Long-term aerobic exercise is associated with greater muscle strength throughout the life span

Exercise prescription prescriptions for frailty improvement in older adults: An evidence-based approach based on the 2024 older adult compendium

OBJECTIVE

This study explored the dose-response relationship of exercise prescriptions for improving frailty in older adults, based on the 2024 Older Adult Compendium. It aims to provide evidence-based support for developing frailty intervention programs and their clinical application.

METHODS

A comprehensive search was conducted in PubMed, OVID, Cochrane Library, Web of Science, and Scopus from inception to November 5th, 2024. Randomized controlled trials (RCTs) related to exercise interventions in older adults were included. Relevant studies meeting the inclusion criteria were selected, and data were extracted for further analysis. The quality of the included studies was assessed. Meta-analysis was performed using R, and the standardized mean difference (SMD) with 95 % confidence intervals (95 % CI) was used to quantify effect sizes.

RESULTS

A total of 16 eligible RCTs comprising 2,716 older adults were included. The meta-analysis revealed that exercise significantly improved frailty among older adults [SMD = -0.81, 95 % CI (-1.25, -0.38), P < 0.001]. However, high-intensity exercise did not demonstrate a significant effect on frailty improvement [SMD = -0.45, 95 % CI (-0.96, 0.06), P = 0.3]. The analysis indicated a nonlinear dose-response relationship between exercise and frailty improvement. The predicted values for frailty improvement at the minimum and maximum exercise doses recommended by the World Health Organization (600 MET-minutes/week and 1200 MET-minutes/week, respectively) were -0.79 (95 % CI [-1.17, -0.41]) and -1.39 (95 % CI [-2.62, -0.15]), respectively.

CONCLUSION

Low- to moderate-intensity exercise significantly improves frailty among older adults, while high-intensity exercise programs are not recommended.

Fat-Free Mass: Friend or Foe to Metabolic Health?

BACKGROUND

Fat mass (FM) and fat-free mass (FFM) are body composition estimates commonly reported in research studies and clinical settings. Recently, fat-free mass indexed to height (fat-free mass index; FFMI) has been shown to be positively associated with impaired insulin sensitivity or insulin resistance. Consequently, hypertrophic resistance training which can increase FFM was also questioned. This paper sets out to evaluate these propositions.

METHODS

In this narrative review, we discuss possible reasons that link FFMI to adverse metabolic health outcomes including the limitations of the body composition model that utilizes FFM. The safety of resistance training is also briefly discussed.

RESULTS

Approximately 50% of FFM is comprised of skeletal muscle (SM), with the other 50% being viscera, skin, and bone; FFM and SM cannot be conflated. FFM and fat mass (FM) can both rise with increasing body weight and adiposity, indicating a positive correlation between the two compartments. Risk assessment models not adequately adjusting for this correlation may cause erroneous conclusions, however which way FM and FFM are indexed. Adipose tissue accumulation with weight gain, measured by dual-energy X-ray absorptiometry or bioelectrical impedance, can inflate FFM estimates owing to increased connective tissue. Increased adiposity can also result in fat deposition within skeletal muscle disrupting metabolic health. Importantly, non-skeletal muscle components of the FFM, i.e., the liver and pancreas, both critical in metabolic health, can also be negatively affected by the same lifestyle factors that impact SM. The most frequently used body composition techniques used to estimate FM and FFM cannot detect muscle, liver or pancreas fat infiltration. Prospective evidence demonstrates that resistance training is a safe and effective exercise modality across all ages, especially in older adults experiencing age- or disease-related declines in muscle health.

CONCLUSIONS

The association between FFM and insulin resistance is largely an artefact driven by inadequate assessment of skeletal muscle. If FM and FFM are used, at the minimum, they need to be evaluated in context with one another. Body composition methods, such as magnetic resonance imaging, which measures skeletal muscle rather than fat-free mass, and adipose tissue as well as muscle ectopic fat, are preferred methods. Resistance training is important in achieving and maintaining good health across the lifespan. While strength and power are critical components of resistance training, the reduction of skeletal mass through ageing or disease may require hypertrophic training to mitigate and slow down the progression of this often-inevitable process.

Effects of aerobic training with blood flow restriction on aerobic capacity, muscle strength, and hypertrophy in young adults: a systematic review and meta-analysis

Aerobic training with blood flow restriction (AT-BFR) has shown promise in enhancing both aerobic capacity and exercise performance. The aim of this review was to systematically analyze the evidence regarding the effectiveness of this novel training method on aerobic capacity, muscle strength, and hypertrophy in young adults. Studies were identified through a search of databases including PubMed, Scopus, Web of Science, SPORTDiscus, CINAHL, Cochrane Library, and EMBASE. A total of 16 studies, involving 270 subjects, were included in the meta-analysis. The results revealed that AT-BFR induced greater improvements in VO2max (SMD = 0.27, 95%CI: [0.02, 0.52], p < 0.05), and muscle strength (SMD = 0.39, 95%CI: [0.09, 0.69], p < 0.05), compared to aerobic training with no blood flow restriction (AT-noBFR). However, no significant effect was observed on muscle mass (SMD = 0.23, 95%CI: [-0.09, 0.56], p = 0.162). Furthermore, no moderating effects on the outcomes were found for individual characteristics or training factors. In conclusion, AT-BFR is more effective than AT-noBFR in improving aerobic capacity and muscle strength, making it a promising alternative to high-intensity training.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42024559872.

Observing the Relationship Between Additional Measures of Handgrip Strength and the 6-Minute Push Test in Ambulatory Young Adults

Manual wheelchair users have been shown to have low functional capacity and limited ability to perform activities of daily living. Conventional protocols for assessing physical attributes such as muscle function in this population have unique boundaries such as expensive testing equipment and procedures not specific to wheelchair propulsion. The measurement of muscle function using electronic handgrip dynamometry has shown promise in assessing additional characteristics beyond strength capacity alone. This study aimed to determine the correlations of electronic handgrip dynamometry derived strength, time to peak force generation, fatigability (22.40±10.12%), isometric control, and asymmetry with aerobic capacity in ambulatory young adults. We included 34 recreationally active ambulatory adults aged 23.76±3.57 years. Muscle function was assessed using electronic handgrip dynamometry. Aerobic capacity was examined using the six-minute wheelchair push test (1112.17±92.84ft). Fatigability (22.40±10.12%) showed a significant, near moderate negative correlation (r=-0.345, p<0.05) with push test outcomes, while the correlation with all other measures was not-significant. Our findings show that electronic handgrip dynamometry derived fatigability is related to aerobic capacity in those who use manual wheelchairs. Given the relationships shown in the current study, electronic handgrip dynamometry has promise for assessing functional health in persons with disabilities, which has particular relevance for SCI, and could be used in clinical practice and physical medicine and rehabilitation (PM&R) as a tool to examine functional capacity in applicable populations. However, future research is warranted to assess the concurrent validity of the additional measures of handgrip strength assessing muscle function.

Factors, mechanisms and improvement methods of muscle strength loss

Muscle strength is a crucial aspect of muscle function, essential for maintaining normal physical activity and quality of life. The global aging population coupled with the increasing prevalence of muscle disorders and strength loss, poses a remarkable public health challenge. Understanding the mechanisms behind muscle strength decline is vital for improving public health outcomes. This review discusses recent research advancements on muscle strength loss from various perspectives, including factors contributing to muscle strength decline, the signaling pathways involved in the deterioration of muscle function, and the methods for assessing muscle strength. The final section explores the influence of exercise stimulation and nutrition on muscle strength.

Effectiveness of cardiac rehabilitation in cancer survivors: A meta-analysis of randomized controlled trials

PURPOSE

This meta-analysis aimed to evaluate available data regarding the potential benefits of cardiac rehabilitation (CR) in cancer survivors.

METHODS

Relevant studies published from inception to April 2024 were retrieved from PubMed, Embase, Web of Science, CENTRAL, CINAHL, PsycINFO, Scopus, CNKI, WanFang, VIP, and CBM databases. Seven randomized controlled trials (RCTs) involving 526 cancer survivors were included in this meta-analysis.

RESULTS

CR increased muscle strength (standardized mean difference (SMD) = 0.39, 95% confidence interval (CI): 0.06 to 0.72, P = 0.020), quality of life (QoL) (SMD = 0.61, 95% CI: 0.40 to 0.82, P < 0.001), and led to a decrease in Body Mass Index (BMI) (mean difference (MD) = -1.11, 95% CI: -2.02 to -0.19, P = 0.020), total cholesterol (TC) (MD = -0.41, 95% CI: -0.69 to -0.14, P = 0.003), triglyceride (TG) (MD = -0.33, 95% CI: -0.63 to -0.03, P = 0.030) and low-density lipoprotein (LDL) (MD = -0.34, 95% CI: -0.57 to -0.12, P = 0.003). The meta-analysis revealed that CR had no statistically significant impact on cardiorespiratory fitness (CRF) and high-density lipoprotein (HDL) levels.

