ArticleLiterature Review

The Effect of Aging on Skeletal-Muscle Recovery from Exercise: Possible Implications for Aging Athletes

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Abstract

Recovery from exercise is integral to the physical training process. There is a perception among older athletes that aging negatively affects the recovery process. Plausible arguments for an impaired recovery with aging are a greater susceptibility of older muscle to exercise-induced skeletal-muscle damage and a slower repair and adaptation response. Differences in the physical activity level of the research participants are rarely considered, however. This makes it difficult to differentiate the respective roles of declining physical activity and aging on the recovery process. Furthermore, the type of exercise used to induce damage and monitor recovery is often not indicative of a normal training stimulus for athletes. This review discusses the effects of aging on skeletal-muscle damage and recovery processes and highlights the limitations of many of these studies with respect to older athletes. Future research should use an exercise intervention representative of a normal training stimulus and take the physical activity level of the participants into account.

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... In conclusion, master athletes neither reach higher fatigue levels nor recover more slowly than the younger athletes. Furthermore, the results indicate that MMR after resistance exercise does not contribute to a faster recovery of INTRODUCTION It has been discussed that recovery processes during the days after intensive physical exercise are modified in elderly athletes (master athletes) compared to the age of peak performance (Fell and Williams, 2008). Master athletes experience either greater muscle damage, slower repair, or a combination of both effects, which can be attributed to physiological and social lifestyle changes beginning in the fourth decade of life effects (Smith and Norris, 2002;Fell and Williams, 2008). ...
... Furthermore, the results indicate that MMR after resistance exercise does not contribute to a faster recovery of INTRODUCTION It has been discussed that recovery processes during the days after intensive physical exercise are modified in elderly athletes (master athletes) compared to the age of peak performance (Fell and Williams, 2008). Master athletes experience either greater muscle damage, slower repair, or a combination of both effects, which can be attributed to physiological and social lifestyle changes beginning in the fourth decade of life effects (Smith and Norris, 2002;Fell and Williams, 2008). A deeper insight into the specificity of fatigue and recovery patterns of younger and older athletes during the days after an intensive bout of exercise is of practical interest for an appropriate training prescription. ...
... Regarding the physiological processes of aging, a reduction in muscle cross-sectional area and protein synthesis rate, a loss in type II muscle fibers and motor units, and a change in muscle contractile properties and stiffness have been shown (Feldman et al., 2002;Sinha-Hikim et al., 2002;Lavender and Nosaka, 2006;Brunner et al., 2007;Fell and Williams, 2008;Borges et al., 2016;McCormick and Vasilaki, 2018). Anabolic changes are mainly attributed to a 1-3% decline per year in circulating testosterone concentrations (1.6% in total and 2-3% in bioavailable testosterone) and a reduced testosterone response to resistance exercise beyond 35-40 years (Vingren et al., 2010). ...
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The aim of this study was to investigate whether recovery from eccentric squat exercise varies depending on age and to assess whether the use of a mixed-method recovery (MMR) consisting of cold water immersion and compression tights benefits recovery. Sixteen healthy and resistance-trained young (age, 22.1 ± 2.1 years; N = 8) and master male athletes (age, 52.4 ± 3.5 years; N = 8), who had a similar half squat 1-repetition maximum relative to body weight, completed two identical squat exercise training sessions, separated by a 2-week washout period. Training sessions were followed by either MMR or passive recovery (PR). Internal training loads [heart rate and blood lactate concentration (BLa)] were recorded during and after squat sessions. Furthermore, maximal voluntary isometric contraction (MVIC) force, countermovement jump (CMJ) height, resting twitch force of the knee extensors, serum concentration of creatine kinase (CK), muscle soreness (MS), and perceived physical performance capability (PPC) were determined before and after training as well as after 24, 48, and 72 h of recovery. A three-way mixed ANOVA revealed a significant time effect of the squat protocol on markers of fatigue and recovery (p < 0.05; decreased MVIC, CMJ, twitch force, and PPC; increased CK and MS). Age-related differences were found for BLa, MS, and PPC (higher post-exercise fatigue in younger athletes). A significant two-way interaction between recovery strategy and time of measurement was found for MS and PPC (p < 0.05; faster recovery after MMR). In three participants (two young and one master athlete), the individual results revealed a consistently positive response to MMR. In conclusion, master athletes neither reach higher fatigue levels nor recover more slowly than the younger athletes. Furthermore, the results indicate that MMR after resistance exercise does not contribute to a faster recovery of Schmidt et al. Recovery in Young and Master Athletes Frontiers in Physiology | www.frontiersin.org 2 September 2021 | Volume 12 | Article 665204 physical performance, neuromuscular function, or muscle damage, but promotes recovery of perceptual measures regardless of age.
... Hier deuten ebenfalls mehrere Studien darauf hin, dass die Erholungszeit altersabhängig ist und mit dem Alter zunimmt beziehunsgweise sich bei besser ausgebildeteter Ausdauerleistungsfähigkeit verkürzt. Aus dem Übersichtsartikel von Fell & Williams (2008) lassen sich als Mechanismen für eine beeinträchtigte Regeneration mit zunehmendem Alter eine höhere Anfälligkeit "älterer" Muskeln für trainingsinduzierte Skelettmuskelschäden oder auch langsamere Reparatur-und Anpassungsreaktionen nennen. Jedoch kritisieren die Autoren berechtigterweise, dass bei den bisherigen Studien nicht die unterschiedliche Leistungsfähigkeit zwischen jüngeren und älteren Sportlern berücksichtigt wurde und daher viele Fragen ungeklärt bleiben. ...
... Lebensjahr die maximale Ausprägung. Mit zunehmendem Alter nimmt sowohl die Skelettmuskelmasse als auch die Muskelleistung ab, sofern kein Ausdauer-oder Krafttraining durchgeführt wird (Fell & Williams, 2008 (Meltzer, 1994). Derartige Bewegungsausführungen werden durch eine optimale Rekrutierung der Typ-II-Fasern erbracht. ...
... Derzeit gibt es keine spezifischen Empfehlungen, die sich sowohl in der Belastung als auch der Regeneration von ausdauertrainierten Frauen und Männern bei einem HIIT unterscheiden. Auch ein möglicher Einfluss des kalendarischen Alters und ein damit scheinbar schlechter einhergehendes Belastungs-und Erholungsverhalten bei älteren Sportlern findet bisher keine spezifischen Handlungsempfehlungen bei einem intermittierenden Ausdauertraining Fell & Williams, 2008;Hebestreit et al., 1993). Das hat zur Folge, dass sowohl in der Trainingspraxis als auch in der Literatur bei HIIT-Programmen keine individuelle Belastungs-und Regenerationssteuerung, bezogen auf das Geschlecht, das Alter sowie auf die Leistungsfähigkeit erfolgt beziehungsweise vorgegeben wird. ...
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High-intensity interval training, characterized by repetitive short to long bouts of high-intensity exercise separated by recovery periods, represents a time-efficient training methodology for improving athlete performance. Previous research indicates that physiological and anatomical differences in men and women may result in divergences in training response. Furthermore, the state of research suggests that changes in skeletal muscle and different functional systems over the course of age may induce different responses to an exercise stimulus. In this regard, the results show that there is a sexual dimorphism in load and recovery during interval exercise. Furthermore, it was found that good trainability is possible in old age, which in turn may counteract age-related changes and their influence on load and recovery behavior.
... However, research regarding the effects of acute high-intensity interval exercise on the recovery of vagal HRV in team sport athletes of different ages is so far lacking. In their review article, Fell and Williams [7] concluded that an impaired recovery of older skeletal muscles could be the result of more severe exercise-induced skeletal muscle damage on the one hand, and of slower recovery and adaptive capabilities on the other hand. Research has also shown a delayed recovery of the maximum isometric force ( [8]; young athletes' M age = 31 years, older athletes' M age = 46 years) as well as altered twitching behavior ( [9]; young athletes' M age = 25 years, older athletes' M age = 66 years) when comparing older to young athletes with the same severity of exercise-induced skeletal muscle damage. ...
... Recovery kinetics and recovery time primarily depend on the intensity, duration, extent, and type of the preceding exertion as well as the athlete's performance capability and individual predisposition matrix [13]. Research that has addressed the recovery kinetics of various performance parameters after acute training loads has mainly compared groups of young (ages of mostly < 30 years) and older (ages of mostly > 50 years) athletes (for a review, see [7]). ...
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This study used a single bout of repeated high-intensity sprint exercise as a variable to compare the performance and recovery time of handball players within a typical age range for team sport athletes. Two test groups (U20 players, n = 12, mean age = 18 years; senior players, n = 17, mean age = 27 years) were observed during and after their performance of a high-intensity interval exercise consisting of four sets of 6 × 40 m all-out change-of-direction sprints. U20 players outperformed senior players in all sprint sets. The groups’ physiological responses and perceived exertion and stress levels were measured immediately before and after the exercise and also after 24, 48, and 72 h. Repeated measures ANOVAs revealed no interaction effects between age and measurement time points on jump height, muscle soreness, and perceived stress levels after the high-intensity interval exercise. However, the U20 athletes showed marginally, but not statistically significant lower creatine kinase (CK) values than the seniors 72 h after the exercise. The vagal heart rate variability (HRV) parameter rMSSD indicated a faster recovery for the U20 athletes compared to the senior players 24 h after the sprint intervals. Overall, the results demonstrate that repeated sprint intervals do not differently affect the physical performance ability (i.e., jump height) of U20 and senior players. Single parameters related to the players’ ability to recover, such as CK and HRV values, show some variations as a function of age. Based on this, coaches may want to consider a longer recovery period after a high-intensity exercise for senior players compared to younger ones.
... The hypertrophy response to RT is related to the activation of Sc in the early stage of training [55]. RT causes fiber hypertrophy in two ways: damged fibers regenerate as a result of the fusion with Sc [84] as it is proved by the incorporation of 3H thymidine into the nucleus of the muscle fiber [85], and via Sc activation under the basal lamina, devision and after that myosymplasts fuse with each other and form myotubes [86]. RT also causes other morphological adaptations, such as hyperplasia, changes in muscle fine architecture, in myofilament density and in the structures of connective tissue [55]. ...
