No ageing-related increase in fibre type grouping in sprint-trained masters runners: A 10-year follow-up study.

BACKGROUND: Previous research suggests that an ageing-associated remodelling and loss of motor units due to motor neuron death contributes significantly to muscle weakness in old age. In histological sections, motor unit remodelling is reflected by increased fibre type grouping. While regular exercise may not attenuate the loss of motor units during ageing, it has been suggested to facilitate reinnervation resulting in larger motor units, and a higher number and larger fibre type groups in histological sections of muscles from aged individuals. METHODS: In a 10-year follow-up study, we assessed changes in the prevalence and size of fibre type groups in the vastus lateralis muscle from 34 male masters sprinters (40-85 years at start). RESULTS: Over the 10 years, there was an ageing-related reduction in performance in the 60-m sprint (P < 0.001) without significant changes in fibre type composition and fibre cross-sectional area. Neither the number of fibre type groups, defined as a fibre surrounded exclusively by fibres of the same type, nor the group size changed significantly in the 10-year period. CONCLUSIONS: These histological data show that there is limited to no significant fibre type grouping over a 10-year period in masters athletes who continued sprint run training. This observation challenges the paradigm that ageing, at least in systematically trained sprinters, is associated with motor unit remodelling.

Oldies, but goldies-preserved morphology and stability of antigenic determinants in decades-old cryosections of human m. vastus lateralis.

Fibre typing by immunohistochemistry on cryosections from human skeletal muscle biopsies is an essential tool in the diagnosis and research of muscular diseases, ageing, and responses to exercise training and disuse. Preserving a good quality in these frozen specimens can be challenging especially if they are stored for longer periods before histological processing, which is often the case in studies with a large number of test subjects and/or repeated sampling separated by multiple years. We demonstrate in this article that both, the morphology and reactivity of epitopes to myosin heavy chain isoforms and dystrophin are well preserved in up to 18-year-stored unfixed and unstained cryosections of human m. vastus lateralis (n = 241). Any variation in staining intensity between samples was unrelated to the age of the biopsy donor or the storage period of the unstained cryosections, and in all cases, the obtained images were appropriate for image analysis, such as the determination of the fibre type composition and the fibre cross-sectional area, and quantitative analysis of muscle capillarisation.

Body composition in male lifelong trained strength, sprint and endurance athletes and healthy age-matched controls.

Introduction: Aging involves many physiological processes that lead to decreases in muscle mass and increases in fat mass. While regular exercise can counteract such negative body composition outcomes, masters athletes maintain high levels of exercise throughout their lives. This provides a unique model to assess the impact of inherent aging. The present study compared lean mass and fat mass in young and masters athletes from different sports to age-matched non-athletic individuals. Methods: Participants included young (20-39 years, n = 109) and older (70-89 years, n = 147) competitive male athletes, and 147 healthy age-matched controls (young = 53, older = 94 males). Athletes were separated into strength (e.g., weightlifters, powerlifters), sprint (e.g., sprint runners, jumpers) and endurance (e.g., long-distance runners, cross-country skiers) athletic disciplines. Body composition was assessed by dual-energy x-ray absorptiometry (DXA). Upper and lower limb lean mass was combined for appendicular lean mass as well as appendicular lean mass index (ALMI; kg/m2). Individuals' scores were assessed against established cut-offs for low muscle mass, obesity, and sarcopenic obesity to determine prevalence in each group. Results: ALMI was greater in young strength (0.81-2.36 kg/m2, ∼15% and 1.24-2.74 kg/m2, ∼19%) and sprint (95% CI = 0.51-1.61 kg/m2, ∼11% and 0.96-1.97 kg/m2, ∼15%) athletes than in endurance and controls, respectively (all P < 0.001). In masters athletes, only strength athletes had greater ALMI than endurance athletes, but both older strength and sprint athletes had greater ALMI than older controls (0.42-1.27 kg/m2, ∼9% and 0.73-1.67 kg/m2, ∼13%, respectively, both P < 0.001). Fat mass was significantly lower in sprint and endurance athletes compared to strength athletes and controls in both age-groups. Sarcopenic obesity was identified in one young (2%) and eighteen (19%) older controls, while only two older endurance athletes (3%) and one older strength athlete (2%) were identified. Discussion: Lifelong competitive sport participation leads to lower prevalence of sarcopenic obesity than a recreationally active lifestyle. This is achieved in strength athletes by emphasizing muscle mass, while sprint and endurance athletes demonstrate low fat mass levels. However, all older athlete groups showed higher fat mass than the young groups, suggesting that exercise alone may not be sufficient to manage fat mass.