CONCLUSIONS

CR may represent an effective strategy to evaluate cancer survivors because it improves muscle strength and QoL and reduces BMI, TC, TG and LDL levels. Further RCTs with strict study designs and larger sample sizes are required to determine the effects of CR on cancer survivors.

Prevalence and Risk Factors for Hand-Grip-Determined Dynapenia in the Korean Population: A Cross-Sectional Study

Dynapenia refers to muscle weakness related to aging and is defined as a loss of muscle strength associated with muscle quality. The purpose of this study is to identify the prevalence of dynapenia and associated risk factors by gender and age in domestic adults and to provide customized basic data for the prevention of dynapenia through its management. Based on the data from 2014 to 2019 of the Korea National Health and Nutrition Survey, 20,950 adults over the age of 20 who participated in grip strength tests and health surveys were selected as participants. Factors related to dynapenia were analyzed using complex sample multilogistic regression analysis. The prevalence of dynapenia in domestic adults was 6.3%, 4.1% in men, and 8.7% in women. Prevalence in the second decade was 5.3%, in the third decade was 3.2%, in the fourth decade was 3.3%, in the fifth decade was 4.8%, in the sixth decade was 8.9%, and was 24.6% for participants in their seventh decade or beyond. Among the factors related to dynapenia, age, BMI, and alcohol status were common in both men and women; education level, HDL-C, and resistance exercise were common in men; and high blood pressure, high blood sugar, and aerobic exercise were common in women. Our findings indicate that several factors are associated with dynapenia, which should be considered as potential targets for interventions focused on both individual and public health measures.

Review: myogenic and muscle toxicity targets of environmental methylmercury exposure

A number of environmental toxicants are noted for their activity that leads to declined motor function. However, the role of muscle as a proximal toxicity target organ for environmental agents has received considerably less attention than the toxicity targets in the nervous system. Nonetheless, the effects of conventional neurotoxicants on processes of myogenesis and muscle maintenance are beginning to resolve a concerted role of muscle as a susceptible toxicity target. A large body of evidence from epidemiological, animal, and in vitro studies has established that methylmercury (MeHg) is a potent developmental toxicant, with the nervous system being a preferred target. Despite its well-recognized status as a neurotoxicant, there is accumulating evidence that MeHg also targets muscle and neuromuscular development as well as contributes to the etiology of motor defects with prenatal MeHg exposure. Here, we summarize evidence for targets of MeHg in the morphogenesis and maintenance of skeletal muscle that reveal effects on MeHg distribution, myogenesis, myotube formation, myotendinous junction formation, neuromuscular junction formation, and satellite cell-mediated muscle repair. We briefly recapitulate the molecular and cellular mechanisms of skeletal muscle development and highlight the pragmatic role of alternative model organisms, Drosophila and zebrafish, in delineating the molecular underpinnings of muscle development and MeHg-mediated myotoxicity. Finally, we discuss how toxicity targets in muscle development may inform the developmental origins of health and disease theory to explain the etiology of environmentally induced adult motor deficits and accelerated decline in muscle fitness with aging.

In the land of not-unhappiness: On the state-of-the-art of targeting aging and age-related diseases by biomedical research

The concept of the Land of Not-Unhappiness refers to the potential achievement of eliminating the pathologies of the aging process. To inform of how close we are to settling in the land, we summarize and review the achievements of research on anti-aging interventions over the last hundred years with a specific focus on strategies that slow down metabolism, compensate for aging-related losses, and target a broad range of age-related diseases. We critically evaluate the existing interventions labeled as "anti-aging," such as calorie restriction, exercise, stem cell administration, and senolytics, to provide a down-to-earth evaluation of their current applicability in counteracting aging. Throughout the text, we have maintained a light tone to make it accessible to non-experts in biogerontology, and provide a broad overview for those considering conducting studies, research, or seeking to understand the scientific basis of anti-aging medicine.

Frontiers in sarcopenia: Advancements in diagnostics, molecular mechanisms, and therapeutic strategies

The onset of sarcopenia is intimately linked with aging, posing significant implications not only for individual patient quality of life but also for the broader societal healthcare framework. Early and accurate identification of sarcopenia and a comprehensive understanding of its mechanistic underpinnings and therapeutic targets paramount to addressing this condition effectively. This review endeavors to present a cohesive overview of recent advancements in sarcopenia research and diagnosis. We initially delve into the contemporary diagnostic criteria, specifically referencing the European Working Group on Sarcopenia in Older People (EWGSOP) 2 and Asian Working Group on Sarcopenia (AWGS) 2019 benchmarks. Additionally, we elucidate comprehensive assessment techniques for muscle strength, quantity, and physical performance, highlighting tools such as grip strength, chair stand test, dual-energy X-ray Absorptiometry (DEXA), bioelectrical impedance analysis (BIA), gait speed, and short physical performance battery (SPPB), while also discussing their inherent advantages and limitations. Such diagnostic advancements pave the way for early identification and unequivocal diagnosis of sarcopenia. Proceeding further, we provide a deep-dive into sarcopenia's pathogenesis, offering a thorough examination of associated signaling pathways like the Myostatin, AMP-activated protein kinase (AMPK), insulin/IGF-1 Signaling (IIS), and the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathways. Each pathway's role in sarcopenia mediation is detailed, underscoring potential therapeutic target avenues. From a mechanistic perspective, the review also underscores the pivotal role of mitochondrial dysfunction in sarcopenia, emphasizing elements such as mitochondrial oxidative overload, mitochondrial biogenesis, and mitophagy, and highlighting their therapeutic significance. At last, we capture recent strides made in sarcopenia treatment, ranging from nutritional and exercise interventions to potential pharmacological and supplementation strategies. In sum, this review meticulously synthesizes the latest scientific developments in sarcopenia, aiming to enhance diagnostic precision in clinical practice and provide comprehensive insights into refined mechanistic targets and innovative therapeutic interventions, ultimately contributing to optimized patient care and advancements in the field.

Sustainability of exercise-induced benefits on circulating MicroRNAs and physical fitness in community-dwelling older adults: a randomized controlled trial with follow up

BACKGROUND

Circulating miRNAs (c-miR) have been shown to be potential biomarkers in sarcopenia, but the miRNAs response to aerobic exercise in older people remains inconclusive. We sought to examine the exercise benefits on physical fitness and miRNAs, and to explore the mediating effect of miRNAs on training-induced fitness changes.

METHODS

This controlled trial recruited 58 community-dwelling older adults and randomized them into exercise group (EX) and control group (CON). EX received 8-week supervised moderate intensity cycling training 3x/week. C-miR expression (c-miR-21, c-miR-126, c-miR-146a, c-miR-222), physical fitness (body composition, cardiorespiratory fitness, muscular fitness) and physical activity level (PAL, measured as in daily step counts) were evaluated at baseline, post-training, and post-16-week follow-up. The mediating effect of miRNA expression onto exercise-induced physical fitness change was determined by causal mediation analysis (CMA).

RESULTS

Exercise significantly improved body fat and cardiorespiratory fitness in older people while maintaining muscle mass and strength, and augmented expression of c-miR-126, c-miR-146a, and c-miR-222 for up to 16 weeks post-training. Notably, older people in EX had substantially higher daily step counts than CON throughout the study even after the active training period. However, CMA revealed no significant indirect effect but a potential mediating effect of c-miR-21, but not the rest, onto the body composition, cardiorespiratory fitness, and lower limb strength.

CONCLUSION

An eight-week supervised MICT program promoted a higher level of physical activity up to 16 weeks post-training, which induces better cardiorespiratory fitness and resists decline in muscular measures. C-miRNA, especially c-miR-21, potentially mediates the training effect upon fitness.

Endurance exercise preserves physical function in adult and older male C57BL/6 mice: high intensity interval training (HIIT) versus voluntary wheel running (VWR)

Exercise has been shown to improve physical function, mitigate aspects of chronic disease and to potentially alter the trajectory of age-related onset of frailty and sarcopenia. Reliable and valid preclinical models are necessary to elucidate the underlying mechanisms at the intersection of age, exercise, and functional decline. The purpose of this study was to compare, head to head, the effects of two common pre-clinical models of endurance exercise: high intensity interval training (HIIT) and voluntary wheel running (VWR). The hypothesis was that a prescribed and regimented exercise program, HIIT, would prove to be a superior training method to unregulated voluntary exercise, VWR. To investigate this hypothesis, we evaluated adult (n = 24, designated 10 m, aged 6 months at the beginning of the study, 10 months at its completion) and older adult (n = 18, designated 26 m, aging from 22 months to 26 months over the course of the study) C57BL/6 male mice. These mice were randomly assigned (with selection criteria) to a 13-week program of voluntary wheel running (VWR), high intensity interval training (HIIT), or sedentary control (SED). The functional aptitude of each mouse was determined pre- and post-training using our composite CFAB (comprehensive functional assessment battery) scoring system consisting of voluntary wheel running (volitional exercise and activity rate), treadmill (endurance), rotarod (overall motor function), grip meter (forelimb strength), and inverted cling (whole body strength/endurance). To measure sarcopenia, we tracked body mass, body composition (with EchoMRI), plantar flexor torque (in 10 m), and measured muscle wet mass post-training. Overall, adult CFAB scores decreased while body mass and percent body fat increased as they matured; however, exercise significantly mitigated the changes (p < 0.05) compared to SED. Older adults demonstrated preservation of function (CFAB) and reduced body fat (p < 0.05) compared to SED. To conclude, both types of exercise maintained physical function equally in older mice.