... RT enhances the synthesis rate of myofibrillar proteins, not of sarcoplasmic proteins, and this is related to the mammalian target of rapamycin complex by activating proteins with mitogen activated protein kinase signalling [57]. Recovery from intensive RT caused damages is slower as a result of age, whereas there are no age related differences in recovery from less damaging metabolic fatigue [86]. Recovery from RT, during which the power of exercise increases less than 5% per session, causes hypertrophy of both FT and ST muscle fibres and an increase in the myonuclear number. ...
... Recovery from exercise is essential for continuous performance improvement [1,2]. Due to morphological and physiological changes occurring during aging and age-related alterations in performance capacity, younger and older athletes may recover at different rates from physical exercise and training loads [3][4][5]. ...
... Therefore, training adaptation, decline in performance, and recovery in the process of aging varies among different sports and intensities of exercise. According to Fell and Williams [3], an older athlete may require a more extended post-exercise recovery period compared to a younger athlete with a similar performance level when applying the same training load. The extent to which age-related physiological and morphological differences affect recovery in aging athletes during high-intensity interval training (HIIT) sessions with different recovery periods has not yet been investigated. ...
Article
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Due to physiological and morphological differences, younger and older athletes may recover differently from training loads. High-intensity interval training (HIIT) protocols are useful for studying the progression of recovery. It was the objective of this study to determine age differences in performance and recovery following different HIIT protocols. Methods: 12 younger (24.5 � 3.7 years) and 12 older (47.3 � 8.6 years) well-trained cyclists and triathletes took part in this study. Between the age groups there were no significant differences in relative peak power to fat-free mass, maximal heart rate (HR), training volume, and VO2max-percentiles (%). Participants performed different HIIT protocols consisting of 4 � 30 s Wingate tests with different active rest intervals (1, 3, or 10 min). Peak and average power, lactate, HR, respiratory exchange ratio (RER), subjective rating of perceived exertion (RPE), and recovery (Total Quality Recovery scale, TQR) were assessed. Results: During the different HIIT protocols, metabolic, cardiovascular, and subjective recovery were similar between the two groups. No significant differences were found in average lactate concentration, peak and average power, fatigue (%), %HRmax, RER, RPE, and TQR values between the groups (p > 0.05). Conclusion: The findings of this study indicate that recovery following HIIT does not differ between the two age groups. Furthermore, older and younger participants displayed similar lactate kinetics after the intermittent exercise protocols.
... However, the body of literature on this topic is limited and reveals conflicting results. [3][4][5][6] It becomes evident that postexercise recovery is a complex process that is modulated and influenced by numerous individual and external determinants. Therefore, different factors must be considered when analyzing and discussing this topic. ...
... Only the velocity at ventilatory threshold 2 was significantly lower in masters compared to adult triathletes (-8.3% vs -2.5%) 24 hours postcompetition, while muscular strength was not impaired. Easthope et al 11 No delay in recovery in 9 master cyclists (45 [6] y) compared to 9 adult (24 [5] y) cyclists in laboratory experiments was observed by Fell et al. 12,13 Both age groups with similar VO 2 max performed three 30-minute time trials with similar absolute power output on 3 consecutive days. Results for average power, lactate, countermovement jumps, sprint performance, and MVIC showed no statistically significant differences between the 2 age groups. ...
Article
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Postexercise recovery is a fundamental component for continuous performance enhancement. Due to physiological and morphological changes in aging and alterations in performance capacity, athletes of different ages may recover at different rates from physical exercise. Differences in body composition, physiological function, and exercise performance between men and women may also have a direct influence on restoration processes. Purpose: This brief review examines current research to indicate possible differences in recovery processes between male and female athletes of different age groups. The paper focuses on postexercise recovery following sprint and endurance tests and tries to identify determinants that modulate possible differences in recovery between male and female subjects of different age groups. Results: The literature analysis indicates age- and sex-dependent differences in short- and long-term recovery. Short-term recovery differs among children, adults, and masters. Children have shorter lactate half-life and a faster cardiac and respiratory recovery compared to adults. Additionally, children and masters require shorter recovery periods during interval bouts than trained adults. Trained women show a slower cardiac and respiratory recovery compared to trained men. Long-term recovery is strongly determined by the extent of muscle damage. Trained adults tend to have more extensive muscle damage compared to masters and children. Conclusion: The influence of age and sex on the recovery process varies among the different functional systems and depends on the time of the recovery processes. Irrespective of age and sex, the performance capacity of the individual determines the recovery process after high-intensity and endurance exercise.
... Since these negative effects may also decrease the frequency of training, continuance can be difficult to achieve; therefore, eliminating their influence may effectively inhibit *Correspondence: terada@sta.tenri-u.ac.jp the decrease in the training effect. Since recovery from training-induced muscle damage is influenced by aging, middle-aged and elderly subjects have a particularly high need for physical care after training 12,13) . Various types of physical therapies have been conventionally used for physical care after exercise. ...
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A randomized controlled trial was conducted to investigate the interactive influence of massage and exercise on health-related physical fitness in middle-aged and older adults. Thirty-eight healthy males aged 40 to 69 years were randomly assigned to one of three groups: an exercise and self-massage intervention group (S group, n = 13), exercise training only intervention group (T group, n = 13), or control group (C group, n = 12). Subjects in S group underwent structured manual self-massage comprising static stretching of the entire body and Oriental Medicine techniques such as manual massage and stimulation of acupuncture points (physical care). An exercise regimen for both S group and T group was comprised of groupbased and home-based training, including resistance training of upper and lower limbs and abdominal muscles, endurance training, and plyometric training for 12 weeks. The major outcome measures were the 30-second chair-stand test (CS-30), vertical jump (VJ), shoulder horizontal adduction (SHA, muscle–strength test), 30-second sit-up test (SU-30), center of foot pressure (CoP), and the chair sit-and-reach test (CSR). The S group showed significantly greater postintervention improvements (p < 0.05) in measures of CS-30 (+22%), VJ (+23%), SU-30 (+14%), locus length per unit area in CoP, with eyes closed (L/A) (-18%), and CSR (+44%). Whereas, the T group showed improvements in CS-30 (+11%), VJ (+20%), SHA (+15%), and L/A (-24%). The C group experienced no significant changes. There were no significant differences between the T and C groups. The S-group’s post-intervention CS-30 and VJ values were significantly higher than those of the C group (p < 0.05). A concurrent massage intervention (physical care) was shown to enhance exercise effects.
... It is possible that a greater effect would be seen for higher frequencies if more nonvolume equated studies were carried out in young individuals. This speculation is based on the observation that older adults seem to have impaired recovery following exercise in comparison to their younger counterparts (Fell & Williams, 2008). Given a superior ability to recover from intense exercise, young adults might conceivably respond better to greater training frequencies with a correspondingly higher training volume. ...
Article
Training frequency is considered an important variable in the hypertrophic response to regimented resistance exercise. The purpose of this paper was to conduct a systematic review and meta-analysis of experimental studies designed to investigate the effects of weekly training frequency on hypertrophic adaptations. Following a systematic search of PubMed/MEDLINE, Scoups, and SPORTDiscus databases, a total of 25 studies were deemed to meet inclusion criteria. Results showed no significant difference between higher and lower frequency on a volume-equated basis. Moreover, no significant differences were seen between frequencies of training across all categories when taking into account direct measures of growth, in those considered resistance-trained, and when segmenting into training for the upper body and lower body. Meta-regression analysis of non-volume-equated studies showed a significant effect favoring higher frequencies, although the overall difference in magnitude of effect between frequencies of 1 and 3+ days per week was modest. In conclusion, there is strong evidence that resistance training frequency does not significantly or meaningfully impact muscle hypertrophy when volume is equated. Thus, for a given training volume, individuals can choose a weekly frequency per muscle groups based on personal preference.
... They continue staying fit and strive to be healthy, but traditional fitness classes and regimes do not appeal to everyone and some look for and seek a change in these old habits. Another crucial consideration is that it is especially difficult for some of the middle/older aged individuals to continue training due to the continued demand on the body and the recognition it takes longer to recover (Fell & Williams, 2008). There is also the consideration of "mid-life crisis" when individuals start to question their reason for being and start to develop a period of lethargy around what they should do with their lives (Smith, 2018). ...
Article
This article assesses current discussions and research around the considerations of martial arts practice for older participants. This has been undertaken, as there appears to be several articles that determine there are some benefits, however this is mostly in the area of Tai Chi and its use to improve the overall wellness or well-being of elderly participants. What the article then proposes is that research in harder martial arts, as they are termed, may also be of benefit. This is due to a small amount of research in slightly older participants mid to late-thirties who find that there are a wide range of benefits above that of usual physical interventions. Using hard martial arts as an intervention or researching benefits for older participants, plus fifty five, it is thought, may prove to be a positive thing as martial arts are perceived to have wide ranging benefits for those who participate.
... Physical activity also decreases with age, due to a change in lifestyle. Somehow, the physiological changes of the muscles are aggravated by age-related neurological changes [49]. Most of the muscular activities become less efficient and less responsive with ageing as a result of a decrease in the nervous activity and nerve conduction. ...
... [20] Intensity of the recovery is of the most important factors that should be controlled according to the adverse effect of recovery caused by accumulation of substances produced through metabolism. [26] Demirhan et al. investigated the effect of immersion in cold water and ice massage after exercise in elite wrestlers. [11] They reported that there was no significant difference between the The changes of C-reactive protein among different recovery methods. ...