Motives for competitive sports participation in masters track and field athletes: Impact of sociodemographic factors and competitive background.

OBJECTIVES: Masters athletes due to their lifelong engagement in sport represent a unique group to study motivation for regular physical activity, but there is less scientific data on the sport motives in masters athletes. Therefore, the aim of this study was to evaluate the association of age, sex, education, nationality, competitive background and training amount with sport motives of masters track and field athletes. METHODS: 811 (254 women) athletes aged 35-89 years participated in European Veterans Athletics Championships in the year of 2000. Sport motives were assessed with a questionnaire and categorized into1) well-being, 2) competitive and performance 3) health and fitness motives. RESULTS: Men considered health and fitness motives more important than women (p = 0.022). Over 65-year-old athletes considered health and fitness motives more important than the youngest, 35-49-year age group (p<0.001). Education was not associated with sport motives, while motives varied significantly among different nationalities. Athletes from Nordic Countries considered well-being motives more important than Southern Europeans (p<0.001) or Western Europeans (p<0.05). Athletes from Nordic Countries (p = 0.003), Eastern Europe (p<0.001) and Central Europe (p<0.001) found health and fitness motives more meaningful than athletes from the British Isles. Furthermore, athletes with competitive background before the age of 35 and training amount more than 7.5 h a week found competitive and performance motives more important than athletes without a competitive history (p = 0.002). CONCLUSIONS: These results suggest that age, sex, nationality and former athleticism are associated with sports motives among international level masters track and field athletes. It seems that while for masters athletes with competitive background performance motives dominate, for older adults, particularly for males, health and fitness motives are more important. In addition, when designing the exercise interventions for older adults, different sport motives across countries should be considered.

Longitudinal Associations of High-Volume and Vigorous-Intensity Exercise With Hip Fracture Risk in Men.

Maintenance of vigorous exercise habits from young to old age is considered protective against hip fractures, but data on fracture risk in lifelong vigorous exercisers are lacking. This longitudinal cohort study examined the hazard of hip fractures in 1844 male former athletes and 1216 population controls and in relation to exercise volume and intensity in later years. Incident hip fractures after age 50 years were identified from hospital discharge register from 1972 to 2015. Exercise and covariate information was obtained from questionnaires administered in 1985, 1995, 2001, and 2008. Analyses were conducted using extended proportional hazards regression model for time-dependent exposures and effects. During the mean ± SD follow-up of 21.6 ± 10.3 years, 62 (3.4%) athletes and 38 (3.1%) controls sustained a hip fracture. Adjusted hazard ratio (HR) indicated no statistically significant difference between athletes and controls (0.84; 95% confidence interval [CI], 0.55-1.29). In subgroup analyses, adjusted HRs for athletes with recent high (≥15 metabolic equivalent hours [MET-h]/week) and low (<15 MET-h/week) exercise volume were 0.83 (95% CI, 0.46-1.48) and 1.04 (95% CI, 0.57-1.87), respectively, compared with controls. The adjusted HR was not statistically significant between athletes with low-intensity exercise (<6 METs) and controls (1.08; 95% CI, 0.62-1.85). Athletes engaging in vigorous-intensity exercise (≥6 METs at least 75 minutes/week) had initially 77% lower hazard rate (adjusted HR 0.23; 95% CI, 0.06-0.86) than controls. However, the HR was time-dependent (adjusted HR 1.04; 95% CI, 1.01-1.07); by age 75 years the HRs for the athletes with vigorous-intensity exercise reached the level of the controls, but after 85 years the HRs for these athletes increased approximately 1.3-fold annually relative to the controls. In conclusion, these data suggest that continuation of vigorous-intensity exercise is associated with lower HR of hip fracture up to old age. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Telomere Length, SIRT1, and Insulin in Male Master Athletes: The Path to Healthy Longevity?

