropometer, and steel tape. The equations of Parizkova (1978) and Matiegka (1921) were used to estimate BF %, FFM (kg), and muscle mass percent (LMM %). Body composition in this study included: WT, BF, and FFM. Patricia K. DOYLE-BAKER, Leanne MCLEAN, Tak FUNG: FEMALE ATHLETE TRIAD - PROBABLE BUT DIFFICULT TO CONFIRM ..., 69-92 DATA ANALYSIS The main outcome was the identification of menstrual disturbances related to MC length (> 36 days oligomenorrhea vs < 21 days polymenorrhea), and SLP (< 10 days), as indicated by the MC diary and BBT measurements. The independent variables were: EI, TEE, EB, body composition, and BMD. Sample size Sample size was calculated from the results of a one-year prospective study investigating the proportion of menstrual disturbances in runners, as no available literature on female ice hockey players was found. Thirteen subjects (N = 66) were identified as experiencing menstrual disturbances based on their SLP (< 10 days) (Prior et al. 1990). Therefore, a conservative estimate of 20 participants was required to achieve a power of 80 % and an alpha of 0.05 for this study (Brant sample size calculator [On-line], August 1998). Statistics Statistical analyses were not performed because of the descriptive nature of the study; partly due to low compliance from HP. We report means (SD (±)) and box plots with median values, 25th and 75th percentiles, ranges, and outliers for percent change in WT, BF, FFM, BMD, T-Scores, Z-Scores, EI, TEE, EB, MC length and LP length. Percent change in WT, BF, and FFM were calculated to describe the pre (Tl)-post (T2) body composition change (Percent change = [(Time 2 - Time 1)/ Time 2]X100). RESULTS Three HPs were excluded because they did not provide MC diary data and one HP was excluded from the BMD analysis due to multiple missed appointments. Twelve hockey players (mean, SD (±): age = 21.1 ± 3.4 years; HT = 165.9 ± 4.6 cm; WT = 64.7 ± 8.1 kg; BF % 22.8 ± 3.8) and 12 non-athletes (age = 21.4 ± 2.8 years; HT = 169.5 ± 5.5 cm; WT = 65.4 ± 6.4 kg; BF % 20.0 ± 3.1) were enrolled in all testing sessions (n = 24). Anthropometric characteristics and exercise patterns for HP and C are listed in Table 1. No differences were observed between groups in anthropometric characteristics at the study start. The HP participated in l0.3 ± 4.1 as compared to the C 4.4 ± 1.8 number of exercise sessions per week. The calculated mean HR per exercise session was 151.1 ± 17.5 bpm and 137.2 ± 9.7 bpm in the HP and C, respectively. (see Table 1). Patricia K. DOYLE-BAKER, Leanne MCLEAN, Tak FUNG: FEMALE ATHLETE TRIAD - PROBABLE BUT DIFFICULT TO CONFIRM ..., 69-92 Table 1: Mean and standard deviations (SD (±)) of Hockey Player and Control group's anthropometric and exercise characteristics. Mean, SD Min Max HP (n = 12) Fat Free Mass (kg) 49.80 ± 5. l0 41.30 57.40 Muscle Mass (kg) 23.70 ± 4.30 16.70 31.80 Fat Mass (kg) 14.90 ± 3.90 10.50 21.60 Body Fat (%) 22.80 ± 3.80 17.00 29.20 Volume of thigh (cm3) 9217.90 ± 1336.70 7477.80 12130.20 Number of exercise / week 10.30 ± 4.10 5.00 21.00 Exercise duration / session (min.) 73.80 ± 14.90 60.00 90.00 Heart Rate / Session (bpm) 151.10 ± 17.50 125.00 175.00 C (n = 12) Fat Free Mass (kg) 52.20 ± 4.00 47.00 59.20 Muscle Mass (kg) 25.60 ± 3.10 21.40 32.90 Fat Mass (kg) 13.20 ± 3.10 8.50 18.80 Body Fat (%) 20.00 ± 3.10 14.90 25.40 Volume of thigh (cm3) 9185.90 ± 1011.20 7281.80 10392.80 Number of exercise / week 4.40 ± l.80 2.00 9.00 Exercise duration / session (min.) 56.70 ± 27.80 30.00 120.00 Heart Rate / Session (bpm) 137.18 ± 9.70 123.00 154.00 The median (25th and 75th percentile) WT percent change over the study duration for the HP and C was: -1.43 % (-2.45 % and 6.38 %) and 0.30 % (0.13 % and 2.53 %), respectively. The median (25th and 75th percentile) BF % percent change for the HP and C was: -4.42 % (-9.18 % and 0.34 %) and 4.73 % (-3.44 % and 9.28 %), respectively. No significant within group mean differences were observed for WT (HP p = 0.7; C p = 0.8), BF % (HP p = 0.97; C p = 0.6), and FFM (HP p = 0.6; C p = 0.98). Patricia K. DOYLE-BAKER, Leanne MCLEAN, Tak FUNG: FEMALE ATHLETE TRIAD - PROBABLE BUT DIFFICULT TO CONFIRM ..., 69-92 Bone Mineral Density Median values, 25th and 75th percentiles, ranges of the baseline BMD values (g / cm2) T-scores and Z-scores at the lumbar spine (L1-L4), total hip, and distal radius are presented in Table 2. Median lumbar spine and hip BMD were greater in the C (1.059 and 1.07 g / cm2) than in the HP (1.047 and 1.064 g / cm2). HP had one BMD measurement at the hip (1.357 g / cm2) that presented as an outlier (see Figure 1). There were no significant differences in mean lumbar spine, hip, or radial BMD values between the HP and C. However, the maximum value for all BMD measurement sites was greater in the HP. Median lumbar spine and hip T-scores were similar for HP and C. However median distal radius T-score was much larger for the HP (1.1) than C (0.5). The hip T-scores in the HP ranged from 0.1 to 3.4 as compared to a range of -0.9 to 2.6 in the C. The minimum lumbar spine (-0.7) and radial T-score (-0.9) in the HP and minimum T-score values at all sites in the C approached the WHO definition of osteopenia (-1.0 to -2.5). Figure 1 shows a comparison of HP and C T-scores values. Table 2: Bone mineral baseline values by site and group Median Percentile Range Median Percentile Range 25th 75th 25th 75th XI 1 , m Control Hocliey (n = 11) ^ = 12) Lumbar spine L1-L4 BMD g/cm2 1.047 0.993 1.149 0.968 -1.273 1.059 1.001 1.112 0.948 -1.251 T-Score 0.0 -0.5 0.1 -0.7 - 2.3 0.1 -0.4 0.7 -0.9 - 1.9 Z-score 0.2 -0.4 1.1 -0.5 - 2.4 0.2 -0.2 0.9 -0.9 - 2.1 Total hip BMD g/cm2 1.064 1.007 1.116 0.956 -1.357 1.07 0.982 1.12 0.838 -1.257 T-Score 1.0 0.5 1.8 0.1 - 3.4 1.0 0.3 1.5 -0.9 - 2.6 Z-score 1.1 0.5 2.6 0.1 - 3.4 1.2 0.5 1.4 -0.9 - 2.6 Distal radius BMD g/cm2 0.639 0.602 0.651 0.529 -0.691 0.606 0.602 0.651 0.545 -0.686 T-Score 1.1 0.4 1.3 -0.9 - 2.0 0.5 0.5 1.3 -0.6 - 1.9 Z-score 1.3 0.7 1.4 0.5 - 2.0 0.3 0.7 1.4 -0.5 - 1.9 Note: Outlier Total Hip HP 1.357 g/cm2 Patricia K. DOYLE-BAKER, Leanne MCLEAN, Tak FUNG: FEMALE ATHLETE TRIAD - PROBABLE BUT DIFFICULT TO CONFIRM ..., 69-92 Figure 1: Baseline BMD T-Scores at three sites for Control and Hockey Players. Energy Expenditure Table 3 lists the mean group values of EPA, REE, TEF and TEE for the HP and C. The mean HP-TEE was greater than C-TEE due to the varying contributions of EPA, TEF, and REE. EPA and TEF were greater in the HP than the C. The mean REE was greater for C. Values of EPA, REE, and TEF for both HP and C were verified to be within recommended theoretical percentages of TEE. The median EI (25th and 75th percentile) values for the HP and C were: 1880.3 (1714.6 and 2080.85) and 1799.2 (1509.1 and 2038.5) kcal / day, respectively (see Table 4). One HP had an average daily energy intake of 1065.6 kcal / day and was represented as an outlier. The median (25th and 75th percentile) TEE for the HP and C groups were 2854.2 (2802.8 and 3080.28) and 2544.01 (2440.08 and 2659.55) kcal / day respectively. The frequency distribution for HP-TEE is left skewed. Daily mean caloric intakes for the HP and C were 11 % (HP -1026.52 ± 450.1 kcal / day) and 15 Patricia K. DOYLE-BAKER, Leanne MCLEAN, Tak FUNG: FEMALE ATHLETE TRIAD - PROBABLE BUT DIFFICULT TO CONFIRM ..., 69-92 Table 3: Components of mean (SD (±)) Total Daily Energy Expenditure by group HP n = 12 C n = 12 kcal / day Mean, SD Min Max Mean, SD Min Max EPA 1116.48 ± 79.30 985.71 1234.42 741.75 ± 39.50 690.10 810.68 REE 1594.98 ± 113.30 1408.16 1763.46 1648.33 ± 87.80 1533.56 1801.52 TEF 189.80 ± 13.50 167.57 209.85 167.30 ± 8.90 155.66 182.85 TEE 2901.26 ± 206.10 2561.44 3207.73 2557.38 ± 136.1 2379.32 2795.06 Note: Estimated Energy of Physical Activity (EPA), Resting Energy Expenditure (REE), Thermic Effect of Food (TEF) and derived Total Daily Energy Expenditure (TEE) Table 4. HP and C Mean daily Energy Balance (calculated) Mean ± SD kcal / day hockey n = 12 Control n = 12 Daily Energy Intake 1882.89 ± 366.37 1777.3 l ± 328.62 Range 1065 to 2419 1212 to 2219 Total Energy Expenditure 2901.26 ±206.1 2557.38 ± 136.06 Mean Energy Balance -1018.37 ± 464.9 -780.07 ± 310.62 Note: Mean EB per day calculated as the difference between mean daily caloric intake (EI) and estimated total daily energy expenditure (TEE). % (C -780.00 ± 310.19 kcal / day) less than that recommended by Health and Welfare Canada (1990) for females aged 16 to 49 years (2100 kcal / day). There was a small difference of 105.5 kcal / day in daily EI between the HP and C but the number of exercise sessions per week and calculated mean HR per exercise session were also different. Thus, TEE between the HP and C was different and may have contributed to the difference in EB between the groups. Both groups maintained a state of negative EB for the study period as indicated by the mean TEE which exceeded daily caloric intake for both HP and C (see Table 4). The frequency distribution of HP-EB was symmetrical about the median and the median (25th and 75th percentile) was - 984.71 (- 1223.8 and - 767.7) kcal / day. The frequency distribution for C-EB Patricia K. DOYLE-BAKER, Leanne MCLEAN, Tak FUNG: FEMALE ATHLETE TRIAD - PROBABLE BUT DIFFICULT TO CONFIRM ..., 69-92 was right skewed and the median (25th and 75th percentile) was - 681.72 (- 1046.57 and - 595.25) kcal / day. Energy balance remained in a negative state despite corrections for errors (self-report corrected factor ~30 %) in estimating daily EI such that mean corrected EB for the HP and C was -641.8 and -424.6 kcal / day, respectively. Menstrual Cycle Characteristics Out of a possible 78 cycles for the HP and 72 cycles for the C, only 22 HP and 51 C cycles were included in the analysis due to incomplete data. The HP and C median (25th and 75th percentile) LP lengths were 9.0 (9 and 11) and 9.4 (8.3 and 10.5) days, respectively. Mean LP length for the C (9.4 ± l.9) was slightly less than the HP (9.9 ± 1 .7) days. Both groups were classified as having SLP ( 60 %), is generally associated to a lowering in total body fat (FM), even in the absence of changes in dietary regime, proportional to the amount of training sessions. In particular, aerobic exercise can induce significant results on the loss of adipose tissue in the abdominal region (VAT) (Kay & Fiatarone Singh, 2006). In order to estimate VO2max and fitness index, a two-km walking test was developed by the UKK Institute in Finland (Laukkanen, Oja, Ojala, Pasanen, & Vuori, 1992). This test, relatively simple to administer, is a feasible and accurate alternative for determination of cardio-respiratory fitness in adults with both normal body weight as well as in overweight individuals. In Ferrara's population of PANGeA study (a mass population study we conducted with Slovenian colleagues, aiming at identifying the main elements involved in successful aging), applying the UKK-test, we found that fitness index is inversely correlated to waist circumference. In this population, applying a linear regression model, fitness index, independently of gender and age, predicts waist circumference, explaining the 32 % of its variability (R2 square 0,322, standardized P-coefficient -0,477, p < 0,001) (Figure 1, data not published). PHYSICAL