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Aims: One of the important issues in the context of exercise physiology is apply the best recovery methods completely after intense physical activities. Recovery methods will decrease the risk of muscle damage and subsequent inflammation. The aim of this study is to investigate the recovery procedures on changes of creatine kinase (CK) and C-reactive protein (CRP) after an exercise session simulated in professional football players. Methods: Thirty Iran's Azadegan League football players were participated in this research (age: 22.4 ± 2.38, height: 179.1 ± 2.63 cm, weight: 68.5 ± 4.82 kg, body mass index: 21.5 ± 2.10 kg/m2). After exercise protocol, simulation team randomly divided the participants into three groups (n = 10) under an active recovery on land, floating in the cold water (10°C), and passive recovery for 12 min. The levels of serum CK and CRP were collected immediately, 24 h, and 48 h after the exercise protocol. Findings: The results showed a significant decrease in CK and CRP after training in cold-water immersion method comparing to the other methods (P < 0.05). In addition, the level of CRP was significantly less than passive recovery 48 h postexercise recovery (P < 0.05). Conclusion: The finding of this study shows that if recovery in cold water was used immediately after exercise, much better results are obtained in future periods. This means that immersion method in cold water probably leads to decreased signs of muscle soreness and inflammatory responses in male football players. Keywords: Cold-water immersion, inflammatory responses, muscle damage, muscle enzymes, muscle soreness, recovery methods
... Much of a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 the research into exercise recovery is focused around the impact of peripheral alterations, while the influence of central factors demands further study [10,11]. Understanding the underlying mechanisms behind the recovery process can have particularly valuable implications among groups known to suffer from impaired recovery, such as elderly and clinical populations [12,13]. ...
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Exercise-induced muscle damage (EIMD) is associated with impaired muscle function and reduced neuromuscular recruitment. However, motor unit firing behaviour throughout the recovery period is unclear. EIMD impairment of maximal voluntary force (MVC) will, in part, be caused by reduced high-threshold motor unit firing, which will subsequently increase to recover MVC. Fourteen healthy active males completed a bout of eccentric exercise on the knee extensors, with measurements of MVC, rate of torque development and surface electromyography performed pre-exercise and 2, 3, 7 and 14 days post-exercise, on both damaged and control limb. EIMD was associated with decreased MVC (235.2 ± 49.3 Nm vs. 161.3 ± 52.5 Nm; p <0.001) and rate of torque development (495.7 ± 136.9 Nm.s-1 vs. 163.4 ± 163.7 Nm.s-1; p <0.001) 48h post-exercise. Mean motor unit firing rate was reduced (16.4 ± 2.2 Hz vs. 12.6 ± 1.7 Hz; p <0.01) in high-threshold motor units only, 48h post-exercise, and common drive was elevated (0.36 ± 0.027 vs. 0.56 ± 0.032; p< 0.001) 48h post-exercise. The firing rate of high-threshold motor units was reduced in parallel with impaired muscle function, whilst early recruited motor units remained unaltered. Common drive of motor units increased in offset to the firing rate impairment. These alterations correlated with the recovery of force decrement, but not of pain elevation. This study provides fresh insight into the central mechanisms associated with EIMD recovery, relative to muscle function. These findings may in turn lead to development of novel management and preventative procedures.
... An age consequence is a slower recovery from RT damaging, whereas recovery from small damaging metabolic fatigue did not report age-related difference [46]. RT increased the level of insulin-like growth factor 1 (IGF-1) and of mechano growth factor (MGF) in skeletal muscle and faster recovery of muscle tissue is supported by both these elements [47]. ...
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Skeletal muscle is a dynamic tissue with remarkable plasticity and its growth and regeneration are highly organized, with the activation of specific transcription factors, proliferative pathways and cytokines. The decline of skeletal muscle tissue with age, is one of the most important causes of functional loss of independence in older adults. Maintaining skeletal muscle function throughout the lifespan is a prerequisite for good health and independent living. Physical activity represents one of the most effective preventive agents for muscle decay in aging. Several studies have underlined the importance of microRNAs (miRNAs) in the control of myogenesis and of skeletal muscle regeneration and function. In this review, we reported an overview and recent advances about the role of miRNAs expressed in the skeletal muscle, miRNAs regulation by exercise in skeletal muscle, the consequences of different physical exercise training modalities in the skeletal muscle miRNA profile, their regulation under pathological conditions and the role of miRNAs in age-related muscle wasting. Specific miRNAs appear to be involved in response to different types of exercise and therefore to play an important role in muscle fiber identity and myofiber gene expression in adults and elder population. Understanding the roles and regulation of skeletal muscle miRNAs during muscle regeneration may result in new therapeutic approaches in aging or diseases with impaired muscle function or re-growth.
... The in vivo parallel to the myoblast scratch assay we report here is most likely muscular injury and recovery. In this light, it is interesting to note that older individuals show anabolic resistance to amino acid feeding (Cuthbertson et al., 2005), reduced rates of satellite cells per muscle fibre (Verdijk et al., 2007), and reduced muscle recovery following immobilisation-retraining (Suetta et al., 2009), ultimately resulting in a proposed reduced rate of injury repair and recovery (Fell and Williams, 2008) and increased intermuscular fibrosis and adipose tissue, and a reduced muscle force output (Alnaqeeb et al., 1984;Delmonico et al., 2009). Whilst speculative at this point, the endocrine mechanistic reduction in scratch-recovery in our in vitro older condition may in part reflect the early stages of this process. ...
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Ageing is associated with a general reduction of physiological function and a reduction of muscle mass and strength. Endocrine factors such as myostatin, activin A, growth and differentiation factor 11 (GDF-11) and their inhibitory peptides influence muscle mass in health and disease. We hypothesised that myocytes cultured in plasma from older and younger individuals would show an ageing effect, with reduced proliferation and differentiation in older environments. C2C12 myoblasts were grown as standard and stimulated with media conditioned with 5% plasma from healthy male participants that were either younger (n = 6, 18–35 years of age) or older (n = 6, >57 years of age). Concentration of plasma myostatin (total and free), follistatin-like binding protein (FLRG), GDF-11 and activin A were quantified by ELISA. Both FLRG and activin A were elevated in older individuals (109.6 and 35.1% increase, respectively), whilst myostatin (free and total) and GDF-11 were not. Results indicated that plasma activin A and FLRG were increased in older vs. younger participants, GDF11 and myostatin did not differ. Myoblasts in vitro showed no difference in proliferation rate between ages, however scratch closure was greater in younger vs. older plasma stimulated myoblasts (78.2 vs. 87.2% of baseline scratch diameter, respectively). Myotube diameters were larger in cells stimulated with younger plasma than with older at 24 and 48 h, but not at 2 h. A significant negative correlation was noted between in vivo plasma FLRG concentration and in vitro myotube diameter 48 h following plasma stimulation (r2 = 0.392, p = 0.030). Here we show that myoblasts and myotubes cultured in media conditioned with plasma from younger or older individuals show an ageing effect, and further this effect moderately correlates with circulating FLRG concentration in vivo. The effect of ageing on muscle function may not be innate to the tissue, but involve a general cellular environment change. Further work is needed to examine the effect of increased FLRG concentration on muscle function in ageing populations.
... In addition, previous studies showed that lifelong chronic physical activity can reduce chronic inflammation and improve immune and muscle functions (Minuzzi et al., 2019;Lavin et al., 2020). Studies that have compared the recovery rates between younger and middle-aged or older (>50y) trained individuals following resistance exercise protocols, found that the decline in recovery rates begin at~40 years of age (Korhonen et al., 2006;Fell and Williams, 2008;Gordon et al., 2017). For example, a comparison in recovery rates between younger and older sedentary adults following an eccentric resistance exercise protocol, found that the older adults suffer from higher rates of eccentric-induced muscle dysfunction (Ploutz-Snyder et al., 2001). ...
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Purpose: Compare recovery rates between active young (Y) and middle-aged (MA) males up to 48H post aerobically based, exercise-induced muscle damage (EIMD) protocol. A secondary aim was to explore the relationships between changes in indices associated with EIMD and recovery throughout this timeframe. Methods: Twenty-eight Y ( n = 14, 26.1 ± 2.9y, 74.5 ± 9.3 kg) and MA ( n = 14, 43.6 ± 4.1y, 77.3 ± 12.9 kg) physically active males, completed a 60-min downhill running (DHR) on a treadmill at −10% incline and at 65% of maximal heart rate (HR). Biochemical, biomechanical, psychological, force production and muscle integrity (using MRI diffusion tensor imaging) markers were measured at baseline, immediately-post, and up to 48H post DHR. Results: During the DHR, HR was lower ( p < 0.05) in MA compared to Y, but running pace and distance covered were comparable between groups. No statistical or meaningful differences were observed between groups for any of the outcomes. Yet, Significant ( p < 0.05) time-effects within each group were observed: markers of muscle damage, cadence and perception of pain increased, while TNF-a, isometric and dynamic force production and stride-length decreased. Creatine-kinase at 24H-post and 48H-post were correlated ( p < 0.05, r range = −0.57 to 0.55) with pain perception, stride-length, and cadence at 24H-post and 48H-post. Significant ( p < 0.05) correlations were observed between isometric force production at all time-points and IL-6 at 48H-post DHR ( r range = −0.62 to (−0.74). Conclusion: Y and MA active male amateur athletes recover in a comparable manner following an EIMD downhill protocol. These results indicate that similar recovery strategies can be used by trainees from both age groups following an aerobic-based EIMD protocol.
... Indeed, recent studies show that age-related impairments in whole-body heat loss result in greater body heat storage in middle-age and older adults (940 yr) compared with young adults (18-30 yr) during exercise in both dry and humid heat (39,40). It is also likely that older adults, who are known to recover and regenerate from exercise-induced stress more slowly than young individuals (41), may recover more slowly from prolonged work in the heat and therefore accumulate a higher level of physiological strain over consecutive work shifts. Given the rising number of older adults in the workforce (42), future studies are required to determine whether heat loss capacity is impaired in these individuals on the day after prolonged work in the heat. ...