Lower SIRT1 and insulin resistance are associated with accelerated telomere shortening. This study investigated whether the lifestyle of master athletes can attenuate these age-related changes and thereby slow aging. We compared insulin, SIRT1, and telomere length in highly trained male master athletes (n=52; aged 49.9±7.2 yrs) and age-matched non-athletes (n=19; aged 47.3±8.9 yrs). This is a cross-sectional study, in which all data were collected in one visit. Overnight fasted SIRT1 and insulin levels in whole blood were assessed using commercial kits. Relative telomere length was determined in leukocytes through qPCR analyses. Master athletes had higher SIRT1, lower insulin, and longer telomere length than age-matched non-athletes (p<0.05 for all). Insulin was inversely associated with SIRT1 (r=-0.38; p=0.001). Telomere length correlated positively with SIRT1 (r=0.65; p=0.001), whereas telomere length and insulin were not correlated (r=0.03; p=0.87). In conclusion, master athletes have higher SIRT1, lower insulin, and longer telomeres than age-matched non-athletes. Furthermore, SIRT1 was negatively associated with insulin and positively associated with telomere length. These findings suggest that in this sample of middle-aged participants reduced insulin, increased SIRT1 activity, and attenuation of biological aging are connected.

Age-Related Declines in Lower Limb Muscle Function are Similar in Power and Endurance Athletes of Both Sexes: A Longitudinal Study of Master Athletes.

The age-related decline in muscle function, particularly muscle power, is associated with increased risk of important clinical outcomes. Physical activity is an important determinant of muscle function, and different types of physical activity e.g. power-based versus endurance-based exercise appear to have differential effects on muscle power. Cross-sectional studies suggest that participation in power-based exercise is associated with greater muscle power across adulthood but this has not been investigated longitudinally. We recruited eighty-nine male and female power and endurance master athletes (sprint and distance runners respectively, baseline age 35-90y). Using jumping mechanography, we measured lower limb muscle function during a vertical jump including at least two testing sessions longitudinally over 4.5 ± 2.4y. We examined effects of time, discipline (power/endurance) and sex in addition to two- and three-way interactions using linear mixed-effects models. Peak relative power, relative force and jump height, but not Esslingen Fitness Index (indicating peak power relative to sex and age-matched reference data) declined with time. Peak power, force, height and EFI were greater in power than endurance athletes. There were no sex, discipline or sex*discipline interactions with time for any variable, suggesting that changes were similar over time for athletes of both sexes and disciplines. Advantages in lower limb muscle function in power athletes were maintained with time, in line with previous cross-sectional studies. These results suggest that improvements in lower limb function in less active older individuals following power-based training persist with continued adherence, although this requires further investigation in interventional studies.

Regular Strength and Sprint Training Counteracts Bone Aging: A 10-Year Follow-Up in Male Masters Athletes.

Cross-sectional and interventional studies suggest that high-intensity strength and impact-type training provide a powerful osteogenic stimulus even in old age. However, longitudinal evidence on the ability of high-intensity training to attenuate age-related bone deterioration is currently lacking. This follow-up study assessed the role of continued strength and sprint training on bone aging in 40- to 85-year-old male sprinters (n = 69) with a long-term training background. Peripheral quantitative computed tomography (pQCT)-derived bone structural, strength, and densitometric parameters of the distal tibia and tibia midshaft were assessed at baseline and 10 years later. The groups of well-trained (actively competing, sprint training including strength training ≥2 times/week; n = 36) and less-trained (<2 times/week, no strength training, switched to endurance training; n = 33) athletes were formed according to self-reports at follow-up. Longitudinal changes in bone traits in the two groups were examined using linear mixed models. Over the 10-year period, group-by-time interactions were found for distal tibia total bone mineral content (BMC), trabecular volumetric bone mineral density (vBMD), and compressive strength index, and for mid-tibia cortical cross-sectional area, medullary area, total BMC, and BMC at the anterior and posterior sites (polar mass distribution analysis) (p < 0.05). These interactions reflected maintained (distal tibia) or improved (mid-tibia) bone properties in the well-trained and decreased bone properties in the less-trained athletes over the 10-year period. Depending on the bone variable, the difference in change in favor of the well-trained group ranged from 2% to 5%. The greatest differences were found in distal tibia trabecular vBMD and mid-tibia posterior BMC, which remained significant (p < 0.05) after adjustment for multiple testing. In conclusion, our longitudinal findings indicate that continued strength and sprint training is associated with maintained or even improved tibial properties in middle-aged and older male sprint athletes, suggesting that regular, intensive exercise counteracts bone aging. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Relationship between inflammatory biomarkers and testosterone levels in male master athletes and non-athletes.