EXERCISE AND CHANGES IN BODY METABOLISM Even if not associated with a specific dietary regime, aerobic exercise and resistance training may be responsible for different and positive changes in body metabolism: - improvement in glycemic control (Sigal et al., 2007), due to increases in muscle GLUT4 number and function (Holten et al., 2004), - improvements in insulin sensitivity (Winnick et al., 2008), - stimulation of lipid oxidation, - improvement in lipid profile with increased clearance of atherogenic lipids, specially triglycerides (Katsanos, 2006), reduced levels of total cholesterol and apolipoprotein B (Holme, H0stmark, & Anderssen, 2007), changes in LDL par- Eleonora CAPATTI, Edoardo DALLA NORA, Angelina PASSARO: PHYSICAL ACTIVITY AND EXERCISE ..., 93-109 Figure 1. Pearson correlation between fitness index and waist circumference (PANGeA s Ferrarapopulation): Men r=-0,62, p< 0.001; Women r=-0,401, p=0,001. ticle size (more than lower levels) and higher HDL concentration (Kraus et al., 2002), - decrease of VAT in relation to an increased sympathetic tonus and consequential increased lipolysis (Ismail, Keating, Baker, & Johnson, 2012), - decrease of VAT and pro-inflammatory state may contribute to improve glucose uptake (Fisher et al., 2011), - decrease in biomarkers of inflammation like C-reactive protein (CRP) (Strasser, Arvandi, & Siebert, 2012), - improvement in adiponectin and leptin profile (Simpson & Singh, 2008). The impact of aerobic exercise on body metabolism is better and more significant if it is characterized by high intensity; strength training can provide up to a 15 % increase in metabolic rate, which is very helpful in terms of weight loss and long-term weight control. A review published by Strasser provides strong support for the recommendation that physical activity, in particular resistance training mixed with aerobic exercise, should be an integral component in the prevention and treatment of obesity and metabolic syndrome risk factors (Strasser, 2013). Resistance training is an effective way to increase energy requirements, decrease body FM, and maintain metabolically active Eleonora CAPATTI, Edoardo DALLA NORA, Angelina PASSARO: PHYSICAL ACTIVITY AND EXERCISE ..., 93-109 tissue mass. A consequent improvement in insulin sensitivity and in the lipid profile could reduce the risk of metabolic syndrome and type 2 diabetes and attenuate the development of cardiovascular disease in an elderly population (Ferrara, Goldberg, Ortmeyer, & Ryan, 2006). PHYSICAL ACTIVITY AND RELATED BENEFITS It is well established that with increasing age, individuals are more likely to experience functional declines, mobility limitations, and physical disability (Holmes, Powell-Griner, Lethbridge-Cejku, & Heyman, 2009). A large body of literature has supported the interrelationships among various factors affecting physical function (PF) in older adults (Villareal et al., 2011), like physical activity, body composition (fat mass and skeletal muscle mass), muscle capacity (leg strength and leg power), and muscle quality, whose aging-related changes tend to promote a decline in maximal aerobic power and skeletal muscle force production. Although the likelihood of physical limitations and disability increases with age, multiple studies have demonstrated that exercise is an effective intervention strategy for improving PF in older adults (Brady, Straight, & Evans, 2014). Several intervention trials have reported improvements in PF after a resistance training program in relatively healthy older (Avila, Gutierres, Sheehy, Lofgren, & Del-monico, 2010; Henwood & Taaffe, 2005), as well as older adults with chronic health conditions (Yang, Wang, Lin, Chu, & Chan, 2006). In addition, aerobic training, often a cornerstone of an exercise program, has also been found to be beneficial at improving PF in older adults (Davidson et al., 2009). The evidence suggests how the pillars of an effective exercise program should be both aerobic and resistance exercise (Chodzko-Zajko et al., 2009) and it is well known that both endurance exercise and resistance training can substantially improve physical fitness and health-related factors in older individuals (Conceigao et al., 2014). This helps to maintain and increase skeletal muscle mass and respiratory fitness, with increase in resting metabolic rate and enhanced capacity for lipid oxidation during rest and exercise. Endurance training in particular is purported to be more effective for decreasing FM, resting heart rate and blood pressure, while resistance training has been shown to be more effective for increasing basal metabolism, bone mineral density (BMD) and muscle strength and power (Romero-Arenas, Martínez-Pascual, et al. 2013). Regular physical activity can have a positive effect on disorders and diseases that affect muscles and bones (such as osteoarthritis, back pain and osteoporosis). Walking provides a modest increase in the loads on the skeleton above gravity and, therefore, this type of exercise has proved to be less effective in osteoporosis prevention. Strength exercises instead, seems to be a powerful stimulus to improve and maintain bone mass during the aging process (Gomez-Cabello, Ara, González-Agüero, Casajús, & Vicente-Rodríguez, 2012). Eleonora CAPATTI, Edoardo DALLA NORA, Angelina PASSARO: PHYSICAL ACTIVITY AND EXERCISE ..., 93-109 Many evidences show that physical activity programs aimed at strengthening muscles help the elderly to maintain balance, which decrease the likelihood and severity of falls and fractures, one of major health concerns for many older adults (Howe, Rochester, Neil, Skelton, & Ballinger, 2011). Compared to sedentary people, older athletes enjoy a wide range of physiological benefits on health: - a better profile in body composition including a lower accumulation of total and especially abdominal fat; greater volume muscle mass in upper and lower limbs, - higher bone mineral density (BMD), especially in case of strength training with high-load low repetitions (Romero-Arenas, Blazevich, et al., 2013), - articulation muscle more resistant to oxidative processes and fatigue, - a better cardiac output during maximum exercise and improved cardiovascular fitness (Gibala, Little, MacDonald, & Hawley, 2012), - less cardiovascular and metabolic stress during sub-maximal exercise (Lanza et al., 2008), - significantly reduced coronary risk profile in relation to lowering of blood pressure (Whelton, Chin, Xin, & He, 2002), improvement in endothelium function (Maiorana, O'Driscoll, Taylor, & Green, 2003); low systemic inflammatory index; improved insulin sensitivity and glucose homeostasis; better lipid profile and lower waist circumference, - slowed development of disability in old age. Twenty to forty minutes a day of aerobic training leads to a lower probability to develop metabolic and cardiovascular diseases. Moreover, several studies have shown the beneficial effects of circuit weight training in individuals with CHD. Volaklis et al. combined resistance circuit and aerobic exercise program in patients with coronary artery disease. Subjects improved cardiovascular fitness (VO2 peak 15.4 %) and muscular strength significantly in all exercises by an average of 28 % (Volaklis, Douda, Kokkinos, & Tokmakidis, 2006). A Cochrane review of 121 randomized controlled trials of progressive resistance training (PRT) in older people showed that doing PRT 2-3 times per week improved physical function, gait speed, timed get-up-and-go, climbing stairs, and balance, and, more importantly, had a significant effect on muscle strength, especially in the high-intensity training groups (Crocker et al., 2013). In order to optimize body composition, muscle strength gains and to develop cardiovascular function, Romero-Arenas, Martínez-Pascual, et al. (2013) recommended a circuit weight training with a minimum frequency of 2 sessions per week (with a volume ranging from 30 to 50 minutes) that could be implemented with endurance training. Eleonora CAPATTI, Edoardo DALLA NORA, Angelina PASSARO: PHYSICAL ACTIVITY AND EXERCISE ..., 93-109 DIET COMBINED WITH PHYSICAL ACTIVITY AND BODY COMPOSITION Aging is related with the loss of skeletal muscle and bone mass along with progressive increase of adipose tissue. Recent investigations have attempted to modify these processes with various combinations of dietary and exercise intervention (Iglay, Thy-fault, Apolzan, & Campbell, 2007; Kukuljan, Nowson, Sanders, & Daly, 2009). Increasing the quantity and quality (essential amino acids, specifically leucine) of dietary protein stimulates muscle protein synthesis in the elderly (B0rsheim et al., 2008), while protein supplementation at twice the Recommended Dietary Allowance (RDA) does not improve skeletal muscle function or increase muscle mass in healthy elderly weight lifters compared to those on a normal diet (Campbell & Leidy, 2007). Therefore, regular resistance exercises and the habitual ingestion of adequate amounts of dietary protein from high-quality sources are two important ways to slow the progression and treat sarcopenia. Assuming three meals are consumed each day, a relative protein dose of 0.4 - 0.5 g / kg / meal is consistent with recent expert opinions concerning the optimal daily protein intake (1.2 - 1.5 g / kg / day) for healthy older adults (Deutz et al., 2014). This amount of protein markedly exceeds the RDA for protein (at present set at 0.8 g / kg ideal body mass / day for healthy adults, regardless of sex and age), but it is supported by several larger-scale longitudinal studies (Bartali et al., 2012; Gray-Donald et al., 2014). Several studies have also reported a positive relationship between protein intake and peak bone mass in older adults (Hannan et al., 2000; Sahni et al., 2014). Increased intake of vitamin D stimulates gene expression and boosts muscle protein synthesis, facilitates neuromuscular function and enhances strength and balance (Muir & Montero-Odasso, 2011). In a recent clinical trial, Rondanelli et al. found a significant beneficial effect of supplementation with whey protein, essential amino acids, and vitamin D compared with placebo in elderly sarcopenic adults participating in controlled resistance training, with a gain of 1.7 kg in FFM. Supplementation attenuated the inflammatory state, as seen by the significant drops in CRP concentrations and leads to a reduced prevalence of malnutrition, assessed with the Mini Nutritional Assessment (MNA) (Rondanelli et al., 2016). In all individuals older than 70 years of age, vitamin D intakes of at least 600 IU per day (up to 1000 IU / day) are recommended, in addition to the calcium requirement of 1200 mg per day (American Geriatrics Society Workgroup on Vitamin D Supplementation for Older Adults, 2014). For those individuals in whom there is inadequate calcium and vitamin D intake from diet, supplements and/or multivitamins can be used. A recent review suggests that calcium and vitamin D supplementation, with or without osteoporosis therapy, may decrease the risk of fractures (Tricco et al., 2017). Anyway, the U.S. Preventive Services Task Force (USPSTF) concluded that the current evidence is insufficient to assess the balance of benefits and harms of combined vitamin D and