Article
Purpose: Heat strain is known to be exacerbated on the second of consecutive work days. We therefore evaluated whether prolonged work in the heat would impair whole-body heat loss capacity on the next day. Methods: To evaluate this possibility, we assessed changes in whole-body heat exchange and heat storage in eight young (26 years (SD 4)) males during heat stress tests performed on the same day prior to (Day 1), and on the day following (Day 2), a prolonged work simulation. Each heat stress test involved three, 30-min bouts of semi-recumbent cycling at fixed rates of metabolic heat production (200 (Ex1), 250 (Ex2) and 300 Wm (Ex3)), each separated by 15-min recovery, in hot-dry conditions (40°C, 20% relative humidity). The work simulation (7.5 h) involved three moderate intensity intermittent work bouts (2 h), each separated by 30-min rest breaks, under similarly hot-dry conditions (38°C, 34% relative humidity). Total heat loss (evaporative ± dry heat exchange) and metabolic heat production were measured using direct and indirect calorimetry, respectively. Body heat storage was quantified as the temporal summation of heat production and loss. Results: Total heat loss did not differ between Day 1 and 2 (P=0.66), and averaged (mean±95% CI) 185±7 W (Ex1), 233±7 W (Ex2) and 261±5 W (Ex3) across test days. Consequently, the change in body heat storage was also similar between Day 1 and 2 (P=0.32), averaging 133±15 kJ (Ex1), 99±16 kJ (Ex2) and 184±15 kJ (Ex3) across test days. Conclusion: When assessed in controlled laboratory conditions in young men, prolonged work in the heat does not appear to impair whole-body heat loss nor exacerbate heat storage on the following day.
... Changes in recovery from a bout of exercise may be associated with the aging process (12). Recovery is often determined by the return of performance measures to baseline (BL) levels or by an attenuation of the inflammatory or muscle damage response to exercise (15,35). ...
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The purpose of this study was to compare the effects of a bout of high-volume isokinetic resistance exercise (HVP) on lower-body strength and markers of inflammation and muscle damage during recovery between young and middle-aged men. Nineteen recreationally-trained men were classified as either a young adult (YA: 21.8 ± 2.0 y; 90.7 ± 11.6 kg) or middle-aged adult (MA: 47.0 ± 4.4 y; 96.0 ± 21.5 kg) group. The HVP consisted of 8 sets of 10 repetitions, with one minute of rest between each set, performed on an isokinetic dynamometer at 60°·sec. Maximal voluntary isometric contractions (MVIC) and isokinetic peak (PKT) and average (AVGT) torque (measured at 240° and 60°·sec) were assessed at baseline (BL), immediately-post (IP), 120-min (120P), 24-hr (24H) and 48-hr (48H) following HVP. Blood was obtained at BL, IP, 30-min, 60-min, 120-min, 24H and 48H following HVP to assess muscle damage and inflammation. All performance data were analyzed using repeated-measures ANCOVA, while all inflammatory and muscle damage markers were analyzed using a two-way (time x group) repeated-measures ANOVA. Results revealed no between-group differences for PKT, AVGT, or rate of torque development at 200ms (RTD200). No between-group differences in myoglobin, creatine kinase, C-reactive protein, or interleukin-6 were observed. Although baseline differences in muscle performance were observed between YA and MA, no between group differences were noted in performance recovery measures from high-volume isokinetic exercise in recreationally-trained men. These results also indicate that the inflammatory and muscle damage response from high-volume isokinetic exercise is similar between recreationally-trained, young and middle-aged adult men.
... Even if there indeed was an advantage favoring the group that trained to failure in the Martorelli et al. study, it should be noted that the included participants were young women and therefore, the results cannot be generalized to older adults. Older adults might experience slower post-exercise recovery and may warrant a different approach to their program design(6). daSilva et al. (3) essentially used the same study design as Martorelli and colleagues (16) while ...
Article
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It has been proposed that training to failure is a necessary strategy to maximize muscle growth. This paper examines the research behind these claims, and attempts to draw evidence-based conclusions as to the practical implications for hypertrophy training.
... Immediate and short-term recoveries are linked to metabolic, energy sources and electrolytes regeneration, whereas training recovery is linked to structural and energy sources restoration. In the context of soccer matches or training sessions, these physiological responses are highly variable and depend on several intrinsic factors [1], but they are also influenced by extrinsic factors such as training status, age, gender and muscle fiber type [80,81]. These could explain inter-individual variability in acute fatigue or training recovery processes when comparing players from the same team. ...
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Background: Soccer presents physiological, metabolic, physical and psychological demands which can deteriorate players’ performance due to fatigue. The high variability in physiological, metabolic, physical and psychological responses also influences the magnitude of exercise-induced muscle damage, with symptoms negatively affecting neuromuscular function during recovery or subsequent training sessions or matches. Consequently, more precise and consistent knowledge is required in this area to optimize training and performance. Objective: Therefore, the purpose is to sum-up current evidence on fatigue and recovery in soccer players, to shed light on factors that can affect players’ performance, and to suggest applications for coaches and further research. Method: A comprehensive review of the scientific literature on the field was conducted. Results: Physical performance decrements during matches have traditionally been associated with physiological fatigue, but the magnitude of the symptoms in soccer players is unclear and depends on several factors. Moreover, the decline in physical performance during a soccer match is related to specific demands of each match. These could explain inter-individual variability in acute fatigue or training recovery processes when comparing players from the same team. Recovery counteracts the effects of fatigue, both peripheral and central, but there is a lack of consensus about the usefulness of tests used to monitor fatigue and recovery kinetics. Conclusion: Although fatigue and recovery in soccer has been extensively studied, there are still uncertainties about the underlying mechanisms because they are influenced by physiological and match-related demands.
... Immediate and short-term recoveries are linked to metabolic, energy sources and electrolytes regeneration, whereas training recovery is linked to structural and energy sources restoration. In the context of soccer matches or training sessions, these physiological responses are highly variable and depend on several intrinsic factors [1], but they are also influenced by extrinsic factors such as training status, age, gender and muscle fiber type [80,81]. These could explain inter-individual variability in acute fatigue or training recovery processes when comparing players from the same team. ...
Article
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Background Soccer presents physiological, metabolic, physical and psychological demands which can deteriorate players’ performance due to fatigue. The high variability in physiological, metabolic, physical and psychological responses also influences the magnitude of exercise-induced muscle damage, with symptoms negatively affecting neuromuscular function during recovery or subsequent training sessions or matches. Consequently, more precise and consistent knowledge is required in this area to optimize training and performance. Objective Therefore, the purpose is to sum-up current evidence on fatigue and recovery in soccer players, to shed light on factors that can affect players’ performance, and to suggest applications for coaches and further research. Method A comprehensive review of the scientific literature on the field was conducted. Results Physical performance decrements during matches have traditionally been associated with physiological fatigue, but the magnitude of the symptoms in soccer players is unclear and depends on several factors. Moreover, the decline in physical performance during a soccer match is related to specific demands of each match. These could explain inter-individual variability in acute fatigue or training recovery processes when comparing players from the same team. Recovery counteracts the effects of fatigue, both peripheral and central, but there is a lack of consensus about the usefulness of tests used to monitor fatigue and recovery kinetics. Conclusion Although fatigue and recovery in soccer has been extensively studied, there are still uncertainties about the underlying mechanisms because they are influenced by physiological and match-related demands.
... Together, these factors contribute to a magnitude of fatigue and muscle damage that is very variable between matches 18 . Other factors such as state of fitness, age 19 , and the type of muscle fibre 20 can explain the inter-individual differences in the fatigue-recovery process of players on the same team. ...
Article
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Training and competition provide an opportunity to enhance the performance of football players, so is essential to face every training session or competition in the best possible condition. For our knowledge, there are still doubts about the causes and mechanisms underlying fatigue and recovery in football, hence the complexity of monitoring this process. A variety of biomarkers are used nowadays (performance, perceptual and biochemical), but some may not be suitable due to the probable fatigue caused that could influence the recovery process. Despite the difficulty of obtain them in some categories where is not plausible, the information of biochemical markers should be considered whenever was possible. Since its assessment let to optimize the balance between competitive stress and recovery of football players, the aim of this review is to analyze the importance of control, monitoring and evaluate different biochemical markers of recovery in soccer players. Even so, the high variability in their response due to the individual characteristics of players and the metabolic and physiological differences caused by a soccer match or training stop us from monitoring the recovery process in soccer using only one biochemical marker, it is necessary to assess several markers together. In fact, they should be considered as an option to complement the information obtained through physical performance and perceptive markers.
... At the same time, both inflammation and oxidative stress increases with aging suggesting that the older exercising adults might require higher level of nutrients and foods with antioxidant and anti-inflammatory properties. In addition, when conducting the same type of exercise, the older persons are known to more easily suffer from muscle damage and require a longer period to recover from it (127). The exercise-induced muscle damage can initiate an inflammatory response, which could further exacerbate the chronic lowgrade inflammation observed in older adults, further suggesting that exercising older adults might require higher level of nutrients and other dietary components with immune enhancing and/or anti-inflammatory properties than non-exercising older adults or their young counterparts. ...
Article
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In this consensus statement on immunonutrition and exercise, a panel of knowledgeable contributors from across the globe provides a consensus of updated science, including the background, the aspects for which a consensus actually exists, the controversies and, when possible, suggested directions for future research.
... In this context, it is well known that strength training exercises are one of the most important interventions capable of attenuating the deleterious effects of aging in muscle tissue, improving contractile muscle properties, promoting an increase in the number and size of myofibrils, and increasing the cross-sectional area of muscle fibers [10,11]. However, some points need to be considered before the prescription of strength exercises to this population, such as the body fragility due to the increase in oxidative stress leading to higher susceptibility to injuries and fatigability [12][13][14]. ...
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The aging process leads to a gradual loss of muscle mass and muscle performance, leading to a higher functional dependence. Within this context, many studies have demonstrated the benefits of a combination of physical exercise and low level laser therapy (LLLT) as an intervention that enhances muscle performance in young people and athletes. The aim of this study was to evaluate the effects of combination of LLLT and strength training on muscle performance in elderly women. For this, a hundred elderly women were screened, and 48 met all inclusion criteria to participate in this double-blind placebo-controlled trial. Volunteers were divided in three groups: control (CG = 15), strength training associated with placebo LLLT (TG = 17), and strength training associated with active LLLT (808 nm, 100 mW, 7 J) (TLG = 16). The strength training consisted of knee flexion-extension performed with 80 % of 1-repetition maximum (1-RM) during 8 weeks. Several outcomes related to muscle performance were analyzed through the 6-min walk test (6-MWT), isokinetic dynamometry, surface electromyography (SEMG), lactate concentration, and 1-RM. The results revealed that a higher work (p = 0.0162), peak torque (p = 0.0309), and power (p = 0.0223) were observed in TLG compared to CG. Furthermore, both trained groups increased the 1-RM load (TG vs CG: p = 0.0067 and TLG vs CG: p < 0.0001) and decreased the lactate concentration in the third minute after isokinetic protocol (CG vs TLG: p = 0.0289 and CG vs TG: p = 0.0085). No difference in 6-MWT and in fatigue levels were observed among the groups. The present findings suggested that LLLT in combination with strength training was able to improve muscle performance in elderly people.