Accelerometer-measured physical activity and sample-based frailty in older women: does pattern really matter?

Background

The relationship between the patterns of physical activity (PA) and frailty, including its various subdomains, remains poorly understood. Therefore, this study aims to investigate the correlations between the patterns of physical activity and frailty and its various subdomains in community-dwelling older women.

Methods

A cross-sectional study investigated the association between physical activity and frailty in 1,099 women aged between 60 to 70 years. Triaxial accelerometers were used to measure bouted PA (a minimum duration of 10 min) and sporadic PA (a duration of <10 min). Fried's frailty phenotype was utilized to evaluate the status of frailty. Data were analyzed using logistic regression and the receiver operating characteristic (ROC) curve.

Results

Bouted moderate-to-vigorous PA (MVPA) and sporadic MVPA were associated with decreased odds of being prefrail and frail, and the optimal cutoff values were 6 and 19.7 for the prefrail stage and 6.6 and 19.4 min/day for the frail stage, respectively. Bouted light PA (LPA) was associated with decreased odds of being prefrail, and the optimal cutoff value was 170.2 min/day. Additionally, bouted and sporadic MVPA were associated with decreased odds of being slow and their optimal cutoff values were 5 and 19.1 min/day, respectively. Sporadic MVPA was associated with decreased odds of exhaustion, and the cutoff was 19.7 min/day. Bouted MVPA and LPA were associated with decreased odds of having low PA, and the cutoff values were 4.4 and 163.2 min/day, respectively.

Conclusion

Any MVPA, regardless of bout duration, could be used as a suitable PA program to improve and prevent frailty in older women, such as bouted MVPA (4-5 times/week) or sporadic MVPA (20 min/day). The improvement effect of bouted and sporadic MVPA on the frailty of older people may not be affected by the subdomain. Additionally, bouted LPA was suitable for the management of prefrailty.

Observational cohort study of highly functioning community-dwelling older adults to assess their sarcopenic status, leisure physical activity, and quality of life over 12-months

Background

The prevalence of sarcopenia varies depending on the cohort evaluated, and the diagnostic criteria used. Older adults with sarcopenia report lower quality of life than their non-sarcopenic peers. Leisure physical activity is reported to have a variable effect on sarcopenic status. Most studies to date, have been done in "vulnerable" populations, with fewer done on independent community-dwelling older adults. None have been done in an Alberta, Canada population.

Objectives

To prospectively evaluate the sarcopenic status of independent community-dwelling older Albertan adults; whether this changed over 12-months; and any association with self-reported leisure activity or quality of life.

Methods

Independent community-dwelling older adults were invited to participate in a 12-month observational study. Assessments were done at baseline, 6 and 12-months for physical function (TUG, SPPB, gait speed, Tinetti, grip strength), muscle mass (DXA, arm and calf circumference), body fat (skinfold, DXA), reported daily exercise (aerobic, resistance), quality of life (EQ5D), and laboratory parameters. European Working Group on Sarcopenia in Older People (EWGSOP) definitions of sarcopenic status were used.

Results

All 50 participants (11 male), were independent of all basic activities of daily living at baseline, and most instrumental activities (some needed assistance with driving or finances). They had an average age of 75.8 (67-90) years, with average MMSE and MoCA cognitive scores of 28.1/30 (20-30) and 24.8/30 (14-30) respectively. Eight participants dropped out prior to their first DXA test. Of the remaining 42, 17 participants (5 male) fulfilled the EWGSOP revised criteria for probable, pre-sarcopenia, or sarcopenia, giving a rate of baseline total sarcopenia of 40.5% in this community-dwelling sample. The majority were pre-sarcopenic (28.6%), and sarcopenia was present only in 7.1%. The total sarcopenia group had a lower BMI (25.6 ± 5.1 versus 29 ± 5, p = 0.01), less body fat by skinfold measurement (36.4 ± 6.5 versus 39.3 ± 8.1, p = 0.01) and lower mid-calf (35.6 ± 3.2 versus 37.6 ± 3.4, p = 0.04) and mid-arm (29.1 ± 2.5 versus 31.9 ± 3.5, p = 0.02) circumferences when compared to their non-sarcopenic peers. After 12-months, 39 participants remained in the study. Of these, the sarcopenic status of 7 improved, 10 declined, with the remaining 56% not changing. There were no statistically significant differences in baseline laboratory parameters between the groups, including 25(OH)D status. But, of the status decliners, 40% had suboptimal 25(OH)D at baseline. Self-reported leisure activity (both total time and frequency) was not associated with sarcopenic status at 12-months. EuroQol -5D was not associated with sarcopenic status.

Conclusions

The rate of sarcopenia was 7.1%, but the total rate of pre, probable and sarcopenia in this highly functioning, community-dwelling older adult cohort was 40.5%. In the majority (75%), there was either no change, or an improvement, in their sarcopenic status over 12-months. There was no association identified with self-reported leisure activity or quality of life in this cohort.

Meta-analysis of the intervention effects of taekwondo on metabolic syndrome indicators

Objective: To quantify the effect of taekwondo as an intervention on the indicators of metabolic syndrome and identify an intervention plan with the optimal effects. Methods: Combining the Cnki.net, Wanfang, PubMed, Web of Science, Embase, KISS, RISS, and DBPIA databases, this paper retrieved relevant references in Chinese, English, and Korean, applied Review Manager 5.4 software to evaluate the methodological quality of the included references according to the Cochrane manual, and utilized Comprehensive Meta-Analysis version 3.7 to perform statistical analyses. Result: A total of 45 references and 1079 related subjects were included in the analysis. The results of the meta-analysis showed that taekwondo has a beneficial effect on all indicators of metabolic syndrome (Hedges' g [effect size] = -0.615, -0.672, -0.497, -0.785, -0.591, and 0.435; p < 0.05). Subgroup analysis revealed the superior intervention effect of taekwondo on metabolic syndrome in women compared to men, middle-aged and elderly compared to other age groups, and abnormal metabolic syndrome indicators compared to normal values. Moreover, the best results were obtained for longer intervention durations-12 weeks-three times per week, for 40-50 min per session. In addition, the combination of intervention types (poomsae, kick, and taekwondo gymnastics) showed optimal effects. The exercise intensity should consider the characteristics of the intervention object and be generally set to medium or high intensity. Conclusion: Taekwondo can effectively improve metabolic syndrome, as evidenced by decreased body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting blood glucose (FBG), and triglyceride (TG) levels and increased high-density lipoprotein cholesterol (HDL-C) level. Taekwondo had the greatest effect on quinquagenarian women with abnormal levels of metabolic syndrome indicators. To maximize the intervention effect of taekwondo on metabolic syndrome, an exercise prescription of high-intensity poomsae, kick, and taekwondo gymnastics performed in 40-50 min sessions, three times weekly for 12 weeks is recommended.

Effects of Aging and Fitness on Hopping Biomechanics

Physical exercise promotes healthy aging and is associated with greater functionality and quality of life. Muscle strength and power are established factors in the ability to perform daily tasks and live independently. Stiffness, for mechanical reasons, is another important constituent of running performance and locomotion. This study aims to analyze the impact of age and training status on one-legged hopping biomechanics and to evaluate whether age-related power decline can be reduced with regular physical exercise. Forty-three male subjects were recruited according to their suitability for one of four groups (young athletes, senior athletes, young controls and senior controls) according to their age (young between 21 and 35, vs. older between 59 and 75) and training status (competing athletes vs. non-physically active). The impact of age and training status on one-legged hopping biomechanics were evaluated using the two-way analysis of variance (ANOVA) method. Significant differences among groups were found for hopping height (p < 0.05), ground contact time (p < 0.05), peak ground reaction force (p < 0.05) and peak power (p < 0.01). No differences among groups were found in ground-phase vertical displacement and vertical stiffness (p > 0.05). Young athletes and older non-physically active people achieved the best and worst performance, respectively. Interestingly, there were not any differences found between young non-physically active people and senior athletes, suggesting that chronic training can contribute to partly offset effects that are normally associated with aging.