BACKGROUND: Aging is often associated with low-grade systemic inflammation and reduced anabolic hormone levels. To investigate whether lifelong exercise training can decrease the age-related low-grade inflammation and anabolic hormone levels, we examined hormonal and inflammatory parameters among highly-trained male masters athletes and age-matched non-athletes. METHODS: From 70 elite power and endurance master athletes - EMA (51.3 ± 8.0 yr), 32 young controls - YC (23.7 ± 3.9 yr) and 24 untrained age-matched controls - MAC (47.2 ± 8.0 yr) venous blood was drawn to measure inflammatory parameters (interleukin-6 [IL-6], tumor necrosis factor-α [TNF-α] and interleukin-10 [IL-10]) and circulating hormones (luteinizing hormone [LH], total testosterone, estradiol, sex hormone-binding globulin [SHBG] and free androgen index [FAI]). RESULTS: EMA showed a better anti-inflammatory status than MAC (higher IL-10 and IL-10/IL-6 ratio and lower IL-6), but a lower anti-inflammatory status than YC (higher TNF-α) (p < 0.05). The MAC group had lower testosterone levels compared to the YC and EMA group (p < 0.05), and lower estradiol levels and testosterone/LH ratio compared to YC (p < 0.05). In the control groups (MAC and YC), testosterone correlated negatively with age and proinflammatory parameters, and positively with anti-inflammatory parameters. CONCLUSION: Elite master athletics elevated levels of anti-inflammatory cytokines above that seen in non-athlete peers and mitigated the age-related reduction in testosterone levels.

Absence of an aging-related increase in fiber type grouping in athletes and non-athletes.

The aging-related loss of muscle mass is thought to be partly attributable to motor neuron loss and motor unit remodeling that result in fiber type grouping. We examined fiber type grouping in 19- to 85-year-old athletes and non-athletes and evaluated to which extent any observed grouping is explained by the fiber type composition of the muscle. Since regular physical activity may stimulate reinnervation, we hypothesized that fiber groups are larger in master athletes than in age-matched non-athletes. Fiber type grouping was assessed in m. vastus lateralis biopsies from 22 young (19-27 years) and 35 healthy older (66-82 years) non-athletes, and 14 young (20-29 years), 51 middle-aged (38-65 years), and 31 older (66-85 years) athletes. An "enclosed fiber" was any muscle fiber of a particular type surrounded by fibers of the same type only. A fiber type group was defined as a group of fibers with at least one enclosed fiber. Only type II fiber cross-sectional area (FCSA) showed an age-related decline that was greater in athletes (P < .001) than in non-athletes (P = .012). There was no significant age-related effect on fiber group size or fiber group number in athletes or non-athletes, and the observed grouping was similar to that expected from the fiber type composition. At face value, these observations do 1) neither show evidence for an age-related loss and remodeling of motor units nor 2) improved reinnervation with regular physical activity, but 3) histological examination may not reveal the full extent of aging-related motor unit remodeling.

Sprint and endurance training in relation to redox balance, inflammatory status and biomarkers of aging in master athletes.

PURPOSE: Studies have shown a positive influence of intense athletic training on several biomarkers of aging, but it remains unclear whether this influence is dependent of exercise-training-mode. This study compared redox balance, cytokine levels and biomarkers of aging between master sprinters and endurance athletes, as well as in young and middle-aged individuals as controls. METHODS: Participants were male master sprinters (SA, 50 ± 8.9yrs; n = 13) and endurance runners (EA, 53 ± 8.2yrs; n = 18) with remarkable athletic experience (~25yrs of practice), besides untrained young (YC, 22.7 ± 3.9yrs; n = 17) and age-matched controls (MC, 45.5 ± 9.8yrs; n = 12). Anamnesis, anthropometrics, biomarkers of aging, inflammation status and oxidative stress parameters were analyzed in all participants. RESULTS: An increased pro-oxidant activity (elevated protein carbonyl; isoprostanes and 8-OHdG) was observed for MC in comparison to remaining groups (p < 0.05). However, SA presented a better antioxidant capacity than both MC and EA, while nitrite/nitrate (NOx) availability was higher for EA and lower for the MC (p < 0.05). Both groups of athletes presented a better anti-inflammatory status than MC (increased IL-10 and lowered IL-6, sIL-6R, sTNF-RI), but worse than YC (increased TNF-α, sTNF-RI, and sIL-6R) (p < 0.05). Telomere length was shorter in MC, which also had lower levels of irisin and klotho, and elevated FGF-23 (p < 0.05). ADMA levels were higher in MC and SA, while irisin was lower in EA when compared to SA and YC (p < 0.05). CONCLUSION: Master athletes presented better redox balance and inflammatory status, with decreased biomarkers of aging compared to control. Regarding exercise mode, a better NO- profile, as a marker of endothelial function, was observed for EA, whereas SA had a better redox balance, cytokines profile and attenuated biomarkers of aging.