... Increase of muscle activity increases the synthesis rate of myofibrillar proteins [26] via a mammalian target of rapamycin-activating proteins within the nitrogen-activated protein kinase signaling [27]. The recovery from the last exercise session, particularly from intensive exercise, is faster in the young than in the elderly [28]. ...
Article
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Muscle weakness in corticosteroid myopathy is mainly the result of the destruction and atrophy of the myofibrillar compartment of fast-twitch muscle fibers. Decrease of titin and myosin, and the ratio of nebulin and MyHC in myopathic muscle, shows that these changes of contractile and elastic proteins are the result of increased catabolism of the abovementioned proteins in skeletal muscle. Slow regeneration of skeletal muscle is in good correlation with a decreased number of satellite cells under the basal lamina of muscle fibers. Aging causes a reduction of AMP-activated protein kinase (AMPK) activity as the result of the reduced function of the mitochondrial compartment. AMPK activity increases as a result of increased functional activity. Resistance exercise causes anabolic and anticatabolic effects in skeletal muscle: muscle fibers experience hypertrophy while higher myofibrillar proteins turn over. These changes are leading to the qualitative remodeling of muscle fibers. As a result of these changes, possible maximal muscle strength is increasing. Endurance exercise improves capillary blood supply, increases mitochondrial biogenesis and muscle oxidative capacity, and causes a faster turnover rate of sarcoplasmic proteins as well as qualitative remodeling of type I and IIA muscle fibers. The combination of resistance and endurance exercise may be the fastest way to prevent or decelerate muscle atrophy due to the anabolic and anticatabolic effects of exercise combined with an increase in oxidative capacity. The aim of the present short review is to assess the role of myofibrillar protein catabolism in the development of glucocorticoid-caused myopathy from aging and physical activity aspects.
... Thus, physical exercise programs are one of the most efficient interventions to attenuate age-related musculoskeletal tissue modifications [8]. However, the prescription of physical exercise to the population of older adults requires special considerations due to the high incidence of injuries and susceptibility to fatigue [9,10]. ...
Article
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The study assessed if quadriceps femoris muscle performance of older women can be improved by applying photobiomodulation therapy after a resistance training program. This study is a randomized, controlled trial with concealed allocation, intention-to-treat analysis, and blinded outcome evaluators. Forty-five healthy sedentary older women classified as active or insufficiently active were randomized to groups receiving 8 weeks of quadriceps femoris resistance training plus active group or placebo group, or a control group (no training or photobiomodulation). Surface electromyographic fatigue indexes of vastus medialis, rectus femoris, and vastus lateralis; one-maximum repetition (1-MR); and analysis of inflammatory biomarkers (IL-6, IL-8, and TNF-α cytokines, plus CK and LDH enzymes) were measured at baseline and twice in a 24 h-period after 8 weeks. No differences among the three groups were found in fatigue indexes for all three muscles, although in general, the active group presented improved fatigue indexes from baseline to 8-week outcome, while the other groups did not. Both training groups improved in 1-MR over the 8-week period. Inflammatory biomarkers were not different at long- or short-term among the three groups, except differences in groups for long-term IL-8 changes, differences in time for long-term LDH and short-term TNF-α changes, and interactions of time by group for short-term LDH changes. Quadriceps femoris performance of older women was not improved when photobiomodulation was associated to the proposed quadriceps femoris resistance training, when compared to training without photobiomodulation and a sedentary group.
... In contrast, the TC program will keep the intensity (gear resistance) the same, but greatly reduce the volume by 40-60% (e.g., Tuesday K-1 day having 3 3 1 single cluster set instead of 3 3 3 and by a single 200-m fly test effort on the Sunday session instead of the fly Sunday session). Periodization is especially important for master athletes, who unlike younger athletes, require increased time for recovery, after intense exercise (8,15,17). To monitor weekly training loads and to ensure excessive fatigue is prevented, the session ratings of perceived exertion (RPE) method can be used to evaluate the masters athletes' tolerance to training, by calculating and analyzing training loads over time (16). ...
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PARTICIPATION NUMBERS IN MASTERS TRACK CYCLING DEMONSTRATE THAT TRACK CYCLING IS BECOMING AN INCREASINGLY POPULAR SPORT FOR MASTERS ATHLETES. DESPITE THIS, RESEARCH FOCUSED ON PERFORMANCE ENHANCEMENT FOR MASTERS TRACK CYCLISTS IS LACKING. AGE-RELATED CHANGES IN MORPHOLOGICAL AND NEUROMUSCULAR FACTORS AFFECT SPRINT PERFORMANCE AND PRESENT STRENGTH AND CONDITIONING COACHES WITH SIGNIFICANT CHALLENGES. THIS ARTICLE THEREFORE AIMS TO JUSTIFY THE INCLUSION OF A CONCURRENT RESISTANCE TRAINING AND FLYING 200-M TIME TRAIL PROGRAM AS AN INTERVENTION TO INCREASE THE FLYING 200-M PERFORMANCE OF A MASTERS TRACK CYCLIST (SEE, VIDEO, SUPPLEMENTAL DIGITAL CONTENT 1, http://links.lww.com/scj/a182).
... Most of the muscular activities become less efficient and less responsive with ageing as a result of a decrease in the nervous activity and nerve conduction. (11) Also with ageing, the total water content of the tissue decreases and loss of hydration also adds to the inelasticity and stiffness. (12) Iyengar yoga, one of the active, or Hatha, yoga techniques, is a system for developing physical and mental well-being through stretching of all muscle groups for strength, flexibility, and physical balance. ...
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Background : The geriatric population is defined as population aged 60 years and above. (1)During this age many of the systems undergo deterioration. Balance problems in elderly are most commonly due to multi factorial condition which may include age related or disease-related declines in the balance system. Research shows that altered balance is the greatest collaborator towards falls in the elderly with a high correlation between balance deficit and the incidence of falls. Iyengar yoga, one of the active, or Hatha, yoga techniques, is a system for developing physical and mental well-being through stretching of all muscle groups for strength, flexibility, and physical balance. Yoga as a complementary therapy is thought to be more therapeutic than traditional exercise because it involves active engagement between mind and body. Its practice has been associated with increased muscle strength, endurance, flexibility, range of motion and cardiopulmonary endurance. It mainly works on increasing body awareness and proprioception, which will lead to improvement of balance in older adults. Objectives: To compare pre and post score of Modified Clinical Test of Sensory Interaction in Balance (CTSIB-M). To compare pre and post score of Time up and go test. Materials and Methodology: This was an experimental study that included 40 participants, healthy older adults between the age group 60-75 years, both male and female. The subjects were randomly divided in to 2 groups; Group A was the experimental group whereas group B was the control group. The experimental group was made to perform yogasanas for the duration of four weeks for 5 times a week whereas the control group was not given any intervention. Result and Conclusion: The study conducted concludes that yogasanas are effective in improving balance in elderly individuals at the end of four weeks compared to control group. Thus, it can be used clinically to improve balance in geriatric population.
... While a reduced number of weekly sets may be insufficient to promote more significant hypertrophy, excessive sets may produce prolonged muscle damage and consequently, decrease adaptive response in older people chronically (Hamada et al., 2005;Ferri et al., 2006;Fell and Williams, 2008;Sorensen et al., 2018). Yet, the dose-response of volume on muscle damage in older individuals has to be determined. ...
... Many of these athletes want to improve their performance but the ageing process is associated with declines in athletic capability associated with reduced muscle mass (sarcopenia), strength and power (dynapenia; Brunner et al., 2007;Clark & Manini, 2008;Fell & Williams, 2008;Narici, Reeves, Morse & Maganaris, 2004;Welle, 2002). ...
Thesis
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Little is known about the muscle function capabilities of trained middle-aged males and how they differ to younger counterparts. Accordingly, the overall aim of the research documented in this thesis was to compare the acute muscle function responses to resistance exercise in middle-aged and young resistance trained males. The first study (Chapter 3) examined the intra- and inter-day reliability of an ecologically valid device (FitroDyne rotary encoder) for measuring upper and lower-body muscle function during three popular multi-jointed resistance training exercises (bench press, squat, and bent-over-row), and confirmed that it was capable of detecting moderate changes in muscle function across a range of submaximal loads. In the second study (Chapter 4) the load-velocity and load-power relationships were investigated during the same exercises among 20 young (age 21.0 ± 1.6 y) and 20 middle-aged (age 42.6 ± 6.7 y) resistance trained males, and it emerged that, despite their regular training, the middle-aged males were unable to achieve velocities at low external loads and peak powers at all external loads as high as the young males across a range of external resistances. Study three (Chapter 5) proceeded to compare the internal (heart rate (HR), OMNI-ratings of perceived exertion (RPE) and sRPE) and external (peak velocity and power and volume load) loads experienced during high volume squatting exercise, and the fatigue responses among nine young (age 22.3 ± 1.7 years) and nine middle-aged (age 39.9 ± 6.2 years) resistance trained males. The findings highlighted that internal, but not certain markers of external (peak power and volume load), load responses can be monitored during exercise in a like manner between these age groups. Moreover, compared to young resistance trained males, middle-aged males can expect greater decrements in peak power after lower-limb resistance exercise. In the final study (Chapter 6), the time-course of recovery in nine trained young (age 22.3 ± 1.7 years) and nine trained (39.9 ± 6.2 years) and nine untrained (44.4 ± 6.3 years) middle-aged males after high volume lower-body resistance (muscle damaging) exercise was investigated. Of practical importance, it emerged that compared to the young males, the trained middle-aged males experienced greater symptoms of muscle damage and an impaired recovery profile, the implication of which is the need for trained middle-aged males to adopt strategies to enhance their recovery. Furthermore, both middle-aged groups experienced similar symptoms of muscle-damage, albeit the untrained group demonstrated greater losses in peak power at low and high external loads. For the first time, the current research has determined that middle-aged males, despite regular resistance training, are subject to losses in peak velocity and power output across a range external loads, compared to young males. When undergoing lower-body resistance training to ameliorate these decrements, applied practitioners can use internal load markers and peak velocity, but not peak power or volume load, to monitor trained young and middle-aged males alike. Furthermore, the muscle damage response (24 to 72 h), and losses in peak power (0 to 72 h), after lower-body resistance exercise are greater in trained middle-aged than young males. Consequently, future research should seek to corroborate these observations in upper-body exercise and determine the effectiveness of strategies (e.g. nutritional intake) to enhance recovery in middle-aged males.