calcium supplementation to prevent bone fractures in premenopausal women or in men (Moyer & U.S. Preventive Services Task Force*, 2013). Eleonora CAPATTI, Edoardo DALLA NORA, Angelina PASSARO: PHYSICAL ACTIVITY AND EXERCISE ..., 93-109 CONCLUSIONS An inevitable consequence of advancing age is the gradual loss of muscle mass and strength, termed sarcopenia, frequently associated with a parallel increase in fat mass. This geriatric condition has known negative impacts on metabolic health, and in later life, the ability to perform everyday activities (Witard, McGlory, Hamilton, & Phillips, 2016). This review highlights the major benefits of physical activity in the elderly in terms of body composition and metabolism. Active elderly subjects show a slower "aging clock" and a lighter burden of chronic morbidity. Aerobic exercises help to raise heart and lung efficiency and to increase cardiovascular fitness and endurance, while resistance training promotes an increase in muscle mass and bone density. Achieving these goals represents the first step of a realistic strategy for maintaining functional status and independence. International guideline recommendations suggest that older people should perform at least 150 minutes of moderate physical activity per week and should be less sedentary in order to achieve health benefits (World Health Organization, 2010). Active elderly in particular, seems to develop a "successful aging" compared to sedentary ones. Developing simple lifestyle interventions and safe, effective and sustainable ways to promote physical activity, aimed to preserve muscle mass and strength with advancing age, is crucial for the care of patients in mid-life and beyond. REFERENCES American Geriatrics Society Workgroup on Vitamin D Supplementation for Older Adults (2014). 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Nutrition, Metabolism and Cardiovascular Diseases, 18(5), 388-395. doi: 10.1016/j.numecd.2007.10.002 VIEW ITEM Review article received: 2017-06-16 UDC: 796.012:613.2 BENEFITS OF AEROBIC EXERCISE TRAINING WITH RECOMMENDATIONS FOR HEALTHY AGING Enrico REJC12, Alessio DEL TORTO13, Stefano LAZZER13 1 Department of Medicine, University of Udine, Italy. 2 University of Louisville, Department of Neurological Surgery, Louisville, USA. 3 School of Sport Sciences, University of Udine, Italy. Corresponding author: Prof. Stefano LAZZER University of Udine Department of Medicine P.le Kolbe 4 33100 Udine, Italy. Phone: +39 0432 494333 - Fax: +39 0432 494301 e-mail: stefano.lazzer@uniud.it ABSTRACT The purpose of this articlet is to provide an overview of the importance of aerobic exercise and its characteristics for healthy aging. The first section briefly reviews the effects of aging on maximal aerobic power; Section 2 considers the effects of aerobic exercise training, and Section 3 summarizes the recommendations and some limitations of the current guidelines for aerobic exercise training. Physical activity cannot stop the biological processes; however, there is evidence that regular aerobic exercise can minimize the physiological effects of an otherwise sedentary lifestyle and increase active life expectancy by limiting the development and progression of chronic disease and disability conditions. The use of moderately standardized guidelines for exercise prescription resulted in safe and effective impact on health-related outcomes. Keywords: aerobic exercise; physical activity; training. Enrico REJC, Alessio DEL TORTO, Stefano LAZZER: BENEFITS OF AEROBIC EXERCISE TRAINING WITH RECOMMENDATIONS ..., 111-124 POZITIVNI UČINKI AEROBNE VADBE S PRIPOROČILI ZA ZDRAVO STARANJE IZVLEČEK Namen tega članka je podati pregled razpoložljivih informacij o pomenu aerobne vadbe in njenih lastnosti za zdravo staranje. V prvem delu so na kratko predstavljeni učinki staranja na maksimalno aerobno moč. Drugi del obravnava učinke aerobne vadbe, medtem ko so v tretjem delu povzeta priporočila ter nekatere omejitve trenutno veljavnih smernic za aerobno vadbo. Telesna aktivnost ne more ustaviti bioloških procesov. Kljub temu pa je na voljo precej dokazov, da redna aerobna vadba zmanjšuje fiziološke učinke sicer sedentarnega življenjskega sloga ter obenem podaljšuje pričakovano življenjsko dobo s tem, ko omejuje nastanek in razvoj kroničnih bolezni ter pogojev invalidnosti. Uporaba zmernih standardiziranih smernic pri predpisovanju telesne vadbe, se odraža neposredno v varnih in učinkovitih vplivih na zdravje in z zdravjem povezana pričakovanja. Ključne besede: aerobna vadba, telesna aktivnost, vadba. INTRODUCTION The most widely used terms of maximal aerobic functional power are peak and maximum oxygen uptake (V'O2peak and V'O2max). Both terms are often used as though they are synonymous, but there are important distinctions to be made between them (Whipp, Davis, Torres, & Wasserman, 1981). While the V'O2peak is easier to define and determine, its relevance to physiological and patho-physiological functioning is less secure. It is, simply, the highest value of V'O2 attained on the particular test, most commonly an incremental or other high-intensity test designed to bring the subject to the limit of tolerance - neglecting considerations of what time, or breath-number, frame of reference is chosen for the determination. Unfortunately, it is the highest value achieved regardless of the subject's effort. And so while it defines the highest V'O2 that was attained during the test it does not necessarily define the highest value attainable by the subject. This value is the V'O2max: a term introduced by Hill and Lupton in 1923 (Hill & Lupton, 1923) as "the oxygen intake during an exercise intensity at which actual oxygen intake reaches a maximum beyond which no increase in effort can raise it"; its rigorous determination depends on a particular criterion having been met. Considering this, the demonstration V'O2 does not continue to increase, or only to increase by a trivially-small amount, despite further increases in work rate "involving a large proportion of muscle mass" i.e., a V'O2 "plateau" shows results when V'O2 is plotted as a function of work rate. Enrico REJC, Alessio DEL TORTO, Stefano LAZZER: BENEFITS OF AEROBIC EXERCISE TRAINING WITH RECOMMENDATIONS ..., 111-124 Cross-sectional studies show that V'O2peak typically declines 6 - 10 % per age decade in healthy men and women (Talbot, Metter, & Fleg, 2000; Wilson & Tanaka, 2000; Aspenes et al., 2011). However, the older individuals included in these studies conceivably presented favourable genetics as well as lifestyle differences, thus limiting the generalization of findings for their age peers. In a longitudinal study, a decline in peak V'O2 of 20 - 25 % per decade was shown in 70+ healthy elderly subjects (Fig. 1) (Fleg et al., 2005). Hawkins et al. (Hawkins, Marcell, Victoria Jaque, & Wiswell, 2001) also subdivided the sample of master athletes by age group and found that loss rates in maximal oxygen uptake (V'O2max) increased with age, from rates similar to those reported for sedentary subjects in the younger master athletes to rates four times greater than sedentary subjects in the older master athletes (Figure 1). The declines of 20 - 30 % per decade most likely reflect the periods of rapid decline associated with reductions in physical activity and exercise. These findings suggest that either accelerates the reduction in V'O2max or increases the difficulty of maintaining training. Decline in V'O2max can be attributed to age-related reductions in both maximal cardiac output (Q'max) and maximal arteriovenous oxygen (a-v O2) difference in sedentary subjects, while in older endurance-trained individuals only the reduction of Q'max might explain the age-induced decline in maximal aerobic power (Ogawa et al., 1992). Maximal heart rate decreases about six to ten beats per minute per decade, and is responsible for much of the age-associated decrease in Q'max (Hawkins et al., 2001). However, a reduction in stroke volume during maximal exercise in older adults also contributes to the decline in cardiac output (Hagberg et al., 1985). In addition, left ventricular ejection fraction appears to be reduced in older adults during maximal exercise compared to young adults (Taylor & Groeller, 2008; Thomas, Paterson, Cunningham, McLellan, & Kostuk, 1993). Decreases in vascular capacity and local blood flow regulation, along with a decline in muscle oxidative capacity contribute to the overall reduction in maximal a-v O2 difference observed with age (Sagiv, Goldhammer, Ben-Sira, & Amir, 2010; Toda, 2012). Coupled with poor oxygen delivery mechanisms, mitochondrial alterations also lead to a reduction in maximal capacity to utilize oxygen at the level of active skeletal muscle. For a submaximal exercise bout, cardiac output is lower in older adults, while a-v O2 difference may tend to increase as a compensatory response to maintain V'O2. A reduction in stroke volume appears to be the major factor responsible for the lower cardiac output observed during submaximal exercise (Ogawa et al., 1992). Blood pressure is also higher in absolute as well as relative work rates in older adults as compared to younger adults. In addition, total peripheral resistance is generally higher in older adults for a given exercise intensity (Ogawa et al., 1992). Although reduced physical activity with age contributes to decrease the maximal aerobic power, similar rates of decline are observed with age even among highly active individuals. However, the V'O2peak of such athletic persons is substantially higher than that of their age peers (Fleg et al., 1994). Moreover, the cardiovascular (CV) system remains fully adaptable to training at any age (Kohrt et al., 1991) with relative increases in V'O2max in adults of any age equivalent to those seen in young individuals. Given the effect of cardio vascular exercise training and greater fitness on CV disease Enrico REJC, Alessio DEL TORTO, Stefano LAZZER: BENEFITS OF AEROBIC EXERCISE TRAINING WITH RECOMMENDATIONS ..., 111-124 Figure 1: Cross-sectional versus longitudinal comparison of loss rates in maximal oxygen consumption (V'O2max) [mL/kg/min] in men and women master athletes (adapted from Hawkins & Wiswell, 2003). 