Age-related difference in muscle metabolism patterns during upper limb's encircling exercise: a near-infrared spectroscopy study

Aging is usually accompanied by decrease in limb motor function and change in muscle metabolism patterns. However, few studies have investigated the aging effect on muscle hemodynamics of the upper extremity. This study aims to explore the aging effect on muscle metabolism patterns during upper limb's exercise. Twelve middle-aged and elderly subjects and 12 young subjects were recruited, and muscle oxygenation signals from these subjects' biceps brachii muscles were collected during active and passive upper limb's encircling exercise with near-infrared spectroscopy (NIRS). The old group showed stronger muscle hemodynamic metabolism than the young group. The multiscale fuzzy approximate entropy and multiscale transfer entropy analyses indicated higher complexity and stronger interlimb coupling of the muscle oxygenation signals for the old group. Based on the selected muscle metabolism features, the constructed support vector machine model showed a high accuracy rate for classifying the two groups of subjects: 91.6% for the passive mode and 87.5% for the active mode. Our results proved the specific muscle metabolism patterns in the upper limb's exercise for old subjects, promoting the understanding of the aging effect on muscle hemodynamics.

The association of aerobic, resistance, and combined exercises with the handgrip strength of middle-aged and elderly Korean adults: a nationwide cross-sectional study

Background

Handgrip strength (HGS), an indicator of overall muscle strength, is a key component in sarcopenia diagnosis. Although exercise is an effective strategy to prevent sarcopenia, the most appropriate exercise type targeting sarcopenia needs to be established. This study aimed to investigate the relationship between the physical activity (PA) patterns and HGS.

Methods

This was a cross-sectional study using the data from the 7th Korea National Health and Nutrition Examination Survey (2016–2018). The study population included 12,814 adults aged ≥ 40 years. According to the World Health Organization PA guidelines for public health, both aerobic (moderate to vigorous PA ≥ 150 min/week) and resistance exercises (≥ 2 sessions/week) are recommended. Study participants were categorized into one of the four groups depending on their adherence to each of two exercise guidelines (“neither,” “aerobic only,” “resistance only,” and “combined”). By defining normal HGS cutoff values as the lowest quartile of HGS from the population aged 20 years and above, we classified participants as “preserved” HGS group if their HGS was equal to or above the cutoff values. A Poisson regression model was used to calculate adjusted prevalence ratios (APRs) for preserved HGS across the four PA guideline adherences stratified by age and sex groups.

Results

In middle-aged adults, the “combined” exercise group was independently associated with the preserved HGS (male, age 50–59 years, APR = 1.072; male, age 60–69 years, APR = 1.180; female, age 50–59 years, APR = 1.112; female, age 60–69 years, APR = 1.188). For adults aged ≥ 70 years, meeting only aerobic or resistance exercise guidelines showed a positive association with HGS before adjusting for other health-related variables. In males of ≥ 70 years, the APR of preserved HGS was highest in the “combined” exercise group (“resistance only,” APR = 1.459, “combined,” APR = 1.664), while in women aged ≥ 70 years, the significance was lost after adjusting for covariates.

Conclusions

Adults meeting both aerobic and resistance exercise guidelines were associated with the highest prevalence of preserved HGS. Performing both types of exercise might be the most effective way to prevent sarcopenia that should be investigated in future clinical trials.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03293-z.

Fitness tracking reveals task-specific associations between memory, mental health, and physical activity

Physical activity can benefit both physical and mental well-being. Different forms of exercise (e.g., aerobic versus anaerobic; running versus walking, swimming, or yoga; high-intensity interval training versus endurance workouts; etc.) impact physical fitness in different ways. For example, running may substantially impact leg and heart strength but only moderately impact arm strength. We hypothesized that the mental benefits of physical activity might be similarly differentiated. We focused specifically on how different intensities of physical activity might relate to different aspects of memory and mental health. To test our hypothesis, we collected (in aggregate) roughly a century’s worth of fitness data. We then asked participants to fill out surveys asking them to self-report on different aspects of their mental health. We also asked participants to engage in a battery of memory tasks that tested their short and long term episodic, semantic, and spatial memory performance. We found that participants with similar physical activity habits and fitness profiles tended to also exhibit similar mental health and task performance profiles. These effects were task-specific in that different physical activity patterns or fitness characteristics varied with different aspects of memory, on different tasks. Taken together, these findings provide foundational work for designing physical activity interventions that target specific components of cognitive performance and mental health by leveraging low-cost fitness tracking devices.

The Aging Athlete: Paradigm of Healthy Aging

The Exercise Boom of the 1970's resulted in the adoption of habitual exercise in a significant portion of the population. Many of these individuals are defying the cultural norms by remaining physically active and competing at a high level in their later years. The juxtaposition between masters athletes and non-exercisers demonstrate the importance of remaining physically active throughout the lifespan on physiological systems related to healthspan (years of healthy living). This includes ~50% improved maximal aerobic capacity (VO₂max) and enhanced skeletal muscle health (size, function, as well as metabolic and communicative properties) compared to non-exercisers at a similar age. By taking a reductionist approach to VO₂max and skeletal muscle health, we can gain insight into how aging and habitual exercise affects the aging process. Collectively, this review provides a physiological basis for the elite performances seen in masters athletes, as well as the health implications of lifelong exercise with a focus on VO₂max, skeletal muscle metabolic fitness, whole muscle size and function, single muscle fiber physiology, and communicative properties of skeletal muscle. This review has significant public health implications due to the potent health benefits of habitual exercise across the lifespan.

Age Related Changes of Superior Orbicularis Oris Muscle in Terms of Tone and Viscoelastic Properties

OBJECTIVE

To examine the age-related changes in the viscoelastic properties and tone of the superior orbicularis oris muscle by a portablehand-held myotonometer.

METHODS

A total of 128 individuals (65 female, 63 male) who met the inclusion criteria were evaluated. Individuals were divided into 2 groups as under 40 years old (Group 1), and above (Group 2). The viscoelastic properties and muscle tone of orbicularis oris muscle were evaluated bilaterally in supine position with the Myoton PRO (Myoton AS, Estonia) device from the skin overlying the orbicularis oris. The reference point is accepted as the right and left paramedial philtrum dimple. The statistical analysis was performed.

RESULTS

There was no statistically significant difference in the elasticity values of the right and left orbicularis oris muscles of the Group 1 and Group 2 individuals. There was a difference between the groups when the tone and stiffness values of both groups were compared. It was determined that individuals over the age of 40 had higher muscle tone and stiffness. All mechanical properties of the superior orbicularis oris muscle between the male and female individuals in Group 1 were different. The values are higher in the female gender. The elasticity values in both genders in Group 2 were similar. Tone and stiffness parameters were different between genders.

CONCLUSIONS

Myoton PRO can be recommended as an alternative device in the quantitative evaluations of post-operative follow-ups, and pre/post rehabilitation in terms of viscoelastic parameters of the muscle.

Neuroprotective effects of exercise on the aging human neuromuscular system

Human biological aging from maturity to senescence is associated with a gradual loss of muscle mass and neuromuscular function. It is not until very old age (>80 years) however, that these changes often manifest into functional impairments. A driving factor underlying the age-related loss of muscle mass and function is the reduction in the number and quality of motor units (MUs). A MU consists of a single motoneuron, located either in the spinal cord or the brain stem, and all of the muscle fibres it innervates via its peripheral axon. Throughout the adult lifespan, MUs are slowly, but progressively lost. The compensatory process of collateral reinnervation attempts to recapture orphaned muscle fibres following the death of a motoneuron. Whereas this process helps mitigate loss of muscle mass during the latter decades of adult aging, the neuromuscular system has fewer and larger MUs, which have lower quality connections between the axon terminal and innervated muscle fibres. Whether this process of MU death and degradation can be attenuated with habitual physical activity has been a challenging question of great interest. This review focuses on age-related alterations of the human neuromuscular system, with an emphasis on the MU, and presents findings on the potential protective effects of lifelong physical activity. Although there is some discrepancy across studies of masters athletes, if one considers all experimental limitations as well as the available literature in animals, there is compelling evidence of a protective effect of chronic physical training on human MUs. Our tenet is that high-levels of physical activity can mitigate the natural trajectory of loss of quantity and quality of MUs in old age.