... showed that the magnitude of the declines in cycling and running performances with advancing age (until 70 years of age) at Olympic Triathlon (∼ 3 h) was less pronounced than at Ironman triathlon (∼ 15 h). Greater muscular fatigue following dynamic contractions (Christie, Snook, & Kent-Braun, 2011;Krüger, Aboodarda, Samozino, Rice, & Millet, 2018), lower resistance to muscle damage and slower recovery (Close, Kayani, Vasilaki, & McArdle, 2005;Fell & Williams, 2008;Lavender & Nosaka, 2006), and alterations in substrate oxidation with advancing age (Mittendorfer & Klein, 2001) could explain in part the greater age-related decline in Ironman performances compared to shorter endurance performances even if these assumptions need to be verified in the context of ultra-endurance events. Interestingly, the age-related decline in HI performances appeared less pronounced for 180-km cycling compared to 3.8 km swimming and 42-km running. ...
Article
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This study aimed to analyse the performance of Hiromu Inada (HI), an 85-year-old triathlete, who became the oldest athlete in the world to complete the famous Hawaii Ironman triathlon consisting of a 3.8 km swim, 180-km cycle and 42-km run. HI swam in 1 h 51 min, cycled in 8 h 02 min, ran in 6 h 28 min and took 31 min for his transitions, for a total time of 16 h 53 min. Compared to the winner's speed, HI was 55, 47 and 58% slower in swimming, cycling and running, respectively. For the same age-group category (i.e. 85-89 years), the age-related decline in performances of HI are more pronounced compared to the age-related decline in performance of shorter duration endurance single discipline such as 1500-m swimming, 1-h track cycling or marathon running. To our knowledge, the performance of HI represents the first written observation of a master athlete older than 85 years old who officially finished an ultra-endurance event. The HI case is a clear example that humans can retain remarkable functionality until the end of their life span… if they train for it.
... Increasing age in men commonly leads to a body composition remodeling, decreasing both bone and muscle mass [19], and consequently leading to reductions in both aerobic capacity, anaerobic muscle power, and strength [5,17,19,28]. Although regular training delays these age-related effects on physical performance, most of master athletes reduce their training load to some extent as they age [29], perhaps mainly for muscle recovery and consequently to prevent injuries [30][31][32]. These factors may lead to physiological and architectural muscle adaptations that result in speed performance decrease, such as lower maximum strength of lower limbs muscles [33], lower rate of force development and transmissions [34], and reduction in elastic energy storage and recovery in tendons [35]. ...
Article
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Purpose To investigate the slope of age-related performance decrease of male master athletes competing the 100 m, 400 m, and 10,000 m running events. Methods Sample was composed by official data from World Masters Rankings for years 2013–2016. Age and performance data were collected from 2937 athletes between 30 and 105 years. Performance was plotted against age and calculated a trendline for polynomial regression for each event using three different data dispositions: Top-20—best 20 athletes of each age group, all years of analysis; Top-3—best three athletes of each age group, all years of analysis; and annual Top-3—best three athletes of each age group, each year analyzed separately. The age-related point of substantial performance decline was determined by two mathematical methods, Dmax, and log–log. Results The annual-Top-3 (age group Top-3 athletes in each year) disposition indicated an early performance decline in 10,000 m in comparison with the 100 and 400 m for both methods (p < 0.05). Top-3 (Top-3 athletes of each age group) analysis also indicated an earlier performance decline in 10,000 m (Dmax: 61.2 years/log–log: 67.6 years), followed by 400 m (72.9 years/77.5 years) and 100 m (76.7 years/78.2 years). Conclusion In conclusion, the critical age after which the aging-related decline in masters athletes’ performance is accelerated, and occurs earlier in endurance runners than sprinters.
... The muscle soreness component presented a similar trait, as V1 and V2 runners were exhibiting a higher level of muscle pain after the race. This findings also corroborate recent works suggesting that athletes age should be taken into account for recovery kinetics [4]: aging may produce an increased depletion of energy substrates, greater muscle damage and an altered feeling of fatigue after a race [8,9,25]. The rate of muscle protein synthesis, measured 72 h after a MUM, is lower in older Hooper ndex Days RACE -UTMB athletes, suggesting less efficient "repair and remodelling" mechanisms in these athletes [6]. ...
Article
Purpose The interaction between sleep and recovery is a fundamental issue for ultra-marathoners, especially after an ultra-trail, but literatures on this matter remains are scarce. The main objectives were (1) to describe sleep parameters during the nights following an ultra-endurance event in amateur trail runners, (2) to evaluate the recovery kinetics, and (3) to assess the relationship between sleep parameters and recovery. Methods Nineteen race finishers were tested daily, from 10 days before to 10 days after the Ultra-Trail du Mont-Blanc® (UTMB®). Hooper Index (HI) was used to assess recovery and sleep parameters (total sleep time, TST and wake after sleep onset, WASO) were monitored using a wrist-worn actigraph. Results HI was higher than baseline until day 5 after the race (P < 0.05) and younger athletes had a lower HI than older ones during the recovery period (P < 0.001). TST was not modified by the race, but there was a WASO peak on the second night after. Positive correlations were found between WASO and muscle soreness (P < 0.001) and between TST and HI (P < 0.05). Conclusions In conclusion, participants needed 6 days for recovery after UTMB® and younger runners seemed to recover faster than older ones. Post-race sleep quantity did not increase, but the second night was more fragmented, most likely due to muscle soreness. Correlations between sleep and recovery parameters highlighted the key role of sleep for recovery.
... Diese theoretischen Überlegungen sind jedoch bislang unzureichend durch Studien abgesichert, bei denen die altersbedingt unterschiedliche körperli-che Leistungsfähigkeit als eine konfundierende Variable angemessen berücksichtigt wurde. . 8.3: Theoretisches Modell zu unterschiedlichen Zeitverläufen der Ermüdungs-Regenerations-Kinetik älterer Sportler (farbige Linien) im Vergleich zu jüngeren Sportlern (schwarze Linie) nach einer intensiven Trainingsbelastung (modifiziert nachFell & Williams, 2008). eine Verlängerung der Erholungszeit im Alter werden verschiedene physiologische Mechanismen angeführt, die zum Teil auch mit entsprechenden Befunden belegt sind. ...
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Einleitung. Das Interesse des Leistungssports am „Regenerationsmanagement“ (Kurzname des Projekts: REGman) ist ungebrochen, wie u. a. die Vielzahl internationaler Publikationen belegen. Ganz offenbar werden auf diesem Gebiet nach wie vor relevante Reserven im Hinblick auf die Leistungsoptimierung gesehen. Der erste 4-Jahres-Abschnitt von REGman I (2013-2016) umfasste im Wesentlichen die Entwicklung eines Diagnostikinventars aus psychometrischen, physiologischen, neuromuskulären und sportmotorischen (Surrogat-) Parametern für unterschiedliche Sportarten sowie die Evaluation der populärsten Regenerationsverfahren, festgelegt anhand von Präferenzen der Spitzenverbände. Bereits im Zuge der Bearbeitung dieser Fragen wurde deutlich, dass ein wesentliches Problem für generalisierende Aussagen die Vielzahl an untersuchungsmethodischen Freiheitsgraden und Fragestellungen ist, die sich durch Sportartspezifika und die Individualität der Athleten ergeben. Insbesondere die folgenden drei Problemfelder konnten in REGman I herausgearbeitet werden und repräsentieren die Kernthemen des zweiten Abschnitts 2017-2020 von REGman II: 1. Individualität des Spitzensportlers 2. Auswahl, Applikation und Zeitpunkte von Regenerationsinterventionen 3. Sportart- und altersspezifische Besonderheiten
... Usta sporcular olarak belirtilen yaşlı sporcular ise hem kemik ve kas kaybı hem de düşen metabolizma ve hidrasyon seviyeleri nedeniyle daha özel bakım ve beslenme düzenlerine ihtiyaç duyarlar. Kilo alımını engellemek, performans kaybı riskini azaltmak ve kemik yoğunluğunu korumak için fiziksel aktiviteyle birlikte beslenme kalitesi yaşlı sporcunun hem performansını hem genel sağlığını korumaktadır (Fell & Williams, 2008). ...
Article
ZET Sporcu beslenmesi temel olarak sporcunun performansını ve genel sağlığını korumak amacıyla oluşturulan özel bir beslenme şeklidir. Her sporcunun vücut kitle indeksi, yaşı, cinsiyeti, engel durumu ve birçok sebebe göre beslenme düzeni özelleştirilmektedir. Yaş faktörü sporcunun besin alımı ve gerekli makro ve mikro besin ihtiyacının hesaplanmasında önemli kıstaslardan biridir. Çocuk ve ergen sporcular büyüme ve gelişme dönemi göz önüne alınarak beslenme düzenine yönlendirilirler. Yetişkin ve yaşlı sporcuların ise enerji ihtiyaçları benzerlik gösterse de yaşlı sporcularda anaerobik ve aerobik kapasitenin düştüğü göz önüne alınmalıdır. Kadın sporcularda ise özellikle estetik unsurun önemli olduğu bir spor dalıysa yetersiz beslenme prevelansı çok yaygındır. Bunun önüne geçmek için iyi bir beslenme eğitimi ve profesyonel beslenme uzmanlarının desteği gerekmektedir. Paralimpik ve ampüte sporcularda ise eğer uzuv kaybı varsa vücut kitle indeksinin hesaplanmasının zorluğu göz önüne alınarak beslenme düzeni hazırlanmalıdır. Bu derlemede özel endişeleri bulunan sporculara ve bu sporcuların beslenme düzenine odaklanılmıştır. Bu doğrultuda alanyazın taraması yapılmış ve incelenen kaynaklar tartışılmıştır. ABSTRACT Sports nutrition is basically a special form of nutrition created to protect the performance and general health of the athlete. The diet of each athlete is customized according to their body mass index, age, gender, disability and many reasons. The age factor is one of the important criteria in calculating the nutritional intake and the necessary macro and micronutrient needs of the athlete. Children and adolescent athletes are directed to the diet, taking into account the growth and development period. Although the energy needs of adult and elderly athletes are similar, it should be taken into consideration that anaorebic and aerobic capacity decreases in elderly athletes. In female athletes, the prevalence of malnutrition is very common, especially if it is a sport where aesthetics are important. To prevent this, a good nutrition education and the support of professional nutrition experts are required. In paralympic and amputated athletes, if there is a loss of limbs, a diet should be prepared by considering the difficulty of calculating body mass index. This review focuses on athletes with special concerns and their diet. In this direction, the literature was scanned and the analyzed sources were discussed.