40 45 50 55 60 65 Age (y) **: Significantly different rate of loss compared with cross-sectional. Enrico REJC, Alessio DEL TORTO, Stefano LAZZER: BENEFITS OF AEROBIC EXERCISE TRAINING WITH RECOMMENDATIONS ..., 111-124 risk factors (Kelley & Sharpe Kelley, 2001), mortality, and all-cause mortality (Myers et al., 2002), recommending aerobic activity to adults of all ages would seem prudent (Balady, 2002). EFFECTS OF AEROBIC EXERCISE TRAINING The ability to maintain high aerobic power is a major determinant of an older adult's functional independence. Several observational studies have demonstrated that endurance athletes, even those in their 60s and beyond, maintain a V'O2peak considerably higher than the one of less active age peers. For example, the V'O2peak in distance runners aged 60 - 80 years was 30 - 40 % higher than active non-trained age peers in the Baltimore Longitudinal Study of (BLSA). In fact, their aerobic capacity was similar to that of BLSA participants 2 or 3 decades younger (Fleg et al., 1994). As well, data from the Heritage Family Study suggest that genetics explains 47 % of the V'O2peak response to 20 weeks of aerobic exercise training after adjustment for age, sex, baseline V'O2peak, and baseline body mass and composition (Bouchard, 2012). Additionally, multiple studies have documented training-induced increases of 10 - 25 % in V'O2peak among adults in their 60s to 80s, and these increases are similar to those in younger adults (Vaitkevicius et al., 2002). A meta-analysis of training studies in persons aged 60 and older found a mean increase in V'O2peak of 16% (Huang, Gibson, Tran, & Osness, 2005). In general, higher intensity training and longer exercise duration elicited greater improvement. In addition to its beneficial effects on aerobic capacity, exercise training produces multiple benefits that reduce risk factors for CV disease. Hypertension Hypertension is defined by a systolic blood pressure (BP) >140 mmHg and / or diastolic BP >90 mmHg, and it represents the leading risk factor for global burden of disease and mortality (Roger et al., 2012). High blood pressure contributes to 7.0 % of disability-adjusted life-years and 9.4 million deaths. Also, the estimated number of adults with hypertension will be increased to 1.56 billion by 2025 (Hu et al., 2016). The prevalence of hypertension increases with age and it represents a risk factor for the most common causes of morbidity and mortality in older age such as stroke, ische-mic heart disease, heart failure and coronary events (Lloyd-Sherlock, Beard, Minicuci, Ebrahim, & Chatterji, 2014). In both younger and older persons with hypertension, regular aerobic exercise reduces BP. Important mechanisms contributing to exercise-related BP reduction include a decrease in aortic stiffness and enhanced flow-mediated arterial dilation due to increased nitric oxide release from endothelial cells lining these blood vessels (DeSouza et al., 2000). The reductions in BP from aerobic exercise are often similar to those induced Enrico REJC, Alessio DEL TORTO, Stefano LAZZER: BENEFITS OF AEROBIC EXERCISE TRAINING WITH RECOMMENDATIONS ..., 111-124 by a single antihypertensive drug. Mean BP reduction in a large meta-analysis averaged 3.8-2.6 mmHg (Whelton, Chin, Xin, & He, 2002). It is important to point out that lower intensity exercise equivalent to brisk walking demonstrated BP reductions similar to that of more intensive training in older hypertensive adults (Hagberg, Montain, Martin, & Ehsani, 1989). Dyslipidemia Abnormal blood lipids are powerful risk factors for CV events in older adults. Aerobic exercise training has beneficial effects on these abnormal lipid levels, irrespective of age. In a meta-analysis of aerobic exercise training trials in older adults, significant increases in high density lipoprotein (HDL) or "good" cholesterol averaged 2.5 mg/ dl, and reduced total cholesterol / HDL cholesterol ratio were observed, independent of changes in body composition; improvements in blood lipids correlated with increases in V'O2peak (Kelley, Kelley, & Tran, 2005). Weight loss, which is often observed during prolonged training programs, may further improve lipid profile (Katzel et al., 1995). Glucose Tolerance Aging is accompanied by reduced insulin sensitivity, which impairs glucose tolerance. This adaptation often results in type 2 diabetes mellitus, which itself is a potent risk factor for atherosclerotic CV disease. Both age-associated increase in body fat and reduced physical activity appear to contribute to the impairment of insulin sensitivity and glucose tolerance in older adults. Thus, it is not surprising that both weight reduction and aerobic exercise training ameliorate these impairments. A 9-month aerobic exercise intervention in 71 obese older men (61 ± 1 years, BMI 30.4 ± 0.4 [mean ± SD] ) increased V'O2peak by a mean of 17 % (P < 0.001) and reduced area (under the glyca-emic curve) of an oral glucose tolerance test by an equal amount (Katzel et al., 1995). Bone Density Reduction in bone density associated with aging occurs in both sexes but accelerates in women after menopause, increasing risk for osteoporotic-related fractures, thus, worsening the quality of life. Bonaiuti et al. (2002) reported an increase in bone mineral density of hips and spine by 1.3 % and 0.9 %, respectively (P= 0.055 and P = 0.011, respectively), following walking activity. (Hatori et al., 1993) also showed an increase of bone mineral density of 1.1 ± 2.9 % (P < 0.05) in postmenopausal healthy women (45 to 67 years) following a 7-month training protocol that consisted of 30 minutes of high-intensity walking performed three times per week. Although estrogen replace- Enrico REJC, Alessio DEL TORTO, Stefano LAZZER: BENEFITS OF AEROBIC EXERCISE TRAINING WITH RECOMMENDATIONS ..., 111-124 ment therapy reduces post-menopausal bone loss, the negative cardio vascular effects of estrogen have markedly curtailed its use. It seems worth noting that reduced bone mineral density can represent a potential threat for the health status of an individual. In fact, as mentioned above, reduced bone mineral density can increase the risk of fractures, which affects quality of life and leads to physical inactivity. Fortunately, weight bearing aerobic as well as resistance exercise can increase bone density in older adults by increasing the loading force on bone and stimulating osteoblast activity. Depression In a case-control study, the INERHEART study, it was found that psychological factors (e.g. depression, perceived stress and life events) were strong risk factors for myocardial infarction. Also, depression was officially recognized as a CV risk factor following the 2010 Global Burden of Disease Study and other studies (Yusuf et al., 2004; Elderon & Whooley, 2013). While it seems important to reiterate that modifiable health behaviour (e.g. physical inactivity, poor diet, smoking, dyslipidemia and medication non-adherence) are conceivably the most critical mediators for CV disease, the role of depression on CV diseases and physical (in)activity should be considered (Pan, Sun, Okereke, Rexrode, & Hu, 2011; Hamer, 2012). In fact, some studies reported associations between physical inactivity, depression and CV mortality also in the aged population (Win et al., 2011). In particular, the primary finding of Win and colleagues (2011) was that physical inactivity accounted for approximately 25 % of the increased risk of CV mortality due to depression in community-dwelling aged adults. Furthermore, Whooley et al. (2008) showed that, in a batch of outpatients with stable coronary heart disease, physical inactivity explained almost half of the association between depressive symptoms and CV events. Interestingly, in addition to the beneficial effects of cognitive behavioural therapy and antidepressant medication, regular exercise has been shown to reduce depressive symptoms. For example, Lavie and Milani (1995) have shown lower depression scores, reduced anxiety, and improved total quality of life (QOL) after cardiac rehabilitation (CR) in 85+ coronary patients. The program lasted 12 weeks in which 36 exercise and educational sessions were performed. Each session included: i) around 10 minutes of warm-up stretching and calisthenics; ii) 30 to 40 minutes of continuous upright aerobic and dynamic exercise (various combinations of walking, bicycling, jogging, rowing, etc.), along with light isometric exercises (e.g. hand weights); iii) around 10-minute cool-down period of stretching. The exercise intensity was prescribed with the aim of making patients attain approximately 75 % to 85 % of their maximal heart rate, or 10 to 15 beats per minute below the level of any exercise induced myocardial ischemia. The exercise prescriptions were periodically adjusted to guarantee a gradual increase in exercise performance. Moreover, all patients were oftentimes supported by physicians, dieticians, nurses, and exercise physiologists to comply with the exercise program (Lavie & Milani, 1995). Enrico REJC, Alessio DEL TORTO, Stefano LAZZER: BENEFITS OF AEROBIC EXERCISE TRAINING WITH RECOMMENDATIONS ..., 111-124 LONG-TERM BENEFITS OF EXERCISE IN OLDER ADULTS Despite the study results on physiological benefits of exercise in older adults reviewed above, elderly people are more concerned about their functional independence and QOL than laboratory measurements. As noted earlier, the ability to perform daily activities generally requires an aerobic power > 20 mL/kg/min (Cress & Meyer, 2003). Ehsani et al. (2003) reported a V'O2peak of 15.6 ± 2.7 ml/kg/min in frail octogenarians women; similarly, (Ades, Ballor, Ashikaga, Utton, & Nair, 1996) found a peak aerobic power equal to 21.5 ± 1.1 ml / kg / min in old women (70.4±4 years). These findings highlight the fact that older individuals are extremely close to the threshold for loss of independence (Cress & Meyer, 2003). In this population, regular aerobic training may prevent or significantly delay the crossing of "independence threshold"; furthermore ongoing clinical trials are rigorously examining the effects of regular exercise in preserving independence and reducing morbidity and mortality (Mazzeo & Tanaka, 2001). Older adults are conceivably more concerned about their QOL than their longevity per se. Thus, improving and maintaining high QOL assumes great importance in the aged population. Because QOL is adversely impacted by illness and disability, improved physical function might be expected to cause parallel increases in QOL. In HF--ACTION, a trial of supervised aerobic exercise training followed by home exercise in adults with moderate-to-severe CHF, QOL improved significantly with training (Flynn et al., 2009). Similarly Austin, Williams, Ross, Moseley, & Hutchison (2005) observed improved QOL in 200 patients 60 - 89 years old (mean 72 years) after a 24-week program of aerobic exercise plus low-resistance strength training. Aging is accompanied by an accelerating reduction of functional capacity, best quantified by V'O2max and / or V'O2peak; the degradation of maximal aerobic power is also induced by many comorbidities common to the older individuals (Huggett, Connelly, & Overend, 2005). However, numerous observational and interventional studies have demonstrated the beneficial effects of exercise training in older adults, both in healthy and diseased individuals (Mazzeo & Tanaka, 2001). A major challenge confronting the medical community and society is to increase significantly the participation of the aged population in such activities. RECOMMENDATIONS FOR AEROBIC EXERCISE TRAINING Current recommendations for improving CV fitness and reducing disease risks are certainly effective (Chodzko-Zajko et al., 2009), even though further research is needed to identify the minimum effective dosage for intensity and volume to improve V'O2max and reduce disease and mortality outcomes. These recommendations call for 15 - 60 minutes of aerobic activities that include large muscles, rhythmic movement, 3 - 5 days per week, at an intensity equivalent to 40 - 85 % of V'O2max (55-90% HRmax). This means that practicing exercise at high intensity and volume, just like athletes would, Enrico REJC, Alessio DEL TORTO, Stefano LAZZER: BENEFITS OF AEROBIC EXERCISE TRAINING WITH