Acute, Exercise-Induced Alterations in Cytokines and Chemokines in the Blood Distinguish Physically Active and Sedentary Aging

Aging results in a chronic, proinflammatory state which can promote and exacerbate age-associated diseases. In contrast, physical activity in older adults improves whole body health, protects against disease, and reduces inflammation, but the elderly are less active making it difficult to disentangle the effects of aging from a sedentary lifestyle. To interrogate this interaction, we analyzed peripheral blood collected at rest and postexercise from 68 healthy younger and older donors that were either physically active aerobic exercisers or chronically sedentary. Subjects were profiled for 44 low-abundance cytokines, chemokines, and growth factors in peripheral blood. At rest, we found that regular physical activity had no impact on the age-related elevation in circulating IL-18, eotaxin, GRO, IL-8, IP-10, PDGF-AA, or RANTES. Similarly, there was no impact of physical activity on the age-related reduction in VEGF, EGF, or IL-12 (p70). However, older exercisers had lower resting plasma fractalkine, IL-3, IL-6, and TNF-α compared to sedentary older adults. In contrast to our resting characterization, blood responses following acute exercise produced more striking difference between groups. Physically active younger and older subjects increased over 50% of the analyzed factors in their blood which resulted in both unique and overlapping exercise signatures. However, sedentary individuals, particularly the elderly, had few detectable changes in response to exercise. Overall, we show that long-term physical activity has a limited effect on age-associated changes in basal cytokines and chemokines in the healthy elderly, yet physically active individuals exhibit a broader induction of factors postexercise irrespective of age.

Habitual endurance running does not mitigate age-related differences in gait kinetics

Older adults often walk with smaller ankle joint kinetics and larger hip joint kinetics compared to young adults. These age-related differences have been attributed, in part, to weaker plantarflexor muscles. While it is thought that regular physical activity helps to maintain muscle strength and mobility in older adults, physical activity levels on average decline with age. Therefore, understanding the effect of physical activity level on gait kinetics is an important objective for the management of mobility impairment in older adults. The purpose of this study was determine the effect of habitual endurance running on lower-extremity joint kinetics. 12 male older long-term runners (67 ± 5 yrs., 1.79 ± 0.07 m, 77.3 ± 13.7 kg) and 12 male older non-runners (70 ± 3 yrs., 1.78 ± 0.06 m, 79.68 ± 10.6 kg), performed overground walking trials at 1.3 m/s while kinematic and kinetic data were collected. Participants also performed maximal voluntary contractions at the hip, knee, and ankle joints on an isokinetic dynamometer. Older runners displayed similar ankle plantarflexor strength, similar hip extensor strength, and greater knee extensor strength compared to older non-runners, and walked with similar ankle joint kinetics (p > 0.05), and larger hip joint kinetics compared to older non-runners (p < 0.05). Thus, physical activity, in the form of running at least 20 miles/wk. and training for at least one race per year, did not mitigate the characteristic age-related differences in gait kinetics. Our findings may indicate that age-related differences in lower-extremity gait kinetics are a normal consequence of natural aging.

The Effect of MicroRNA-Mediated Exercise on Delaying Sarcopenia in Elderly Individuals

Sarcopenia is often regarded as an early sign of weakness and is the core element of muscle weakness in elderly individuals. Sarcopenia is closely related to the reduction of exercise, and elderly individuals often suffer from decreased muscle mass and function due to a lack of exercise. At present, studies have confirmed that resistance and aerobic exercise are related to muscle mass, strength and fiber type and to the activation and proliferation of muscle stem cells (MuSCs). Increasing evidence shows that microRNAs (miRNAs) play an important role in exercise-related changes in the quantity, composition and function of skeletal muscle. At the cellular level, miRNAs have been shown to regulate the proliferation and differentiation of muscle cells. In addition, miRNAs are related to the composition and transformation of muscle fibers and involved in the transition of MuSCs from the resting state to the activated state. Therefore, exercise may delay sarcopenia in elderly individuals by regulating miRNAs in skeletal muscle. In future miRNA-focused treatment strategies, these studies will provide valuable information for the formulation of exercise methods and will provide useful and targeted exercise programs for elderly individuals with sarcopenia.

Effects of aging and lifelong aerobic exercise on expression of innate immune components in human skeletal muscle

The purpose of this investigation was to evaluate the effects of aging and lifelong exercise on skeletal muscle components of the innate immune system. Additionally, the effects of an acute resistance exercise (RE) challenge were explored. Three groups of men were studied: young exercisers (YE: n = 10, 25 ± 1 yr; V̇o_2max: 53 ± 3 mL/kg/min; quadriceps size: 78 ± 3 cm²), lifelong aerobic exercisers with a 53 ± 1 yr training history (LLE; n = 21, 74 ± 1 yr; V̇o_2max: 34 ± 1 mL/kg/min; quadriceps size: 67 ± 2 cm²), and old healthy nonexercisers (OH: n = 10, 75 ± 1 yr; V̇o_2max: 22 ± 1 mL/kg/min, quadriceps size: 56 ± 3 cm²). Vastus lateralis muscle biopsies were obtained in the basal state and 4 h after RE (3 × 10 reps, 70% of 1 repetition maximum) to assess Toll-like receptors (TLR)1-10, TLR adaptors (Myd88 and TRIF), and NF-κB pathway components (IκΒα and IKKβ) mRNA expression. Basal TLR3, TLR6, and TLR7 tended to be higher (P ≤ 0.10) with aging (LLE and OH combined). In general, RE increased expression of TLR1 and TLR8 (P ≤ 0.10) and TLR3 and TLR4 (P < 0.05), although TLR3 did not respond in OH. Both TLR adaptors also responded to the exercise bout; these were primarily (Myd88, main effect P ≤ 0.10) or exclusively (TRIF, P < 0.05) driven by the OH group. In summary, aging appears to increase basal expression of some innate immune components in human skeletal muscle, and lifelong aerobic exercise does not affect this age-related increase. An exercise challenge stimulates the expression of several TLRs, while the TLR adaptor response appears to be dysregulated with aging and maintained with lifelong exercise. Partially preserved muscle mass, coupled with a notable immunity profile, suggests lifelong exercisers are likely better prepared for a stress that challenges the immune system.NEW & NOTEWORTHY Findings from this investigation provide novel insight into the effect of aging and lifelong aerobic exercise on structural components of the innate immune system in skeletal muscle of humans. Data presented here suggest aging increases basal expression of select Toll-like receptors (TLRs), and lifelong exercise does not impact this age-related increase. Additionally, acute exercise stimulates gene expression of several TLRs, while the adaptor response is likely dysregulated with aging and maintained with lifelong exercise.

Antioxidants in Sport Sarcopenia

The decline of skeletal muscle mass and strength that leads to sarcopenia is a pathology that might represent an emergency healthcare issue in future years. Decreased muscle mass is also a condition that mainly affects master athletes involved in endurance physical activities. Skeletal muscles respond to exercise by reshaping the biochemical, morphological, and physiological state of myofibrils. Adaptive responses involve the activation of intracellular signaling pathways and genetic reprogramming, causing alterations in contractile properties, metabolic status, and muscle mass. One of the mechanisms leading to sarcopenia is an increase in reactive oxygen and nitrogen species levels and a reduction in enzymatic antioxidant protection. The present review shows the recent experimental models of sarcopenia that explore molecular mechanisms. Furthermore, the clinical aspect of sport sarcopenia will be highlighted, and new strategies based on nutritional supplements, which may contribute to reducing indices of oxidative stress by reinforcing natural endogenous protection, will be suggested.

Sit-to-Stand Kinetics and Correlates of Performance in Young and Older Males

PURPOSE

To compare sit-to-stand (STS) kinetics in young (YM) and older (OM) males and determine correlates of STS performance.

METHODS

YM (n = 15, age = 20.7 ± 2.2 yrs) and OM (n = 15, age = 71.6 ± 3.9 yrs) performed a single STS task as quickly as possible on a force plate and the vertical ground reaction force (VGRF) signal was analyzed. Peak VGRF, as well as peak (100 ms rolling average), early (minimum VGRF to 50% peak VGRF), late (50% peak VGRF to peak VGRF), and overall (minimum VGRF to peak VGRF) rate of force development (RFD) were calculated. Power (absolute and relative) and velocity parameters as well as rate of electromyography rise (RER) were also obtained.

RESULTS

STS time, average power, early RFD, and lower limb lean mass were similar between groups (p > 0.05). All other power, velocity, RFD, and RER measures were lower in OM (p < 0.05; d = 0.41-2.19). Peak VGRF and all RFD measures, except late RFD, were strongly correlated with STS performance in OM, while peak VGRF and peak RFD were only moderately correlated with performance in YM.

CONCLUSIONS

Most kinetic variables, except absolute average power, were diminished in OM, and there was a preferential decrease in late RFD compared to early RFD. Peak VGRF and RFD exhibited stronger correlations with STS time and power in OM compared to YM, and early RFD appears to be more influential for STS performance than late RFD. These findings may be useful for practitioners/clinicians involved in designing interventions aimed at optimizing STS performance in older adults.