... In older women, an RT volume reduction is often necessary due to changes in daily life activities or routines, such as caring for grandchildren, husband, or parents; engaging in community activities; performing housework. It is essential to highlight that manipulation of RT volume over time may be particularly crucial for older individuals, given that aging seems to slow the recovery process from exercise [20]. However, it is unknown whether the acquired adaptations from previous training such as muscular strength gains and muscle hypertrophy are maintained, decreased, or perhaps even increased when the altered variable is solely the number of sets per exercise within an RT session. ...
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We compared the effects of different resistance training (RT) volume reduction strategies on muscular strength and lean soft-tissue (LST) in older women. Fifty seven physically independent women (> 60 years) performed a 20-week pre-conditioning phase of a standardized whole-body RT program (eight exercises, three sets, 8-12 repetitions, three sessions a week), and were then randomly assigned to one of the following conditions: reduced volume for a single-set (RV1, n = 20) or two sets (RV2, n = 19), or maintained volume of three sets (MV, n = 18) for eight weeks (specific-training phase). Muscular strength in the chest press, leg extension, and preacher curl exercises was determined by one-repetition maximum tests. A dual-energy X-ray absorptiometry device was used to estimate LST. An increase in muscular strength (16.3–32.1%) and LST (3.2–7.9%) was observed after the pre-conditioning phase. There was an increase in chest press for all groups (9.4–16.7%) after the specific-training phase. In contrast, only MV increased significantly in the leg extension (4.4%). No between-group differences were revealed for LST in the specific-training phase. Our results suggest that re-duced-RT volume from three to one set per exercise for eight weeks seems sufficient to retain neuro-muscular adaptations in older women.
... Usta sporcular olarak belirtilen yaşlı sporcular ise hem kemik ve kas kaybı hem de düşen metabolizma ve hidrasyon seviyeleri nedeniyle daha özel bakım ve beslenme düzenlerine ihtiyaç duyarlar. Kilo alımını engellemek, performans kaybı riskini azaltmak ve kemik yoğunluğunu korumak için fiziksel aktiviteyle birlikte beslenme kalitesi yaşlı sporcunun hem performansını hem genel sağlığını korumaktadır (Fell & Williams, 2008). ...
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ZET Sporcu beslenmesi temel olarak sporcunun performansını ve genel sağlığını korumak amacıyla oluşturulan özel bir beslenme şeklidir. Her sporcunun vücut kitle indeksi, yaşı, cinsiyeti, engel durumu ve birçok sebebe göre beslenme düzeni özelleştirilmektedir. Yaş faktörü sporcunun besin alımı ve gerekli makro ve mikro besin ihtiyacının hesaplanmasında önemli kıstaslardan biridir. Çocuk ve ergen sporcular büyüme ve gelişme dönemi göz önüne alınarak beslenme düzenine yönlendirilirler. Yetişkin ve yaşlı sporcuların ise enerji ihtiyaçları benzerlik gösterse de yaşlı sporcularda anaerobik ve aerobik kapasitenin düştüğü göz önüne alınmalıdır. Kadın sporcularda ise özellikle estetik unsurun önemli olduğu bir spor dalıysa yetersiz beslenme prevelansı çok yaygındır. Bunun önüne geçmek için iyi bir beslenme eğitimi ve profesyonel beslenme uzmanlarının desteği gerekmektedir. Paralimpik ve ampüte sporcularda ise eğer uzuv kaybı varsa vücut kitle indeksinin hesaplanmasının zorluğu göz önüne alınarak beslenme düzeni hazırlanmalıdır. Bu derlemede özel endişeleri bulunan sporculara ve bu sporcuların beslenme düzenine odaklanılmıştır. Bu doğrultuda alanyazın taraması yapılmış ve incelenen kaynaklar tartışılmıştır. ABSTRACT Sports nutrition is basically a special form of nutrition created to protect the performance and general health of the athlete. The diet of each athlete is customized according to their body mass index, age, gender, disability and many reasons. The age factor is one of the important criteria in calculating the nutritional intake and the necessary macro and micronutrient needs of the athlete. Children and adolescent athletes are directed to the diet, taking into account the growth and development period. Although the energy needs of adult and elderly athletes are similar, it should be taken into consideration that anaorebic and aerobic capacity decreases in elderly athletes. In female athletes, the prevalence of malnutrition is very common, especially if it is a sport where aesthetics are important. To prevent this, a good nutrition education and the support of professional nutrition experts are required. In paralympic and amputated athletes, if there is a loss of limbs, a diet should be prepared by considering the difficulty of calculating body mass index. This review focuses on athletes with special concerns and their diet. In this direction, the literature was scanned and the analyzed sources were discussed.
... Age should also be considered when prescribing set end points. Evidence indicates that recovery capacity tends to decline with advancing age, necessitating a longer recuperative period after a RT bout (182). Given that failure training negatively impacts recovery (183), its implementation in training programs conceivably could have a greater detrimental effect on older athletes. ...
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... Research has presented evidence of differences in acute recovery of physiological parameters after fatiguing exercise between younger and older participants. For similar exercise stimuli, elderly people require a longer recovery period when returning to baseline levels after exercise [29]. Although this study did not reveal a significant difference in exercise recovery between the elderly participants with and without exercise habits, the EEG results demonstrate that the elderly participants who exercised regularly had superior brain regulation of exercise load than did those who exercised occasionally. ...
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Athletes experience minor fatigue and acute reductions in performance as a consequence of the normal training process. When the balance between training stress and recovery is disproportionate, it is thought that overreaching and possibly overtraining may develop. However, the majority of research that has been conducted in this area has investigated overreached and not overtrained athletes. Overreaching occurs as a result of intensified training and is often considered a normal outcome for elite athletes due to the relatively short time needed for recovery (approximately 2 weeks) and the possibility of a supercompensatory effect. As the time needed to recover from the overtraining syndrome is considered to be much longer (months to years), it may not be appropriate to compare the two states. It is presently not possible to discern acute fatigue and decreased performance experienced from isolated training sessions, from the states of overreaching and overtraining. This is partially the result of a lack of diagnostic tools, variability of results of research studies, a lack of well controlled studies and individual responses to training. The general lack of research in the area in combination with very few well controlled investigations means that it is very difficult to gain insight into the incidence, markers and possible causes of overtraining. There is currently no evidence aside from anecdotal information to suggest that overreaching precedes overtraining and that symptoms of overtraining are more severe than overreaching. It is indeed possible that the two states show different defining characteristics and the overtraining continuum may be an oversimplification. Critical analysis of relevant research suggests that overreaching and overtraining investigations should be interpreted with caution before recommendations for markers of overreaching and overtraining can be proposed. Systematically controlled and monitored studies are needed to determine if overtraining is distinguishable from overreaching, what the best indicators of these states are and the underlying mechanisms that cause fatigue and performance decrements. The available scientific and anecdotal evidence supports the existence of the overtraining syndrome; however, more research is required to state with certainty that the syndrome exists.
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This study examined exercise-induced muscle damage, repair, and adaptation in 10 college age women and 10 women over age 60. On two sessions spaced 7 days apart, subjects performed an eccentric exercise of the forearm flexors consisting of 24 muscle actions at an intensity of 115% of isometric strength. Serum creatine kinase activity, flexed and relaxed elbow joint angles, and muscle pain were assessed prior to and for 5 days after each exercise session. The exercise resulted in similar changes in CK, muscle pain, and inability to fully flex the forearm for old and young subjects. The old group demonstrated greater muscle shortening (a decrease in the relaxed elbow joint angle). The old and young groups adapted to the first exercise such that changes in all criterion measures were reduced following the second exercise. For the physically active subjects in this study, the damage process (with the exception of muscle shortening) takes a similar course for old and young. The repair process is equally as effective in old and young, and older subjects show the same ability to adapt to the damage as young subjects.
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Chapter
Physiological reactions to, and mechanisms associated with exercise-induced muscle damage and subsequent repair processes have been well characterized in young adults. This chapter examines evidence from human- as well as animal-based studies linking aging with an increased susceptibility to exercise-induced muscle damage and an impairment of muscle repair and adaptation processes. Further, the possible physiological mechanisms associated with such age-related changes are discussed.
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AGE affects man's ability to run fast but to date there has been little interest in quantitating the relationship. The few published studies, such as the one by Dill on marathon runner Clarence DeMar1, are concerned mainly with reporting lung volume, heart rate, and other physiological characteristics of notable performers, with only brief reviews of race performances over the runner's life span.
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Plasma creatine kinase (CK) activity has often been used as a marker of exercise-induced skeletal muscle damage. While the pattern of muscle damage following eccentric exercise has been established in young adults, there is little data available on eccentric exercise-induced muscle damage in older individuals. The purpose of this study was to compare ultrastructural changes in skeletal muscle following high intensity eccentric exercise of young and older men and to determine whether CK activity is a reliable predictor of muscle damage. Five young (20-30 yr) and five older untrained men (59-63 yr) performed three 15-min bouts of eccentric exercise at 90, 80, and 70% of maximal concentric power output. There was a prolonged increase in CK up to 10 d following exercise that was not significantly different between groups. Light and electron microscopic examination of needle biopsies obtained from the vastus lateralis showed evidence of focal damage in greater than 90% of the post-exercise fibers examined in the older subjects, compared with values ranging from 5 to 50% reported previously in young subjects. Quantitative analysis using light microscopy showed greater damage in the older subjects than reported previously in young subjects. These data suggest that older adults experience greater muscle damage following eccentric exercise than young subjects, which may be due in part to the smaller muscle mass and lower VO2max seen in older men. In addition, there was no relationship between CK activity and the corresponding amount of muscle damage observed in each subject, suggesting that CK activity may be a poor predictor of exercise-induced muscle damage.