RECOMMENDATIONS ..., 111-124 is not a prerequisite for significant improvements in CV performance and health status in general. The practice of light- to moderate-intensity physical activity on a more frequent basis, on the other hand, is identified as a requirement to optimize health by the recent guidelines issued by the Centers for Disease Control and Prevention / American College of Sports Medicine (ACSM) (Pate et al., 1995). This should be the main focus of aerobic exercise prescription for adults of all ages (Balady, 2002). Therefore, the ACSM guidelines should provide the basis for exercise prescription for most adults (Chodzko-Zajko et al., 2009). The current consensus recommendations of the ACSM and American Heart Association (AHA) with respect to the frequency, intensity, and duration of exercise and physical activity for older adults are summarized below. The ACSM / AHA Physical Activity Recommendations are generally consistent with the 2008 Physical Activity Guidelines for Americans by the Department of Health and Human Services (DHHS) (Physical Activities Guidelines Advisory Committee, 2008), which also recommend 150 minutes / week of physical activity for health benefits. However, the DHHS Guidelines note that additional benefits occur as the amount of physical activity increases through higher intensity, greater frequency, and / or longer duration. The DHHS Physical Activity Guidelines point out that if older adults cannot perform 150 min of moderate-intensity aerobic activity per week because of chronic conditions, they should be as physically active as their abilities and conditions allow. Main recommendations for aerobic exercise training Frequency: For moderate-intensity activities, accumulate at least 30 or up to 60 (for greater benefit) minutes / day in bouts of at least 10 min each to total 150 - 300 minutes / week, at least 20 - 30 minutes / day or more of vigorous-intensity activities to total 75 - 150 minutes / week, an equivalent combination of moderate and vigorous activity. Intensity: On a scale of 0 to 10 for level of physical exertion, 5 to 6 for moderate-intensity and 7 to 8 for vigorous intensity. Duration: For moderate-intensity activities, accumulate at least 30 minutes / day in bouts of at least 10 min each or at least 20 minutes / day of continuous activity for vigorous-intensity activities. Type: Any modality that does not impose excessive orthopaedic stress; walking is the most common type of activity. Aquatic exercise and stationary cycle exercise may be advantageous for those with limited tolerance for weight bearing activity. Despite the extremely favourable health outcomes promoted by the above described physical activity, it may be argued that the proposed exercise guidelines are too generic. The adoption of a common prescription approach may not allow to achieve the full therapeutic potential of physical exercise treatment. In fact, these guidelines do not take into account some crucial aspects of exercise prescription, such as the recovery period among each training session (especially between the ones carried out at high intensity and / or high volume) as well as training periodization and the individualization of Enrico REJC, Alessio DEL TORTO, Stefano LAZZER: BENEFITS OF AEROBIC EXERCISE TRAINING WITH RECOMMENDATIONS ..., 111-124 training variables (volume, intensity and frequency) based on the individual needs of the older individuals. In particular, it is known that periodized training promotes better physical improvements compared to non-periodized training programs in the healthy population, and this may conceivably be the case also for non-healthy individuals (Issurin, 2010). Another positive aspect of periodization is the reduced risk of overtraining and its side effects (Fry, Morton, & Keast, 1992). ACSM guidelines also reported that exercise and physical activity progression for older adults should be individualized, also using exercise tolerance as an additional criteria (Chodzko-Zajko et al., 2009). CONCLUSIONS A body of evidence clearly indicates that involvement in exercise programs induces several benefits for older individuals. These favourable ameliorations involve noteworthy health-related issues including CV disease, metabolic syndrome, diabetes mellitus and osteoporosis. 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Lancet 364(9438), 937-952. doi: 10.1016/S0140-6736(04)17018-9 VIEW ITEM Review article received: 2017-05-31 UDC: 612.74:796.012 EXERCISE EFFECTS ON MUSCLE STEM CELLS Mihaela JURDANA1 'University of Primorska, Faculty of Health Sciences, Izola, Slovenia Corresponding author: Mihaela JURDANA, PhD, University of Primorska, Faculty of Health Sciences Izola, Polje 42, 6310 Izola, Slovenia. Tel.: +386 5 66 26 469 e-mail: mihaela.jurdana@fvz.upr. si ABSTRACT Satellite cells are skeletal muscle stem cells that facilitate muscle repair and regeneration after "damage" which occurs after physiological stimuli: exercise, post-training micro-injuries and electrical stimulation. Exercise stimuli lead to activation and proliferation of these cells from their quiescent state, therefore, increasing cell numbers having the potential to provide additional myonuclei to their parent muscle fibre or return to a quiescent state. Different exercise modalities are the focus ofnumerous studies on satellite cells activation. An increase in muscle activity augments satellite cells proliferation as well as skeletal muscle mass and function, both in young and elderly. This review provides an updated view of the contribution of skeletal muscle satellite cells in regulating skeletal muscle mass and the efficiency of the exercise intervention to attenuate the decline in muscle mass. Keywords: Satellite cells, acute and chronic exercises, micro damage, muscle regeneration. UČINEK TELESNE AKTIVNOSTI NA SKLETNO-MIŠIČNE STAMINALNE CELICE IZVLEČEK Satelitske celice so skeletno-mišične staminalne celice, ki omogočajo popravilo in regeneracijo mišičnih vlaken po mikropoškodbah, kot je telesna aktivnost, trening ali Mihaela JURDANA: EXERCISE EFFECTS ON MUSCLE STEM CELLS ..., 125-135 električna stimulacija. Telesna aktivnost sproži prehod satelitskih celic iz stanja mirovanja v aktivacijo in proliferacijo, kar jim omogoča, da se namnožijo in povečajo svoje število. Novonastale satelitske celice se lahko vežejo na matično mišično vlakno ali preidejo v stanje mirovanja. Veliko študij preučuje, kako različne oblike vadbe vplivajo na aktivacijo satelitskih celic ter njihovo število. Znano je, da mišična aktivnost povečuje proliferacijo satelitskih celic, posledično tudi mišično maso in funkcijo, tako pri mladih kakor tudi pri starejših osebah. Pregled literature v tem članku prikazuje posodobljen pogled na vlogo satelitskih celic pri vzdrževanju mišične mase in pomembnost vloge telesno/gibalne aktivnosti v preventivi pred izgubo le-te. Ključne besede: Satelitske celice, akutna in kronična vadba, mikro poškodbe, mišična regeneracija INTRODUCTION Skeletal Muscle Regeneration Skeletal muscle regeneration is a highly integrated process involving the activation of various cellular and molecular responses; skeletal muscle stem cells play a pivotal role in this process. Adult skeletal muscle is a stable post-mitotic tissue, small daily injury can be repaired without causing inflammatory responses and cell death. Muscle injury such as extensive physical activity is related to myofibre necrosis, inflammatory responses, and activation, differentiation, and fusion of satellite cells. Muscle regeneration includes the above mentioned processes with a new myofibre formation. Mammalian skeletal muscles consist of different multinucleated myofibers, grouped in slow (type 1) and fast types (2A, 2X, and 2B) with different myosin heavy chain (MyHC) composition. Myofibres also differ in their metabolic profile, extending from slow /oxidative to fast / glycolytic (Schiaffino & Reggiani, 2011). The maintenance of skeletal muscle mass depends on mono nucleated muscle precursors or muscle satellite cells. In addition, pericytes, resident in small vessels of skeletal muscle, contribute to its growth and regeneration during postnatal life (Dellavalle et al., 2011). Satellite cells were identified over 50 years ago through electron microscopy by Mauro in 1961. The satellite cell population varies by age, muscle type, and activity, and are used during muscle regeneration and repair due to their special self-renewal and multi-differentiation capabilities. At birth, satellite cells account for 15 % of the entire myofibre nuclei population (Thornell, Lindstrom, Renault, Mouly, & Butler-Browne, 2003). That proportion latter decreases to between 1 % and 6 % of total myonuclear content in mature muscle fibres (Roth et al., 2000). The major function of satellite cells is contribution to the maintenance of muscle mass, regeneration, and Mihaela JURDANA: EXERCISE EFFECTS ON MUSCLE STEM CELLS ..., 125-135 hypertrophy by differentiating into myocytes during human's lifespan. Satellite cells are normally non-proliferative, mitotically quiescent and they become activated in response to stimuli such as myotrauma upon injury or muscle growth (Bischoff & Heintz, 1994), or when skeletal muscle tissue is heavily used during physical activities such as weight lifting or running. When skeletal muscle is injured, damaged or exercised, satellite cells are activated from their quiescent state, proliferated and fused into existing fibres to provide new myonuclei or return to quiescence (Dhawan & Rando, 2005). Activation of those cells is not restricted to the site of muscle damage. Satellite cells are activated, migrate and proliferate from different parts of myofibre. However, the number of satellite cells appears to increase in the end part of myofibres, where longitudinal elongation of the skeletal muscle occurs (Yin, Price, & Rudnicki, 2013). Importantly, satellite cells have a limited capacity of division entering a state of irreversible growth arrest after a finite number of cell division (Chargé & Rudnicki, 2004). The self-renewing proliferation of satellite cells maintains the stem cell population and provides abundant myogenic cells which proliferate, differentiate, and fuse to generate new myofibre formation (Yin et al., 2013). With these additional nuclei, muscle fibres can synthesize more proteins and create more contractile myofilaments (actin and myosin) in skeletal muscle cells (Chargé & Rudnicki, 2004). It is interesting to note that high numbers of satellite cells are found associated to slow-twitch muscle fibres as compared to fast-twitch muscle fibres within the same muscle, as they are regularly going through cell maintenance repair from daily activities (Martin & Lewis 2012). As satellite cells are constantly replenished during lifetime and are essential for muscle fibre maintenance, a decline in number and reduced proliferative capacity of satellite cells and / or their inability to become activated and proliferate upon stimuli might contribute to muscle fibre atrophy observed in the elderly (Bischoff, 1994; Seale & Rudnicki, 2000). Many researchers are interested in new training programs and exercise for developing skeletal muscle mass. However, the mechanism(s) by which exercise