Perspective: Pragmatic Exercise Recommendations for Older Adults: The Case for Emphasizing Resistance Training

Optimal health benefits from exercise are achieved by meeting both aerobic and muscle strengthening guidelines, however, most older adults (OAs) do not exercise and the majority of those who do only perform one type of exercise. A pragmatic solution to this problem may be emphasizing a single exercise strategy that maximizes health benefits. The loss of muscle mass and strength at an accelerated rate are hallmarks of aging that, without intervention, eventually lead to physical disability and loss of independence. Additionally, OAs are at risk of developing several chronic diseases. As such, participating in activities that can maintain or increase muscle mass and strength, as well as decrease chronic disease risk, is essential for healthy aging. Unfortunately, there is a widely held belief that adaptations to aerobic and resistance exercise are independent of each other, requiring the participation of both types of exercise to achieve optimal health. However, we argue that this assertion is incorrect, and we discuss crossover adaptations of both aerobic and resistance exercise. Aerobic exercise can increase muscle mass and strength, though not consistently and may be limited to exercise that overloads a particular muscle group, such as stationary bicycling. In contrast, resistance exercise is effective at maintaining muscle health with increasing age, and also has significant effects on cardiovascular disease (CVD) risk factors, type 2 diabetes (T2D), cancer, and mortality. We posit that resistance exercise is the most effective standalone exercise strategy for improving overall health in OAs and should be emphasized in future guidelines.

Nutrient-rich, high-quality, protein-containing dairy foods in combination with exercise in aging persons to mitigate sarcopenia

Sarcopenic declines in muscle mass and function contribute to the risk of falls, reduced mobility, and progression to frailty in older persons. Mitigation of sarcopenia can be achieved by consumption of higher quality protein in sufficient quantities, which current research suggests are greater than the recommended intakes of approximately 0.8 g/kg bodyweight/d. In addition, higher levels of physical activity and participation in exercise to support cardiovascular fitness and musculoskeletal function work additively with protein in attenuating sarcopenia. This narrative review provides evidence to support a recommendation for per-meal protein targets in older persons that are underpinned by knowledge of muscle protein turnover. Based on work examining acute dose-responses of muscle protein synthesis (MPS) to protein, a proposed per-meal target for protein intakes is set at approximately 0.4-0.6 g protein/kg bodyweight/meal for older persons. Habitual patterns of dietary protein intake tend to emphasize a skewed protein distribution, which would not maximize muscle anabolism. Observational studies show that more even patterns of protein intake are associated with increased muscle mass and improved muscle function. A food-based approach to achieving these protein targets would be advantageous, and the nutrient density of the protein-containing foods would be particularly important for older persons. Dairy foods provide high-quality protein and contain several nutrients of concern for older persons. This brief review provides an overview of the science underpinning why dairy foods should be a point of nutritional emphasis for older persons. Practical suggestions are provided for implementation of dairy foods into dietary patterns to meet the protein and other nutrient targets for older persons.

Identifying predictors of upper extremity muscle elasticity with healthy aging

Ultrasound shear wave elastography (SWE) can provide accurate in vivo measurements of the effect of advanced age on muscle elasticity. Our objective was to determine whether passive muscle elasticity was influenced by posture, chronological age, sex, body mass index, and clinical measures of upper extremity function for healthy adults. The dominant arm of 33 male and 33 female participants (ranging from 20 to 89 years old) was examined using a Supersonic Imagine Aixplorer ultrasound SWE system. The mean and standard deviation of shear wave velocity (SWV) was measured from elastography maps for five upper extremity muscles examined at rest: anterior deltoid (AD), biceps brachii (BB), clavicular (CL) and sternocostal (SC) region of the pectoralis major and middle trapezius (MT). Linear mixed models for each muscle were used to assess how SWV was influenced by humeral elevation, chronological age, sex, BMI and three functional measures. All significances are reported at α = 0.05. Humeral elevation influenced shear wave velocity at a statistically significant level for AD, BB, SC and MT (all p < 0.047). Chronological age was a significant predictor of mean SWV for the sternocostal region of the pectoralis major and the middle trapezius (both p < 0.03). These same muscles were also less homogenous (based on their standard deviations) with increased age, particularly for female participants. Performance-based functional assessments of the upper extremity were predictors of mean SWV for the clavicular region of the pectoralis major (all p < 0.04). These results suggest ultrasound SWE has potential utility for assessing age-related changes to muscle elasticity, but these associations were muscle-dependent.

Examining Bone, Muscle and Fat in Middle-Aged Long-Term Endurance Runners: A Cross-Sectional Study

Aerobic exercise training has many known cardiovascular benefits that may promote healthy aging. It is not known if long-term aerobic exercise training is also associated with structural benefits (e.g., lower fat mass, higher areal bone mineral density (BMD) and greater muscle mass). We evaluated these parameters in middle-aged long-term endurance runners compared to sex-, age-, height-, and weight-matched non-running controls. Total and regional lean and fat mass and areal BMD were assessed by dual-energy X-ray absorptiometry. Sagittal magnetic resonance images captured the cross-sectional area and thickness of the lumbar multifidus. Runners (n = 10; all male) had a mean (standard deviation; SD) age of 49 (4) years, height of 178.9 (4.9) cm, weight of 67.8 (5.8) kg, body mass index (BMI) of 21.4 (1.4) kg/m² and had been running 82.6 (27.9) km/week for 23 (13) years. Controls (n = 9) had a mean (SD) age of 51 (5) years, height of 176.0 (5.1) cm, weight of 72.8 (7.1) kg, and BMI of 23.7 (2.1) kg/m². BMI was greater in controls (p = 0.010). When compared to controls on average, runners had a 10 percentage-point greater total body lean mass than controls (p = 0.001) and 14% greater trunk lean mass (p = 0.010), as well as less total body (8.6 kg; p < 0.001), arm (58%; p = 0.002), leg (52%; p < 0.001), trunk (73%; p < 0.001), android (91%; p < 0.001), and gynoid fat mass (64%; p < 0.001). No differences were observed between groups for BMD outcomes or multifidus size. These results underscore the benefits of endurance running to body composition that carry over to middle-age.

Association Between Aerobic Exercise and Handgrip Strength in Adults: A Cross-Sectional Study Based on Data from the Korean National Health and Nutrition Examination Survey (2014-2017)

OBJECTIVES

Handgrip strength is an easy-to-assess indicator of overall muscle strength and can be used to evaluate health status. Although previous studies have reported an increase in grip strength due to aerobic exercise, such a study has not been conducted on Korean participants. This study aimed to investigate the effects of aerobic exercise on handgrip strength and examine the association between these two variables in Korean patients with hypertension or diabetes.

DESIGN

Cross-sectional study.

SETTING

This study used data from the 6th and 7th Korean National Health and Nutrition Examination Survey (2014-2017).

PARTICIPANTS

A total of 19,650 individuals aged ≥19 years who had responded to questionnaires concerning aerobic exercise and handgrip strength were analyzed.

MEASUREMENTS

The relationship between aerobic activity and handgrip strength was examined by logistic regression analysis.

RESULTS

The mean age of individuals in the low muscle strength group was higher than that in the normal muscle strength group. The odds ratio for low handgrip strength was higher in individuals who did not perform aerobic exercise than in those who performed aerobic exercise. Following adjustment for covariates, the odds ratios (95% confidence intervals) for low handgrip strength were 1.415 (0.187-1.688) in the total sample, 1.799 (1.376-2.352) in patients with hypertension, and 1.811 (1.208-2.715) in patients with diabetes.

CONCLUSION

The results of our study indicated a strong association between aerobic exercise and handgrip strength in the Korean population.

Influence of Acute Exercise on DNA Repair and PARP Activity before and after Irradiation in Lymphocytes from Trained and Untrained Individuals

Several studies indicate that acute exercise induces DNA damage, whereas regular exercise increases DNA repair kinetics. Although the molecular mechanisms are not completely understood, the induction of endogenous reactive oxygen species (ROS) during acute exhaustive exercise due to metabolic processes might be responsible for the observed DNA damage, while an adaptive increase in antioxidant capacity due to regular physical activity seems to play an important protective role. However, the protective effect of physical activity on exogenously induced DNA damage in human immune cells has been poorly investigated. We asked the question whether individuals with a high aerobic capacity would have an enhanced response to radiation-induced DNA damage. Immune cells are highly sensitive to radiation and exercise affects lymphocyte dynamics and immune function. Therefore, we measured endogenous and radiation-induced DNA strand breaks and poly (ADP-ribose) polymerase-1 (PARP1) activity in peripheral blood mononuclear cells (PBMCs) from endurance-trained (maximum rate of oxygen consumption measured during incremental exercise V'O2max > 55 mL/min/kg) and untrained (V'O2max < 45 mL/min/kg) young healthy male volunteers before and after exhaustive exercise. Our results indicate that: (i) acute exercise induces DNA strand breaks in lymphocytes only in untrained individuals, (ii) following acute exercise, trained individuals repaired radiation-induced DNA strand breaks faster than untrained individuals, and (iii) trained subjects retained a higher level of radiation-induced PARP1 activity after acute exercise. The results of the present study indicate that increased aerobic fitness can protect immune cells against radiation-induced DNA strand breaks.