Greater maintenance of bone mineral content in male than female athletes and in sprinting and jumping than endurance athletes: a longitudinal study of bone strength in elite masters athletes.

We investigated longitudinal changes in tibia bone strength in master power (jumping and sprinting) and endurance (distance) athletes of both sexes. Bone mass but not cross-sectional moment of inertia was better maintained in power than endurance athletes over time, particularly in men and independent of changes in performance. OBJECTIVE: Assessment of effects of sex and athletic discipline (lower limb power events, e.g. sprint running and jumping versus endurance running events) on longitudinal changes in bone strength in masters athletes. METHODS: We examined tibia and fibula bone properties at distal (4% distal-proximal tibia length) and proximal (66% length) sites using peripheral quantitative computed tomography (pQCT) in seventy-one track and field masters athletes (30 male, 41 female, age at baseline 57.0 ± 12.2 years) in a longitudinal cohort study that included at least two testing sessions over a mean period of 4.2 ± 3.1 years. Effects of time, as well as time × sex and time × discipline interactions on bone parameters and calf muscle cross-sectional area (CSA), were examined. RESULTS: Effects of time were sex and discipline-dependent, even following adjustment for enrolment age, sex and changes in muscle CSA and athletic performance. Male sex and participation in power events was associated with better maintenance of tibia bone mineral content (BMC, an indicator of bone compressive strength) at 4% and 66% sites. In contrast, there was no strong evidence of sex or discipline effects on cross-sectional moment of inertia (CSMI, an indicator of bone bending and torsional strength-P > 0.3 for interactions). Similar sex and discipline-specific changes were also observed in the fibula. CONCLUSIONS: Results suggest that male athletes and those participating in lower limb power-based rather than endurance-based disciplines have better maintenance of bone compressive but not bending and torsional strength.

Sprint and Strength Training Modulates Autophagy and Proteostasis in Aging Sprinters.

PURPOSE: Exercise and aging may modulate muscle protein homeostasis and autophagy, but few studies examine highly trained middle-age or older individuals. This study elucidated the effects of a new long-term training stimulus on markers of muscle autophagy and unfolded protein response (UPR) and on sprint running performance in masters sprinters. METHODS: Thirty-two male competitive sprinters (age 40-76 yr) were randomly divided into experimental (EX) and control (CTRL) groups. The EX training program was a combination of heavy and explosive strength and sprint exercises aimed at improving sprint performance. Fifteen and thirteen participants completed the 20-wk intervention period in EX and CTRL, respectively. The latter were told to continue their routine exercises. Key protein markers were analyzed by Western blotting from vastus lateralis (VL) muscle biopsies. The muscle thickness of VL was analyzed by ultrasonography and sprint performance by a 60-m running test. RESULTS: EX induced improvement in 60-m sprint performance when compared with controls (time-group, P = 0.003) without changes in VL muscle thickness. Content of lipidated microtubule-associated protein 1A/1B-light chain 3 (LC3-II) increased in EX (P = 0.022), suggesting increased autophagosome content. In addition, an autophagosome clearance marker sequestosome 1 (p62) decreased in EX (P = 0.006). Markers of UPR selectively modulated with decreases (e.g., ATF4, P = 0.003) and increases (e.g., EIF2α, P = 0.019) observed in EX. CONCLUSIONS: These findings suggest that a new intensive training stimulus that combines strength training with sprint training may increase muscle autophagosome content in a basal state without any evidence of impaired autophagosome clearance in masters sprinters. Simultaneously, the combined training may have a selective effect on the content of UPR signaling components.

Ankle and knee extensor muscle effort during locomotion in young and older athletes: Implications for understanding age-related locomotor decline.