induces skeletal muscle hypertrophy remain poorly understood. Through exercise, the muscular work done against progressively challenging overloads leads to increases in muscle mass. Individual satellite cells respond to exercise and they are influenced by such factors as training status, age, nutrition, and the intensity and volume of the exercise. Duration, frequency and intensity of exercise are important contributing factors in satellite cells activation. Passive stretching of contracted muscles may cause multiple micro damages, disruption of contractile elements or necrosis. For many of us, this happens after changes in the locomotor behaviour by severe onset of exercise. Also after 20 minutes of stepping up and down induces a remarkable increase in muscle-derived proteins in plasma, which reflects some muscle damage (Wernig, 2003). It has been shown that the intensity of the exercise is an important factor in satellite cells activation and muscle regeneration (Martin & Lewis, 2012). Similarly, other researchers have demonstrated that an increase in satellite cell content depends on the intensity rather than the duration Mihaela JURDANA: EXERCISE EFFECTS ON MUSCLE STEM CELLS ..., 125-135 of exercise (Bazgir, Fathi, Rezazadeh Valojerdi, Mozdziak, & Asgari, 2017). Intensive exercise such as resistance training bout induces damage to the muscle fibres, causing activation and proliferation of satellite cells. This biological effort often leads to increasing in muscle fibre cross-section area or hypertrophy (Bischoff, 1994). On the other hand, various muscle groups and types react differently to intensity and volume of exercise. During muscle hypertrophy, muscle fibre size appears to be related to the size of the myonuclear domain, defined as the amount of cytoplasm within a muscle fibre controlled by single myonuclei (Hall & Ralston, 1989). Protein synthesis of single my-onuclei is confined in myonuclear domain. The amount of cytoplasm controlled by each myonuclei in adult muscle fibre is relatively constant, thus supporting the theory that satellite cells are required for muscle hypertrophy in order to keep the myonuclear domain constant. Considering the presence of other stem cells in skeletal muscle, their contribution in muscle regeneration and hypertrophic growth is possible (Blaauw & Reggiani, 2014). METHODS Electronic databases MEDLINE, PubMed, and Science Direct including the articles published up to 2017 were used to search literature sources. Different keywords were used: satellite cells (SC), SC during exercise, skeletal muscle regeneration and hypertrophy, SC during ageing. Based on the keywords and review articles, satellite cells activation and proliferation during exercise was described. RESULTS Satellite Cell during Ageing It is well known that impairments in satellite cell function during aging result in an impaired muscle fibre regenerative response (Sousa & Munoz-Canoves, 2016; Snijders & Parise, 2017) leading to the gradual loss of muscle mass and function (sarcopenia) which diminishes muscle recovery after injury in elderly individuals. In many cases this leads to disability and the subsequent loss of independence. A lower number of satellite cell pool and the exhausted proliferative capacity of aged satellite cells may contribute to accelerated loss of skeletal muscle mass during ageing (Renault, Thorne, Eriksson, Butler-Browne, & Mouly, 2002; Sajko et al., 2004; Joanisse, Nederveen, Snijders, McKay, & Parise, 2017). Other possible reasons for impaired muscle recovery in elderly individuals relate to the reduced production of growth factors or affect the e-c (excitation-contraction) coupling mechanism (muscle-contracting mechanism), (Delbono, O'Rourke, & Ettinger, 1995). It has also been demonstrated that inadequate muscle fibre vascularization occurring during ageing process Mihaela JURDANA: EXERCISE EFFECTS ON MUSCLE STEM CELLS ..., 125-135 may be an important cause of impaired regulation of satellite cells in older adults (Snijders & Parise, 2017). A certain number of satellite cells seems to be necessary for muscle regeneration during the ageing process. Bengal's recent review (Bengal, Perdiguero, Serrano, & Muñoz-Cánoves, 2017) has identified the network of cell-intrinsic and cell-extrinsic factors and processes contributing to satellite cells decline during ageing. Most of the studies suggest that the mentioned decline is caused by age-associated extrinsic (environmental changes) and intrinsic mechanisms (DNA damage, oxidative stress). Both mechanisms contribute to muscle stem cell dysfunction. Based on this idea, many studies propose to rejuvenate aged satellite cells to improving muscle repair in the elderly. (Rando & Chang, 2012; Bengal et al., 2017). Other studies proposed that inadequate activation of Notch signalling, necessary for cell proliferation and cell fate determination, contributes to the loss of regenerative proprieties of aged skeletal muscle (Conboy, Conboy, Smythe, & Rando, 2003; Bjornson et al., 2012). Satellite Cells Activation and Proliferation after Exercise Resistance and endurance types of exercise training improve muscle mass and strength, and increase the performance capacity in young and elderly. Satellite cells are involved in muscle maturation during postnatal development, regeneration after injury, hypertrophy, hyperplasia and atrophic post-muscle recovery (Dhawan & Rando, 2005; Chargé & Rudnicki, 2004). The increase of satellite cell proliferation and activation takes place after short-term muscle activity (Darr & Schultz, 1987), but the increases in satellite cell numbers only occur after a long term resistance or endurance training (Martin & Lewis, 2012). Many studies reported the result of a number of satellite cells following exercise in human (Table 1). Satellite cells get activated from their quiescent state and are involved in muscle regeneration after micro-injuries that follow exercise. Satellite cell content and activity after endurance training can be correlated with time and intensity, duration and frequency of exercise. It has been observed that satellite cell content increased after 30 to 155 minutes of moderate to high-intensity endurance exercises (Parise, McKinnell, & Rudnicki, 2008; Van de Vyver & Myburgh, 2012; Bazgir et al., 2017), while no such increase was associated after 30 minutes of low-intensity exercise (Smith, Maxwell, Rodgers, McKee, & Plyley, 2001). These data confirm the role of the intensity of exercise in satellite cell activation and their role in regeneration and muscle repair. The acute satellite cell response to exercise has been examined in humans using maximal eccentric contractions of the vastus lateralis muscle by isokinetic dynamom-etry, as eccentric exercise is considered to induce maximal levels of muscle damage (Gibala, MacDougall, Tarnopolsky, Stauber, & Elorriaga, 1995). Indeed, it appears that the satellite cell response to acute exercise in humans occurs during the first 24 hours after eccentric exercise, however, there was a significant increase in satellite cells Mihaela JURDANA: EXERCISE EFFECTS ON MUSCLE STEM CELLS ..., 125-135 Table 1: Summarized studies on human satellite cell numbers following different exercise type (Martin & Lewis, 2012). Acute/chronic Training Exercise type Muscle Analysed Satellite Cell number References Acute exercise training RT VL increase Crameri et al. 2004 RT VL increase Dreyer et al. 2006 RT VL increase O'Reilly et al. 2008 RT VL increase McKay et al. 2009 ES VL increase Mackey et al. 2012 increase Mackey et al. 2009 Chronic training RT VL increase Roth et al. 2001 RT VL # increase Petrella et al. 2008 RT VL increase Mackey et al. 2010 RT VL increase Kadi et al. 2004 RT VL increase Mackey et al., 2007 RT VL increase Verdijk et al. 2009 RT TR increase Kadi and Thor-nell, 2000 RT, ET EDL, VL increase Verney et al. 2008 ET Pl * increase Kurosaka et al. 2011 ET VL increase Charifi et al. 2003 ET VL increase Shefer et al. 2010 Abbreviations: RT= Resistance training, ET= Endurance training, EDL= Extensor digitorum longus, ES= Electrical stimulation, VL=Vastus lateralis, Pl= Plantaris, Tr= Trapezius, * increase of SC number only with high intensity training. # increase of SC number only seen in individuals who responded most robustly to RT. Mihaela JURDANA: EXERCISE EFFECTS ON MUSCLE STEM CELLS ..., 125-135 over pre-exercise values even at later times (O'Reilly et al., 2008). Therefore, satellite cells get activated and proliferated in 24 hours after exercise, and increase considerably between 72 and 96 hours, thereafter they decline in number. (McKay et al., 2009; O'Reilly et al. 2008). The research data on humans suggest that resistance and endurance training can increase satellite cell content and activation in response to exercise periods from 9 to 16 weeks. (Kadi, Charifi, Denis, & Lexell, 2004; Petrella, Kim, Mayhew, Cross, & Bam-man, 2008; Shefer, Rauner, Yablonka-Reuveni, & Benayahu, 2010). However, it should be noted that the resistance type of training leads to an expansion in satellite cell pool with myonuclear addition (Petrella et al., 2008). Muscle fatigue seems to be a stimulus for activation, proliferation and differentiation of satellite cells. Unfortunately, there is little research available that compares satellite cells quantity in response to endurance exercise and resistance exercise. Verney et al. (2008) observed an increase in satellite cell content in the deltoid (resistance-trained) and VL (endurance-trained) muscles after 14 weeks in elderly individuals. Interestingly, a failure in increasing the satellite cell pool after a training intervention was observed in obese, diabetic population (Snijders, Verdijk, Hansen, Dendale, & van Loon, 2011). As to animal models, a study on rat soleus muscle showed no increase in satellite cell content after one week of running for 30 minutes per day on treadmill (Smith et al., 2001). While a similar study on mice anterior tibialis muscle reported a significant increase in the satellite cell number and activation (Parise et al., 2008), due to the different composition of muscle fibre type. The study of Smith and Merry (2012) described a six-week resistance type or endurance type of exercise in rats and found no difference between the proportional gains in satellite cell number of the same muscles between groups. These data suggest that endurance and resistance training enhance the satellite cell pool to a similar extent (Marin & Lewis 2012). In addition, a differential response in fibre-type expansion of satellite cells in response to exercise was observed. Fibre-type classification demonstrates that satellite cells are not equally distributed among the various fibre types and muscles. In human studies, no difference has been detected in satellite cell numbers between fibre types in vastus lateralis untrained muscle of young healthy individuals (Kadi et al., 2006; Verdijk et al., 2007; Snijders et al., 2012), while other studies revealed a greater number of satellite cells in type I fibres and, consequently, minor adaptive potential (Martin & Lewis, 2012; Bazgir et al., 2017). It was demonstrated that untrained rodent muscle type I fibres contain a greater number of satellite cells in respect to type II fibres. In response to training, the number of satellite cells in type II fibre was increased, while the same increase was not observed in type I (Verdijk et al., 2009; Smith & Merry, 2012). This process seems sensible as type II fibres give a greater contribution to muscle mass (hypertrophy) and show a higher responsiveness to resistance training (Martin & Lewis 2012; Bazgir et al., 2017). All these data underline the need of future investigation because the mechanisms of exercise-induced satellite cells activation are not completely understood. Mihaela JURDANA: EXERCISE EFFECTS ON MUSCLE STEM CELLS ..., 125-135 CONCLUSION The maintenance of skeletal muscle mass and regenerative capacity depends on a functional pool of muscle satellite cells. A loss of skeletal muscle satellite cells and defects in their activity are associated with a variety of neuromuscular and other disorders which lead to muscle atrophy. Exercise training has been successfully applied to augment satellite cells muscle mass and improve muscle function also in elderly. It has been demonstrated that satellite cell activation after exercise together with adequate nutrition are the most effective countermeasures for ageing sarcopenia. Modalities of exercise, intensity, duration and frequency are correlated with satellite cell content. 