Moderate-intensity aerobic exercise improves skeletal muscle quality in older adults

Sarcopenia, age-associated involuntary loss of muscle and strength, can progress to clinically relevant functional decline. Resistance exercise attenuates muscle and strength loss but may not be feasible for some older adults. Aerobic exercise training (AET) improves cardiopulmonary health; however, effects on protein turnover, muscle mass, and strength are less clear. We aimed to determine whether AET improves basal myofibrillar protein synthesis (MPS) and capillarization, promoting hypertrophy and strength. We hypothesized that AET improves strength with increased MPS and capillarization. Older adults were randomized to non-exercise (NON; n = 11, 71.4 ± 4.18 years) or exercise (EX; n = 12, 73.7 ± 4.05 years). EX completed 24 weeks of AET (walking 3×/week, 45 minutes, 70% heart rate reserve); NON remained sedentary. A stable isotope tracer was infused. MPS and capillarization were analyzed from vastus lateralis muscle biopsies. Strength was measured via isokinetic dynamometry. Lean mass was determined with dual-energy X-ray absorptiometry. Basal MPS increased in EX (+50.7%, P = 0.01) along with capillary density (+66.4%, P = 0.03), peak oxygen consumption (+15.8%, P = 0.01), quadriceps strength (+15.1%, P = 0.01), and muscle quality (peak torque divided by leg lean mass, +15.5%, P = 0.01). Lean mass did not change (P > 0.05). AET increases muscle protein turnover and capillarization in older adults, improving muscle quality.

Physical Activity Associated Proteomics of Skeletal Muscle: Being Physically Active in Daily Life May Protect Skeletal Muscle From Aging

Muscle strength declines with aging and increasing physical activity is the only intervention known to attenuate this decline. In order to adequately investigate both preventive and therapeutic interventions against sarcopenia, a better understanding of the biological changes that are induced by physical activity in skeletal muscle is required. To determine the effect of physical activity on the skeletal muscle proteome, we utilized liquid-chromatography mass spectrometry to obtain quantitative proteomics data on human skeletal muscle biopsies from 60 well-characterized healthy individuals (20-87 years) who reported heterogeneous levels of physical activity (not active, active, moderately active, and highly active). Over 4,000 proteins were quantified, and higher self-reported physical activity was associated with substantial overrepresentation of proteins associated with mitochondria, TCA cycle, structural and contractile muscle, and genome maintenance. Conversely, proteins related to the spliceosome, transcription regulation, immune function, and apoptosis, DNA damage, and senescence were underrepresented with higher self-reported activity. These differences in observed protein expression were related to different levels of physical activity in daily life and not intense competitive exercise. In most instances, differences in protein levels were directly opposite to those reported in the literature observed with aging. These data suggest that being physically active in daily life has strong and biologically detectable beneficial effects on muscle.

Nutrition for Special Populations: Young, Female, and Masters Athletes

Adolescent, female, and masters athletes have unique nutritional requirements as a consequence of undertaking daily training and competition in addition to the specific demands of age- and gender-related physiological changes. Dietary education and recommendations for these special population athletes require a focus on eating for long-term health, with special consideration given to “at-risk” dietary patterns and nutrients (e.g., sustained restricted eating, low calcium, vitamin D and/or iron intakes relative to requirements). Recent research highlighting strategies to address age-related changes in protein metabolism and the development of tools to assist in the management of Relative Energy Deficiency in Sport are of particular relevance to special population athletes. Whenever possible, special population athletes should be encouraged to meet their nutrient needs by the consumption of whole foods rather than supplements. The recommendation of dietary supplements (particularly to young athletes) overemphasizes their ability to manipulate performance in comparison with other training/dietary strategies.

Sedentary behaviour, physical activity, and sarcopenia among older adults in the TSHA: isotemporal substitution model

BACKGROUND

The associations between free-living physical activity (PA) and sedentary behaviour (SB) and sarcopenia in older people and its determinants are controversial. Self-reporting, the use of one-size-fits-all cut-points for intensity categorization when using accelerometers and the absence of a clear sarcopenia definition hampered explorations. The aim of this study is to describe the associations between objectively measured PA patterns and sarcopenia and its determinants.

METHODS

Subjects aged >65 with valid accelerometry and sarcopenia-related measures from Toledo Study of Healthy Aging (TSHA) were included. Muscle mass (MM) was estimated by dual-energy X-ray absorptiometry. Handgrip strength (HS) was measured by dynamometry. Physical performance assessment relied on gait speed (GS). Sarcopenia presence was ascertained using Foundation for the National Institutes of Health (FNIH) criteria. PA and SB were estimated by ActiTrainer worn for 1 week and classified into time spent in SB and different PA intensity bands [light PA (LPA) and moderate-to-vigorous PA (MVPA)] using age-specific cut-points. Different multivariate linear and logistic regression models [(i) single-parameter, (ii) partition, and (iii) isotemporal substitution models] were used for estimating associations between PA, SB, and sarcopenia determinants and sarcopenia rates, respectively. All models adjusted for age, sex, co-morbidities (Charlson index), and functional ability (Katz and Lawton indexes).

RESULTS

Five hundred twelve subjects from the TSHA had available data (78.08 ± 5.71 years of age; 54.3% women). FNIH sarcopenia assessment was performed in 497 subjects (23.3% were sarcopenic). In the linear regression, the single-parameter model showed an association between MVPA and all sarcopenia determinants. In the partition model, MVPA was associated with greater MM and GS. The isotemporal substitution showed that reallocating 1 h/day of MVPA displacing SB was associated with greater values in MM [β = 0.014; 95% confidence interval (CI) = 0.004, 0.024; P < 0.01], GS (β = 0.082; 95% CI = 0.054, 0.110; P < 0.001), and HS (β = 0.888; 95% CI = 0.145, 1.631; P < 0.05). In the logistic regression, the single-parameter model yielded a significant association between 1 h/day increase in MVPA and sarcopenia reduction [odds ratio (OR) = 0.522; 95% CI = 0.367, 0.726; P < 0.001], as did the partition model (OR = 0.555; 95% CI = 0.376, 0.799; P < 0.01). The reallocation of 1 h/day SB only yielded a significant lower sarcopenia risk by almost 50% when it was substituted with MVPA, whereas the substitution of 15 min/day yielded a significant lower sarcopenia risk by 15% (P < 0.001) but did not show any association when it was substituted with LPA.

CONCLUSIONS

An increase in MVPA replacing SB and LPA was associated with a reduction in sarcopenia prevalence and better performance across its determinants (MM, GS, and HS). LPA did not show any significant effect.

Combination of Coenzyme Q10 Intake and Moderate Physical Activity Counteracts Mitochondrial Dysfunctions in a SAMP8 Mouse Model

Aging skeletal muscles are characterized by a progressive decline in muscle mass and muscular strength. Such muscular dysfunctions are usually associated with structural and functional alterations of skeletal muscle mitochondria. The senescence-accelerated mouse-prone 8 (SAMP8) model, characterized by premature aging and high degree of oxidative stress, was used to investigate whether a combined intervention with mild physical exercise and ubiquinol supplementation was able to improve mitochondrial function and preserve skeletal muscle health during aging. 5-month-old SAMP8 mice, in a presarcopenia phase, have been randomly divided into 4 groups (n = 10): untreated controls and mice treated for two months with either physical exercise (0.5 km/h, on a 5% inclination, for 30 min, 5/7 days per week), ubiquinol 10 (500 mg/kg/day), or a combination of exercise and ubiquinol. Two months of physical exercise significantly increased mitochondrial damage in the muscles of exercised mice when compared to controls. On the contrary, ubiquinol and physical exercise combination significantly improved the overall status of the skeletal muscle, preserving mitochondrial ultrastructure and limiting mitochondrial depolarization induced by physical exercise alone. Accordingly, combination treatment while promoting mitochondrial biogenesis lowered autophagy and caspase 3-dependent apoptosis. In conclusion, the present study shows that ubiquinol supplementation counteracts the deleterious effects of physical exercise-derived ROS improving mitochondrial functionality in an oxidative stress model, such as SAMP8 in the presarcopenia phase.

CPEO - Like mitochondrial myopathy associated with m.8340G>A mutation

Two patients with an m.8340G>A mitochondrial DNA variant have been reported with one patient showing ptosis, ophthalmoparesis and myopathy at 53% heteroplasmy and another with pigmentary retinopathy, cataracts and sensory neural deafness and slightly higher heteroplasmy (65%). Here we report that higher muscle mutant heteroplasmy (93%) for m.8340G>A is associated with ptosis, ophthalmoparesis and mitochondrial myopathy, thus confirming the initial phenotypic association and showing that heteroplasmy per se does not explain the phenotypic spectrum of disease associated with the m.8340G>A mutation.

Brief Report: Active Ingredients for Adherence to a Tracker-Based Physical Activity Intervention in Older Adults

OBJECTIVES

To identify factors associated with weekly adherence to a 12-week tracker-based activity intervention in older adults.