Age-related reduction in muscle force generation capacity is similarly evident across different lower limb muscle groups, yet decline in locomotor performance with age has been shown to depend primarily on reduced ankle extensor muscle function. To better understand why ageing has the largest detrimental effect on ankle joint function during locomotion, we examined maximal ankle and knee extensor force development during a two-leg hopping test in older and young men, and used these forces as a reference to calculate relative operating efforts for the knee and ankle extensors as participants walked, ran and sprinted. We found that, across locomotion modes in both age groups, ankle extensors operated at a greater relative effort compared to knee extensors; however, slightly less pronounced differences between ankle and knee extensor muscle efforts were present among older men, mainly due to a reduction in the ankle extensor force generation during locomotion modes. We consider these findings as evidence that reduced ankle push-off function in older age is driven by a tendency to keep ankle extensor effort during locomotion lower than it would otherwise be, which, in turn, may be an important self-optimisation strategy to prevent locomotor-induced fatigue of ankle extensor muscles.

Similar relative decline in aerobic and anaerobic power with age in endurance and power master athletes of both sexes.

Lower physical activity levels in old age are thought to contribute to the age-related decline in peak aerobic and anaerobic power. Master athletes maintain high levels of physical activity with advancing age and endurance or power training may influence the extent to which these physical functions decline with advancing age. To investigate, 37-90-year-old power (n = 20, 45% female) and endurance (n = 19, 58% female) master athletes were recruited. Maximal aerobic power was assessed when cycling two-legged (VO2 Peak2-leg ) and cycling one-legged (VO2 Peak1-leg ), while peak jumping (anaerobic) power was assessed by a countermovement jump. Men and women had a similar VO2 Peak2-leg (mL/kg/min, P = 0.138) and similar ratio of VO2 Peak1-leg to VO2 Peak2-leg (P = 0.959) and similar ratio of peak aerobic to anaerobic power (P = 0.261). The VO2 Peak2-leg (mL/kg/min) was 17% (P = 0.022) and the peak rate of fat oxidation (FATmax) during steady-state cycling was 45% higher in endurance than power athletes (P = 0.001). The anaerobic power was 33% higher in power than endurance athletes (P = 0.022). The VO2 Peak1-leg :VO2 Peak2-leg ratio did not differ significantly between disciplines, but the aerobic to anaerobic power ratio was 40% higher in endurance than power athletes (P = 0.002). Anaerobic power, VO2 Peak2-leg , VO2 Peak1-leg , and power at FATmax decreased by around 7%-14% per decade in male and female power and endurance athletes. The cross-sectional data from 37-90-year-old master athletes in the present study indicate that peak anaerobic and aerobic power decline by around 7%-14% per decade and this does not differ between athletic disciplines or sexes.

Effects of Combined Strength and Sprint Training on Lean Mass, Strength, Power, and Sprint Performance in Masters Road Cyclists.

Del Vecchio, L, Stanton, R, Reaburn, P, Macgregor, C, Meerkin, J, Villegas, J, and Korhonen, MT. Effects of combined strength and sprint training on lean mass, strength, power, and sprint performance in masters road cyclists. J Strength Cond Res 33(1): 66-79, 2019-Strength and sprint-training exercises are integral part of training in many younger endurance cyclists to improve cycling efficiency and sprinting ability. This study was undertaken to examine whether muscle and performance characteristics could be improved in endurance-trained masters cyclist by adding strength and sprint-training stimuli into their training regimen. Twenty-five masters road cyclists were assigned to a combined strength and sprint-training group (CT; n = 9, 53.5 ± 9.3 years), a sprint-training group (ST, n = 7, 49.4 ± 4.8 years) or a control group (CG, n = 9, 56.9 ± 8.6 years). Before and after the 12 weeks intervention, whole body lean mass, total lower limb lean mass (LLLM), countermovement jump height, peak isometric torque of quadriceps and hamstring muscles were examined. For evaluation of sport-specific performance, 10-second sprint cycling peak power (PP10), total 30 seconds work (TW), PP output and flying 200-m time trial (TT) performance were assessed. No pretraining differences were observed between CT, ST, and CG groups for any of the dependant variables. After training, a significant (p < 0.05) between group difference was observed in TW between CT and CG groups. A significant effect of time (p < 0.05) was observed for LLLM in CT and ST groups, and for TT in the CT group. These results suggest including strength and sprint exercises in training can increase LLLM and sprint performance in endurance-trained masters road cyclists. Further research is warranted to find out an ideal pattern of training to maintain aerobic capabilities along with sprint performance in aging road cyclists.

Declining Physical Performance Associates with Serum FasL, miR-21, and miR-146a in Aging Sprinters.