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Muscle satellite cell and atypical myogenic progenitor response following exercise. Muscle & Nerve, 37(5), 611-619. doi: 10.1002/mus.20995 VIEW ITEM Petrella, J. K., Kim, J. S., Mayhew, D. L., Cross, J. M., & Bamman, M. M. (2008). Potent myofiber hypertrophy during resistance training in humans is associated with satellite cell-mediated myonuclear addition: A cluster analysis. Journal of Applied Physiology, 104(6), 1736-1742. doi: 10.1152/japplphysiol.01215.2007 VIEW ITEM Mihaela JURDANA: EXERCISE EFFECTS ON MUSCLE STEM CELLS ..., 125-135 Rando, T. A., & Chang, H. Y. (2012). Aging, rejuvenation, and epigenetic reprogramming: Resetting the aging clock. Cell, 148(1-2), 46-57. doi: 10.1016/j.cell.2012.01.003 VIEW ITEM Renault, V., Thorne, L. E., Eriksson, P. O., Butler-Browne, G., & Mouly, V. (2002). Regenerative potential of human skeletal muscle during aging. Aging Cell, 1(2), 132-139. doi: 10.1046/j.1474-9728.2002.00017.x VIEW ITEM Roth, S. M., Martel, G. F., Ivey, F. M., Lemmer, J. T, Metter, E. J., Hurley, B. F., & Rogers, M. A. (2000). Skeletal muscle satellite cell populations in healthy young and older men and women. Anatomical Record, 260(4), 351-358. doi: 10.1002/1097-0185(200012)260:4<350::AID-AR30>3.0.C0;2-6 VIEW ITEM Sajko, Š., Kubinova, L., Cvetko, E., Kreft, M., Wernig, A., & Eržen, I. (2004). Frequency of M-cadherin-stained satellite cells declines in human muscles during aging. Journal of Histochemistry & Cytochemistry, 52(2), 179-185. doi: 10.1177/002215540405200205 VIEW ITEM Seale, P., & Rudnicki, M. A. (2000). A new look at the origin, function, and "stem-cell" status of muscle satellite cells. Developmental biology, 218(2), 115-124. doi: 10.1006/ dbio.1999.9565 VIEW ITEM Shefer, G., Rauner, G., Yablonka-Reuveni, Z., & Benayahu, D. (2010). Reduced satellite cell numbers and myogenic capacity in aging can be alleviated by endurance exercise. PLoS One, 5(10), e13307. doi: 10.1371/journal.pone.0013307 VIEW ITEM Sousa-Victor, P., & Munoz-Canoves, P. (2016). Regenerative decline of stem cells in sar-copenia. Molecular aspects of medicine, 50, 109-117. doi: 10.1016/j.mam.2016.02.002 VIEW ITEM Smith, H. K., Maxwell, L., Rodgers, C. D., McKee, N. H., & Plyley, M. J. (2001). Exercise-enhanced satellite cell proliferation and new myonuclear accretion in rat skeletal muscle. Journal of Applied Physiology, 90(4), 1407-1414. doi: 10.1152/ja-ppl.2001.90.4.1407 VIEW ITEM Smith, H. K., & Merry, T. L. (2012). Voluntary resistance wheel exercise during post-natal growth in rats enhances skeletal muscle satellite cell and myonuclear content at adulthood. Acta physiologica, 204(3), 393-402. doi: 10.1111/j.1748-1716.2011.02350.x VIEW ITEM Schiaffino, S., & Reggiani, C. (2011). Fiber types in mammalian skeletal muscles. Physiological reviews, 91(4), 1447-1531. doi: 10.1152/physrev.00031.2010 VIEW ITEM Snijders, T., & Parise, G. (2017). Role of muscle stem cells in sarcopenia. Current Opinion in Clinical Nutrition & Metabolic Care, 20(3), 186-190. doi: 10.1097/ MC0.0000000000000360 VIEW ITEM Snijders, T., Verdijk, L. B., Beelen, M., McKay, B. R., Parise, G., Kadi, F., & van Loon, L. J. (2012). A single bout of exercise activates skeletal muscle satellite cells during subsequent overnight recovery. Experimental Physiology, 97(6), 762-773. doi: 10.1113/ expphysiol.2011.063313 VIEW ITEM Snijders, T., Verdijk, L. B., Hansen, D., Dendale, P., & van Loon, L. J. (2011). Continuous endurance-type exercise training does not modulate satellite cell content in obese type 2 diabetes patients. Muscle & Nerve, 43(3), 393-401. doi: 10.1002/mus.21891 VIEW ITEM Thornell, L. E., Lindstrom, M., Renault, V., Mouly, V. & Butler-Browne, G. S. (2003). Satellite cells and training in the elderly. 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Satellite cell content is specifically reduced in type II skeletal muscle fibers in the elderly. American Journal of Physiology Endocrinology and Metabolism, 292(1), E151-E157. doi: 10.1152/ajpendo.00278.2006 VIEW ITEM Verney, J., Kadi, F., Charifi, N., Feasson, L., Saafi, M. A., Castells, J., et al. (2008). Effects of combined lower body endurance and upper body resistance training on the satellite cell pool in elderly subjects. Muscle & Nerve, 38(3), 1147-1154. doi: 10.1002/ mus.21054 VIEW ITEM Wernig, A. (2003). Regeneration capacity of skeletal muscle. Therapeutische Umschau, 60(7), 383-389. doi: 10.1024/0040-5930.60.7.383 VIEW ITEM Yin, H., Price, F., & Rudnicki, M. A. (2013). Satellite cells and the muscle stem cell niche. Physiological Reviews, 93(1), 23-67. doi: 10.1152/physrev.00043.2011 VIEW ITEM REPORTS AND REVIEWS/POROCILA IN OCENE, 137-142 MEDITERRANEAN HEALTH CENTRE Institute for Kinesiology Research of the Science and Research Centre Koper Arena Bonifika, Koper, Slovenia; December 13th, 2017 On December 13th, 2017, Institute for Kinesiology Research of the Science and Research Centre Koper held an opening ceremony of its new Mediterranean Health Centre. The Centre was established with a strong support of the Municipality of Koper and will significantly add to the development of sports activities locally as well as in the wider region. With the cooperation of the team of experts from the nearby Izola General Hospital, the main purpose of the Centre is to give support in rehabilitation after sports injuries. A solemn opening ceremony was introduced with a speech held by the Head of the Institute for Kinesiology Research of the ZRS Koper, Assoc. Prof. Boštjan Šimunič, Ph.D., who summarized the past achievements of the Institute. Prof. Rado Pišot, Ph.D., Director of ZRS Koper, further explained the planned purposes of the new Mediterranean Health Centre premises. He pointed out the Center's general support of active healthy living and of the widely acknowledged Mediterranean lifestyle. Its main focus is going to be on functional diagnostics, development and planning of modern and holistic exercise programs, rehabilitation programs designed to the specific individual needs, thus, providing safe and quick return of active sportsmen and women to their activities and designing healthy ergonomic working conditions. The Municipality of Koper has been a strong supporter of the Centre since the beginning. As the Mayor, Mr. Boris Popovič put it, it represents an important step towards the realization of a long-time ambition of the Municipality of Koper to become an important destination of sports tourism. The support given to the opening of the Medi- REPORTS AND REVIEWS/POROCILA IN OCENE, 137-142 REPORTS AND REVIEWS/POROCILA IN OCENE, 137-142 terranean Health Centre was also expressed by the President of the Slovenian Olympic Committee Mr. Bogdan Gabrovec, and the Head of the Institute of Sports Medicine of the Faculty of Medicine of the University of Maribor, Assoc. Prof. Matjaz Vogrin, M.D., Ph.D. With this even, the Institute for Kinesiology Research of the ZRS Koper rounded up the year 2017 that can be marked as a successful one. It was the year in which the Institute obtained two important and worldwide acknowledged accreditations, namely a FIFA Medical Centre of Excellence (in collaboration with the Institute of Sports Medicine of the Faculty of Medicine of the University of Maribor, the Brdo National Football Centre and Maribor University Medical Centre) and an Olympic Sports Medicine Centre (in collaboration with Izola General Hospital), the latter providing sportsmen with fast and efficient injury diagnostics and first aid. The Centre opening earned special acknowledgement by the President of UEFA, Mr. Aleksander Ceferin, who sent his congratulations to the entire team of the Institute for Kinesiology Research of the ZRS Koper. Matej Kleva REPORTS AND REVIEWS/POROCILA IN OCENE, 137-142 MEDITERANSKI CENTER ZDRAVJA Inštitut za kineziološke raziskave, Znanstveno-raziskovalno središče Koper Arena Bonifika, Koper, 13. December 2017 V koprski Areni Bonifika je 13. decembra 2017 Inštitut za kineziološke raziskave Znanstveno-raziskovalnega središča Koper (ZRS) slovesno odprl prostore Mediteranskega centra zdravja. Center, ki je zaživel ob podpori Mestne občine Koper, bo pomembno prispeval k razvoju športa v lokalnem okolju in širše, v prvi vrsti pa bo ob sodelovanju strokovnjakov Splošne bolnišnice Izola (SBI) namenjen rehabilitaciji posameznikov po športnih poškodbah. Svečana otvoritev se je pričela z uvodnim pozdravom predstojnika Inštituta za ki-neziološke raziskave, ZRS Koper, dr. Boštjana Šimuniča, ki je povzel vse dosedanje dosežke Inštituta, ki ga vodi. Direktor ZRS Koper, prof. Rado Pišot, je v nadaljevanju pojasnil, da bodo novi prostori Mediteranskega centra zdravja namenjeni vsesplošni podpori zdravju, ki bo slonela na mediteranskem življenjskem slogu s svetovno priznanim znakom odličnosti. Aktivnosti centra bodo osredotočene na funkcionalno diagnostiko, razvoj in načrtovanje sodobnih in celostnih programov vadbe in rehabilitacije po meri posameznikov, z zagotavljanjem varnega vračanja po poškodbah pa tudi načrtovanju zdravega delovnega okolja. Odprtje centra je omogočila Mestna občina Koper, saj sodeč po besedah župana, gospoda Borisa Popoviča, Mediteranski center zdravja predstavlja pomemben korak k uresničitvi dolgoletnih prizadevanj občine, da bi Koper postal tudi športno-turistič-ni center. Podporo odprtju Mediteranskega centra zdravja sta izrazila tudi predsednik Olimpijskega komiteja Slovenije, gospod Bogdan Gabrovec in predstojnik Inštituta za športno medicino Medicinske fakultete Univerze v Mariboru, dr. Matjaž Vogrin. REPORTS AND REVIEWS/POROCILA IN OCENE, 137-142 REPORTS AND REVIEWS/POROCILA IN OCENE, 137-142 Inštitut za kineziološke raziskave ZRS Koper, je s tem dogodkom zaključil uspešno leto 2017, v katerem je pridobil dve pomembni mednarodni akreditaciji - FIFA medicinski center odličnosti (v sodelovanju z Inštitutom za športno medicino Medicinske fakultete v Mariboru, Centrom NZS Brdo in UKC Maribor) in Olimpijski referenčni športno-medicinski center (v sodelovanju s Splošno bolnišnico Izola), v katerem bodo športniki po diagnostiki dobili hitro pomoč. Obe akreditaciji sta svoj sedež dobili v Mediteranskem centru zdravja. Hkrati se s tem imenovanjem zaokrožuje slovenska mreža referenčnih medicinskih centrov. Ob odprtju Mediteranskega centra zdravja je čestitke Inštitutu za kineziološke raziskave ZRS Koper poslal tudi predsednik UEFE, gospod Aleksander Čeferin. Matej Kleva GUIDELINES FOR AUTHORS, 143-146 GUIDELINES FOR AUTHORS 1. Aim and scope of the journal: Annales Kinesiologiae is an international interdisciplinary journal covering kinesiology and its related areas. It combines fields and topics directed towards the study and research of human movement, physical activity, exercise and sport in the context of human life style and influences of specific environments. The journal publishes original scientific articles, review articles, technical notes and reports. 