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We tested the hypothesis that after the same amount of contraction-induced injury, skeletal muscles in old mice regenerate less well than muscles in young mice. Extensor digitorum longus (EDL) muscles in young and old mice were exposed to 15 min of lengthening contractions. The amount of injury was evaluated at 3, 7, 14, 28, and 60 days by measurements of maximum isometric tetanic force (Po) and number of fibers per cross section. When values 3 days after lengthening contractions were expressed as a percentage of control values, the Po (approximately 34%) and fiber number (approximately 80%) for muscles in old mice were not different from those in young mice, suggesting that muscles in old and young mice were injured to the same degree. By 28 days, injured muscles in young mice regained control values for Po and fiber number. In contrast, at 28 days, injured muscles in old mice recovered approximately 84 and approximately 87% of control values for Po and fiber number, respectively, and deficits in Po persisted at 60 days. We conclude that injured muscles regenerate less well in old mice than in young mice.
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We tested the hypotheses that 1) muscles of old mice are more susceptible to injury than muscles of young and adult mice, and 2) secondary or delayed onset injury results from free radical damage. Extensor digitorum longus muscles were injured in situ by lengthening contractions. Injury was assessed by measurement of maximum isometric tetanic force (Po) expressed as a percentage of the control value and by morphological damage. Mice were treated with a free radical scavenger, polyethylene glycol-superoxide dismutase (PEG-SOD). Three days postinjury, the Po of 44% for muscles of nontreated old mice was significantly lower than the Po of 58 and 61% for those of young and adult mice. In each group, the secondary injury at 3 days was alleviated by treatment with PEG-SOD. For treated muscles of young, adult, and old mice, values for Po were 88, 80, and 70%, respectively. We conclude that muscles of old mice are more susceptible to injury than muscles of young or adult mice and that free radicals contribute to the secondary or delayed onset injury.
The purpose of the present study was to determine if old individuals show a greater exercise-induced decrement in motor performance and slower recovery compared to young individuals. Ten college-age women (23.6 years) and ten older women (67.4 years) performed an exercise consisting of 24 eccentric actions of the forearm flexors. In young subjects, eccentric exercise is known to produce repairable muscle damage. Before the exercise and for 5 days after, isometric strength, soreness, reaction time, and movement time were measured. For both groups, strength was reduced and soreness developed in the days following the exercise, generally indicating that muscle damage had occurred. The older subjects showed a slower strength recovery such that by 5 days after exercise they had not returned to their initial level of strength. There was no significant difference in soreness development between groups. Reaction time and movement time were not adversely affected by the exercise. Thus, the older subjects demonstrated a slower strength recovery after damage-inducing exercise, and, with regard to response speed, the older subjects could compensate for the impaired muscle function as well as the younger subjects.
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Eight men performed 10 sets of 10 eccentric contractions of the knee extensor muscles with one leg [eccentrically exercised leg (EL)]. The weight used for this exercise was 120% of the maximal extension strength. After 30 min of rest the subjects performed two-legged cycling [concentrically exercised leg (CL)] at 74% of maximal O2 uptake for 1 h. In the 3 days after this exercise four subjects consumed diets containing 4.25 g CHO/kg body wt, and the remainder were fed 8.5 g CHO/kg. All subjects experienced severe muscle soreness and edema in the quadriceps muscles of the eccentrically exercised leg. Mean (+/- SE) resting serum creatine kinase increased from a preexercise level of 57 +/- 3 to 6,988 +/- 1,913 U/l on the 3rd day of recovery. The glycogen content (mmol/kg dry wt) in the vastus lateralis of CL muscles averaged 90, 395, and 592 mmol/kg dry wt at 0, 24, and 72 h of recovery. The EL muscle, on the other hand, averaged 168, 329, and 435 mmol/kg dry wt at these same intervals. Subjects receiving 8.5 g CHO/kg stored significantly more glycogen than those who were fed 4.3 g CHO/kg. In both groups, however, significantly less glycogen was stored in the EL than in the CL.
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Exercise can damage the muscle membrane, followed by leakage of certain muscle proteins into the bloodstream. This postexercise response differs for males and females; as an explanation for this difference it has been suggested that oestrogens have a protective effect on the female muscle membrane. We recently developed an animal exercise model in which postexercise damage can be studied in laboratory animals in vivo. A postexercise dimorphism, similar to that in humans, exists in rats and indirect evidence for the involvement of oestradiol (E2) was found. We report here 1) that ovariectomized females show postexercise damage like males, 2) that this response can be prevented by E2-replacement before exercise, and 3) that males, after E2-treatment, no longer show postexercise muscle damage. We therefore conclude that oestradiol indeed plays an important role in protecting skeletal muscle, both in females and in males.
The 24 h recovery pattern of contractile properties of the triceps surae muscle, following a period of muscle fatigue, was compared in physically active young (25 years,n = 10) and elderly (66 years,n = 7) men. The fatigue test protocol consisted of 10 min of intermittent submaximal 20 Hz tetani. The maximal twitch (p t) and tetanic force at 3 frequencies (10, 20 and 50 Hz) were determined at baseline and at 15 min, 1, 4 and 24 h after fatiguing the muscle. Maximal voluntary contraction (MVC) and vertical jump (MVJ) were also assessed. The loss of force during the fatigue test was not significantly different between the young (18±13%) and elderly (22±15%). Both groups showed similar and significant reductions of Pt (15%), tetanic force (10 to 35%) and rate of force development (dp/dt) (20%) 15 min and 1 h into recovery. The loss of force was greater at the lower stimulation frequencies of 10 and 20 Hz. Time-to-peak tension was unchanged from baseline during recovery in either group. The average rate of relaxation of twitch force (−dPt/dt) was decreased (p<0.05) and half-relaxation time significantly increased at 15 min and 1 h in the elderly but not the young. The findings indicate that after fatiguing contractions, elderly muscle demonstrates a slower return to resting levels of the rate and time course of twitch relaxation compared to the young.
Recovery of the rate of dynamic muscular endurance was measured in two groups of college-aged males. Subjects were required to perform elbow flexion (between the angles of 70 and 170 degrees) for as long as possible at the rate of 38 contractions/min while loaded with 1/6 of their maximum isometric strength (MVC). The task was terminated when the subject fell four contractions behind the required cadence or failed to complete two successive contractions. Subsequent to the task the subject was given a predetermined rest period after which a second fatigue bout to failure was performed. The rest intervals for Gp I (n = 22) were 5, 15, 45, 135, 405, and 1215 seconds, while the rest intervals for Gp II (n = 17) were 10, 30, 90, 270, 810, and 2550 s. Each subject completed six recovery intervals with the order of administration assigned at random. The percentage of recovery was calculated by dividing the exercise time of the first bout into the time of the second bout. These normalized data for the two groups were combined for analysis providing a 12 point recovery curve. The percentage of recovery ranged from 15.4% after 5 s to 91.8% after 2550 s. Analysis of the data revealed that the recovery pattern of dynamic muscular endurance progressed very rapidly initially, reached 50% at approximately 2 min and 15 s and was slightly less than 90% complete at 20 min. Exponential analysis of these data yielded a three-component curve.
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Alterations in the intensity and pattern of spontaneous running activity as rats increase in age from 7 wk to 1 yr was studied in male rats placed in exercise wheel cages. Daily running records were obtained on 27 rats for periods up to 12 mo, and 24-h activity recordings were made of selected runners to study the variation in activity during the day. The data indicate that for rats running over 2,940 revolutions (or 2 miles/day), the maximum intensity of running attained can be divided into a group of high achievers (approximately 8 miles/day) and moderate achievers (averaging 4.5 miles/day). For both groups, spontaneous running activity reached maximal rates after 4-5 wk. This maximal rate was sustained for 7-8 wk, then fell to levels approximately 60% of maximum for 4-5 mo, and then fell again to levels approximately 25% of maximum from 8 to 12 mo of age. The hourly pattern of running activity during the day was defined in rats of increasing age, who averaged 13,280, 6,662, 3,874, and 1,755 rev/day, corresponding to 9.0, 4.5, 2.6, and 1.2 miles/day, respectively. The overall patterns at each level indicated that the major running period occurred between 6:00 P.M. and 6:00 A.M., the greater activity of younger rats was paralleled by faster speeds and longer duration at each hour of the day, and the peak running activity for each group generally occurred between 7:00 and 9:00 P.M. In summary, there is a progressive loss in speed and duration of spontaneous running activity as male rats increase in age, with intensity of exercise falling below 2 miles/day after 7-8 mo of age.
Article
Perceived muscle soreness ratings, serum creatine kinase (CK) activity, and myoglobin levels were assessed in three groups of subjects following two 30-min exercise bouts of downhill running (-10 degrees slope). The two bouts were separated by 3, 6, and 9 wk for groups 1, 2, and 3, respectively. Criterion measures were obtained pre- and 6, 18, and 42 h postexercise. On bout 1 the three groups reported maximal soreness at 42 h postexercise. Also, relative increases in CK for groups 1, 2, and 3 were 340, 272, and 286%, respectively. Corresponding values for myoglobin were 432, 749, and 407%. When the same exercise was repeated, significantly less soreness was reported and smaller increases in CK and myoglobin were found for groups 1 and 2. For example, the percent CK increases on bout 2 for groups 1 and 2 were 63 and 62, respectively. Group 3 demonstrated no significant difference in soreness ratings, CK activities, or myoglobin levels between bouts 1 and 2. It was concluded that performance of a single exercise bout had a prophylactic effect on the generation of muscle soreness and serum protein responses that lasts up to 6 wk.