Aging is associated with systemic inflammation and cellular apoptosis accelerating physiological dysfunctions. Whether physically active way of life affects these associations is unclear. This study measured the levels of serum inflammatory and apoptotic molecules, their change over 10 years, and their associations with physical performance in sprint-trained male athletes. HsCRP, cell counts, HGB, FasL, miR-21, and miR-146a were measured cross-sectionally (n = 67, 18-90 yrs) and serum FasL, miR-21, and miR-146a and their aging-related associations with physical performance were assessed over a 10-year follow-up (n = 49, 50-90 yrs). The cross-sectional study showed positive age correlations for neutrophils and negative for lymphocytes, red blood cells, HGB, FasL, and miR-146a. During the 10-year follow-up, FasL decreased (P = 0.017) and miR-21 (P < 0.001) and miR-146a (P = 0.005) levels increased. When combining the molecule levels, aging, and physical performance, FasL associated with countermovement jump and bench press (P < 0.001), miR-21 and miR-146a with knee flexion (P = 0.023; P < 0.001), and bench press (P = 0.004; P < 0.001) and miR-146a with sprint performance (P < 0.001). The studied serum molecules changed in an age-dependent manner and were associated with declining physical performance. They have potential as biomarkers of aging-related processes influencing the development of physiological dysfunctions. Further research is needed focusing on the origins and targets of circulating microRNAs to clarify their function in various tissues with aging.

Effect of concurrent resistance and sprint training on body composition and cardiometabolic health indicators in masters cyclists.

In older previously sedentary individuals endurance training imposes a more effective stimulus to enhance cardiometabolic health compared with resistance or sprint training. We examined the effect of replacing a portion of endurance training with combined resistance and/or sprint training and how this influences cardiometabolic health indicators in masters endurance cyclists. Twenty-seven well-trained male road cyclists (53.7±8.2 years) were allocated to a resistance and track sprint-cycling training group (RTC, n=10), an endurance and track sprint-cycling group (ETC, n=7) or a control endurance group (CTRL, n=10). Both the RTC and ETC groups completed a 12-week intervention of specific training while the CTRL group maintained their endurance training load. Lower limb lean mass (LLM), trunk fat mass (TFM), fasting blood glucose (FBG), total cholesterol (TC), triglycerides (TG), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were measured before and after the intervention period. TFM decreased for all groups (P<0.05) while LLM significantly increased for RTC and ETC groups (P<0.05). No significant between group or time effects were observed for FBG, TC, TG, SBP, or DBP. The results suggest that replacing a portion of endurance training with 12 weeks of ETC or RTC training favourably affects body composition by lowering TFM and increasing LLM without negatively affecting cardiometabolic health indicators in well-trained masters endurance cyclists.

Walking and Running Require Greater Effort from the Ankle than the Knee Extensor Muscles.

INTRODUCTION: The knee and ankle extensors as human primary antigravity muscle groups are of utmost importance in a wide range of locomotor activities. Yet, we know surprisingly little about how these muscle groups work, and specifically, how close to their maximal capacities they function across different modes and intensity of locomotion. Therefore, to advance our understanding of locomotor constraints, we determined and compared relative operating efforts of the knee and ankle extensors during walking, running, and sprinting. METHODS: Using an inverse dynamics biomechanical analysis, the muscle forces of the knee and ankle extensors during walking (1.6 m·s), running (4.1 m·s), and sprinting (9.3 m·s) were quantified and then related to maximum forces of the same muscle groups obtained from a reference hopping test that permitted natural elastic limb behavior. RESULTS: During walking, the relative effort of the ankle extensors was almost two times greater compared with the knee extensors (35% ± 6% vs 19% ± 5%, P < 0.001). Changing walking to running decreased the difference in the relative effort between the extensor muscle groups, but still, the ankle extensors operated at a 25% greater level than the knee extensors (84% ± 12% vs 63% ± 17%, P < 0.05). At top speed sprinting, the ankle extensors reached their maximum operating level, whereas the knee extensors still worked well below their limits, showing a 25% lower relative effort compared with the ankle extensors (96% ± 11% vs 72% ± 19%, P < 0.01). CONCLUSIONS: Regardless of the mode of locomotion, humans operate at a much greater relative effort at the ankle than knee extensor muscles. As a consequence, the great demand on ankle extensors may be a key biomechanical factor limiting our locomotor ability and influencing the way we locomote and adapt to accommodate compromised neuromuscular system function.