2. General policy of Annales Kinesiologiae Annales Kinesiologiae pursues the multi-disciplinary aims and nature of Kinesiology with the main goal to promote high standards of scientific research. a) Reviewing: Each manuscript, meeting the technical standards and falling within the aims and scope of the journal, will be subjected to a double-blind peer-review by two reviewers. Authors can propose up to two reviewers for revision of their work and also up to two reviewers they would like to avoid. The referees are chosen by the Editors. Assessments by the referees will be presented anonymously to the author and will be returned to the author for correction. The corrected copy of the manuscript, with the list of corrections on a separate page, should be returned to the responsible Editor. b) Permissions: Authors wishing to include figures, tables, or text passages that have been published elsewhere, are required to obtain permission from the copyright owner(s) and to include evidence that such permission has been granted when submitting their manuscript. Any material received without such evidence it will be assumed that the authors hold the copyright. c) Cover letter: The submitting material, needs to include a cover letter with the contact data including postal address, telephone number, and email address of the corresponding author. The letter should clearly state that the material submitted is unpublished and original and has not and will not be submitted for publication elsewhere until a decision is made regarding its acceptance for publication in Annales Kinesiologiae. The use of human participants or animals should be approved by an ethics committee and shall be clearly stated in the Methods section of the submitted manuscript. d) Copyright agreement: After the editorial acceptance of the manuscript, the corresponding author will be asked to fill in the copyright agreement for which a paper copy needs to be received at the secretary of Annales Kinesiologiae. 3. Manuscript preparation a) Language and style: The language of Annales Kinesiologiae is USA English. The authors are responsible for the language, grammar, and style of the manuscript, which need to meet the criteria defined in the guidelines for authors. Manuscripts are required to follow a scientific style style. The journal will be printed in grayscale. b) The length of the manuscript should not exceed 36,000 characters (excluding spaces). GUIDELINES FOR AUTHORS, 143-146 Text formatting: It is required to use the automatic page numbering function to number the pages. Times New Roman font size 12 is recommended, with double spacing between lines. Use the table function, not spreadsheets, to make tables. Use an equation editor for equations. Finally, all lines need to be number, were the first line of a pages is assigned line number 1. c) Miscellaneous: Whenever possible, use the SI units (Système international d'unités). d) The title page should include the title of the article (no more than 85 characters, including spaces), full names of the author(s) and affiliations (institution name and address) of each author; linked to each author using superscript numbers, as well as the corresponding author's full name, telephone, and e-mail address. e) The authors are obliged to prepare two abstracts - one short abstract in English and one (translated) in Slovene language. For foreign authors translation of the abstract into Slovene will be provided. The content of the abstract should be structured into the following sections: purpose, methods, results, and conclusions. It should only contain the information that appears in the main text, and should not contain reference to figures, tables and citations published in the main text. The abstract is limited to 250 words. f) Under the abstract a maximum of 6 appropriate Keywords shall be given in English and in Slovene. For foreign authors the translation of the key words into Slovene will be provided. g) The main text should include the following sections: Introduction, Methods, Results, Discussion, Conclusions, Acknowledgement (optional), and References. Individual parts of the text can form sub-sections. h) Each table should be submitted on a separate page in a Word document after the Reference section. Tables should be double-spaced. Each table shall have a brief caption; explanatory matter should be in the footnotes below the table. Abbreviations used in the tables must be consistent with those used in the main text and figures. Definitions of symbols should be listed in the order of appearance, determined by reading horizontally across the table and should be identified by standard symbols. All tables should be numbered consecutively Table 1, etc. The preferred location of the table in the main text should be indicated preferably in a style as follows: *** Table 1 somewhere here ***. i). Captions are required for all figures and shall appear on a separate manuscript page, under the table captions. Each figure should be saved as a separate file without captions and named as Figure 1, etc. Files should be submitted in *.tif or *.jpg format. The minimum figure dimensions should be 17x20 cm and a resolution of at least 300 dpi. Combinations of photo and line art should be saved at 600-900 dpi. Text (symbols, letters, and numbers) should be between 8 and 12 points, with consistent spacing and alignment. Font type may be Serif (Times Roman) or Sans Serif (Arial). Any extra white or black space surrounding the image should be cropped. Ensure that participant-identifying information (i.e., faces, names, or any other identifying features) should be omitted. Each figure should be saved as a separate file without captions and named as Figure 1, etc. The preferred location of the figure in the main text should be indicated preferably in a style as follows: *** Figure 1 somewhere here ***. GUIDELINES FOR AUTHORS, 143-146 j) References The journal uses the Harvard reference system (Publication Manual of the American Psychological Association, 5th ed., 2001). see also: http://www.apastyle.org). The list of references should only include work cited in the main text and being published or accepted for publication. Personal communications and unpublished works should only be mentioned in the text. References should be complete and contain up to six authors. If the author is unknown, start with the title of the work. If you are citing work that is in print but has not yet been published, state all the data and instead of the publication year write "in print". Reference list entries should be alphabetized by the last name of the first author of each work. Titles of references written in languages other than English should be additionally translated into English and enclosed within square brackets. Full titles of journals are required (no abbreviations). Examples of reference citation in the text One author: This research spans many disciplines (Enoka, 1994) or Enoka (1994) concluded... Two authors: This result was later contradicted (Greene & Roberts, 2005) or Greene and Roberts (2005) pointed out... Three to five authors: a) first citation: Simunic, Pisot and Rittweger (2009) found... or (Simunic, Pisot & Rittweger, 2009) b) Second citation: Simunic et al. (2009) or (Simunic et al., 2009) Six or more authors: Only the first author is cited: Di Prampero et al. (2008) or (Di Prampero et al., 2008). Several authors for the same statement with separation by using a semicolon: (Biolo et al., 2008; Plazar & Pisot, 2009) Examples of reference list: The style of referencing should follow the examples below: Books: Latash, M. L. (2008). Neurophysiologic basis of movement. Campaign (USA): Human Kinetic. Journal articles Marusic, U., Meeusen, R., Pisot, R., & Kavcic, V. (2014). The brain in micro- and hypergravity: the effects of changing gravity on the brain electrocortical activity. European journal of sport science, 14(8), 813-822. DOI: 10.1080/17461391.2014.908959. De Boer, M. D., Seynnes, O., Di Prampero, P., Pisot, R., Mekjavic, I., Biolo, G., et al. (2008). Effect of 5 weeks horizontal bed rest on human muscle thickness and architecture of weight bearing and non-weight bearing muscles. European Journal of Applied Physiology, 104(2), 401-407. GUIDELINES FOR AUTHORS, 143-146 Book chapters Šimunič, B., Pišot, R., Mekjavic, I. B., Kounalakis, S. N., & Eiken, O. (2008). Orthostatic intolerance after microgravity exposures. In R. Pišot, I. B. Mekjavic, & B. Šimunič (Eds.), The effects of simulated weightlessness on the human organism (pp. 71-78). Koper: University of Primorska, Scientific and Research Centre of Koper, Publishing house Annales. Rossi, T., & Cassidy, T. (in press). Teachers' knowledge and knowledgeable teachers in physical education. In C. Hardy, & M. Mawer (Eds.), Learning and teaching in physical education. London (UK): Falmer Press. Conference proceeding contributions Volmut, T., Dolenc, P., Šetina, T., Pišot, R., & Šimunič, B. (2008). Objectively measured physical activity in girls and boys before and after long summer vacations. In V. Štemberger, R. Pišot, & K. Rupret (Eds.) Proceedings 5th International Symposium A Child in Motion "The physical education related to the qualitative education" (pp. 496-501). Koper: University of Primorska, Faculty of Education Koper, Science and research centre of Koper; Ljubljana: University of Ljubljana, Faculty of Education. Škof, B., Cecic Erpic, S., Zabukovec, V., & Boben, D. (2002). Pupils' attitudes toward endurance sports activities. In D. Prot, & F. Prot (Eds.), Kinesiology - new perspectives, 3rd International scientific conference (pp. 137-140), Opatija: University of Zagreb, Faculty of Kinesiology. 4. Manuscript submission The main manuscript document should be saved as a Word document and named with the first author's full name and the keyword manuscript, e.g. "Pisot_Rado_manuscript.doc". Figures should be named as "Pisot_Rado_Figure1", etc. The article should be submitted via e-mail: ¡innalcs.kincsiologiac@zrs.upr. si. Reviewing process communication will proceed via e-mail. 5. For additional information regarding article publication, please do not hesitate to contact the secretary of Annales Kinesiologiae. PUBLISHING HOUSE ANNALES ZR5 KOPER issn 2232-2620 9772232262006