METHOD

Using generalized linear mixed models in a secondary analysis ( N = 35), we examined factors associated with weekly adherence (defined as wore the Jawbone Up24 tracker for ≥5 days and completed weekly calls). Factors examined included individual characteristics, gave and received virtual support, achieved step goals, barrier and task self-efficacy, and self-comment.

RESULTS

Participants' ( M_age = 61.7, SD_age = 5.7) adherence changed from 86% (Week 1) to 74% (Week 12). Achieved the previous week's goal (β = 1.13, p = .01) and received virtual support (β = 0.01, p = .02) significantly increased the odds of weekly adherence.

DISCUSSION

Achieved step goals and received virtual support were associated with improved adherence to our tracker-based activity intervention, which has promising potential to be translated into the clinical setting to promote active lifestyles.

Exercise and Older Adults

Regular exercise is essential for healthy aging and offers many health benefits, including reduced risk of all-cause mortality, chronic disease, and premature death. Because physical inactivity is prevalent, greater focus is needed on integrating exercise into care plans and counseling, and developing partnerships that support exercise opportunities. Older adults should be as physically active as their abilities and conditions allow. For substantial health benefits, older adults need to do aerobic, muscle-strengthening, and stretching exercises weekly, and balance activities as needed. Appropriate planning must take account of factors such as prescribed medications, nutrition, injuries, hip and knee arthroplasties, and chronic conditions.

Protein and exercise in the prevention of sarcopenia and aging

Aging is associated with a progressive decline in skeletal muscle mass and strength. The decline, known as sarcopenia, could lead to physical disability, poor quality of life, and death. In addition, the older population usually experiences age-related muscle changes that affect muscle mass, muscular strength, and functional abilities. The purpose of this review is to describe the role of protein and exercise in slowing the progression of sarcopenia. It will also discuss whether age-related changes can be attenuated by dietary protein and exercise in the older population. This review will also cover one of the possible mechanisms of how dietary protein and exercise are involved in sarcopenia prevention, as well as the available measurement tools. Based on the findings of this review, the adequate amount of protein required for older men and women needs to be revised and likely be higher. Moreover, studies are required to explore some inconclusive findings concerning sarcopenia in the older population. Further research is required to investigate the following: (1) the safety and effectiveness concerning the consumption of 1.4 g of protein/kg of body weight (or more) in this vulnerable population; (2) the effectiveness of amino acid supplementation in reducing progression of sarcopenia over time through longitudinal studies; (3) the preferred source and timing of protein for the older population to maintain muscular strength and attenuate sarcopenia; (4) exercise interventions, especially those of longer duration, in the attenuation of sarcopenia; (5) other types of exercise and their effects on age-related muscle changes; (6) the mechanism of how protein and exercise prevent muscle loss with aging; and (7) determine the best method to diagnose sarcopenia.

Translating exercise interventions to an in-home setting for seniors: preliminary impact on physical activity and function

AIMS

The purpose of this study is to investigate whether an in-home, individually tailored intervention is efficacious in promoting increases in physical activity (PA) and improvements in physical functioning (PF) in low-active older adults.

METHODS

Participants were randomized to two groups for the 8-week intervention. The enhanced physical activity (EPA) group received individualized exercise programming, including personalized step goals and a resistance band training program, and the standard of care (SoC) group received a general activity goal. Pre- and post-intervention PF measures included choice step reaction time, knee extension/flexion strength, hand grip strength, and 8 ft up and go test completion time.

RESULTS

Thirty-nine subjects completed this study (74.6 ± 6.4 years). Significant increases in steps/day were observed for both the EPA and SoC groups, although the improvements in the EPA group were significantly higher when including only those who adhered to weekly step goals. Both groups experienced significant PF improvements, albeit greater in the EPA group for the 8 ft up and go test and knee extension strength.

CONCLUSION

A low cost, in-home intervention elicited improvements in both PA and PF. Future research is warranted to expand upon the size and scope of this study, exploring dose thresholds (and time frames) for PA to improve PF and strategies to further bolster adherence rates to maximize intervention benefits.

Primary Mitochondrial Disease and Secondary Mitochondrial Dysfunction: Importance of Distinction for Diagnosis and Treatment

Mitochondrial disease refers to a heterogeneous group of disorders resulting in defective cellular energy production due to abnormal oxidative phosphorylation (oxphos). Primary mitochondrial disease (PMD) is diagnosed clinically and ideally, but not always, confirmed by a known or indisputably pathogenic mitochondrial DNA (mtDNA) or nuclear DNA (nDNA) mutation. The PMD genes either encode oxphos proteins directly or they affect oxphos function by impacting production of the complex machinery needed to run the oxphos process. However, many disorders have the 'mitochondrial' phenotype without an identifiable mtDNA or nDNA mutation or they have a variant of unknown clinical significance. Secondary mitochondrial dysfunction (SMD) can be caused by genes encoding neither function nor production of the oxphos proteins and accompanies many hereditary non-mitochondrial diseases. SMD may also be due to nongenetic causes such as environmental factors. In our practice, we see many patients with clinical signs of mitochondrial dysfunction based on phenotype, biomarkers, imaging, muscle biopsy, or negative/equivocal mtDNA or nDNA test results. In these cases, it is often tempting to assign a patient's phenotype to 'mitochondrial disease', but SMD is often challenging to distinguish from PMD. Fortunately, rapid advances in molecular testing, made possible by next generation sequencing, have been effective at least in some cases in establishing accurate diagnoses to distinguish between PMD and SMD. This is important, since their treatments and prognoses can be quite different. However, even in the absence of the ability to distinguish between PMD and SMD, treating SMD with standard treatments for PMD can be effective. We review the latest findings regarding mitochondrial disease/dysfunction and give representative examples in which differentiation between PMD and SMD has been crucial for diagnosis and treatment.

Muscle Decline in Aging and Neuromuscular Disorders - Mechanisms and Countermeasures: Terme Euganee, Padova (Italy), April 13-16, 2016

Not available.

Skeletal muscle homeostasis and plasticity in youth and ageing: impact of nutrition and exercise

Skeletal muscles comprise a substantial portion of whole body mass and are integral for locomotion and metabolic health. Increasing age is associated with declines in both muscle mass and function (e.g. strength‐related performance, power) with declines in muscle function quantitatively outweighing those in muscle volume. The mechanisms behind these declines are multi‐faceted involving both intrinsic age‐related metabolic dysregulation and environmental influences such as nutritional and physical activity. Ageing is associated with a degree of ‘anabolic resistance’ to these key environmental inputs, which likely accelerates the intrinsic processes driving ageing. On this basis, strategies to sensitize and/or promote anabolic responses to nutrition and physical activity are likely to be imperative in alleviating the progression and trajectory of sarcopenia. Both resistance‐ and aerobic‐type exercises are likely to confer functional and health benefits in older age, and a clutch of research suggests that enhancement of anabolic responsiveness to exercise and/or nutrition may be achieved by optimizing modifications of muscle‐loading paradigms (workload, volume, blood flow restriction) or nutritional support (e.g. essential amino acid/leucine) patterns. Nonetheless, more work is needed in which a more holistic view in ageing studies is taken into account. This should include improved characterization of older study recruits, that is physical activity/nutritional behaviours, to limit confounding variables influencing whether findings are attributable to age, or other environmental influences. Nonetheless, on balance, ageing is associated with declines in muscle mass and function and a partially related decline in aerobic capacity. There is also good evidence that metabolic flexibility is impaired in older age.

Physical activity over a decade modifies age-related decline in perfusion, gray matter volume, and functional connectivity of the posterior default-mode network-A multimodal approach

One step toward healthy brain aging may be to entertain a physically active lifestyle. Studies investigating physical activity effects on brain integrity have, however, mainly been based on single brain markers, and few used a multimodal imaging approach. In the present study, we used cohort data from the Betula study to examine the relationships between scores reflecting current and accumulated physical activity and brain health. More specifically, we first examined if physical activity scores modulated negative effects of age on seven resting state networks previously identified by Salami, Pudas, and Nyberg (2014). The results revealed that one of the most age-sensitive RSN was positively altered by physical activity, namely, the posterior default-mode network involving the posterior cingulate cortex (PCC). Second, within this physical activity-sensitive RSN, we further analyzed the association between physical activity and gray matter (GM) volumes, white matter integrity, and cerebral perfusion using linear regression models. Regions within the identified DMN displayed larger GM volumes and stronger perfusion in relation to both current and 10-years accumulated scores of physical activity. No associations of physical activity and white matter integrity were observed. Collectively, our findings demonstrate strengthened PCC-cortical connectivity within the DMN, larger PCC GM volume, and higher PCC perfusion as a function of physical activity. In turn, these findings may provide insights into the mechanisms of how long-term regular exercise can contribute to healthy brain aging.