Responsiveness of muscle size and strength to physical training in very elderly people: a systematic review

Design of the VOILA-intervention study: A 12-week nutrition and resistance exercise intervention in metabolic or mobility compromised Dutch older adults and the response on immune-metabolic, gut and muscle health parameters

BACKGROUND

Exercise and nutrition interventions can slow ageing-induced decline in physiology. However, effects are heterogeneous and usually studied separately per outcome domain. In the VOILA study, we simultaneously study various health outcomes relevant for older adults and the inter-individual heterogeneity in response to a lifestyle intervention.

METHODS

VOILA is a 12-week lifestyle intervention in 3 groups of older adults (≥60 years), with compromised mobility (n=50), compromised metabolic health (n=50), or recovering from total knee replacement (TKR, n=70, of which 20 randomized to standard care only). The intervention includes high-intensity resistance exercise training thrice weekly, nutritional counselling, and nutritional supplements every morning and evening (including 20-25 g whey protein and (evening only) 5.5 g Biotis™ GOS). We measure immune-metabolic, gut health, muscle mass and physical functioning at baseline and after completion of the intervention/standard care. An additional reference group of healthy older adults (n=50) will undergo baseline measurements only.

DISCUSSION

Improvements in various physiological systems are expected, but with differences between groups/individuals. This study will provide insights into how the physiological state of older adults influences the extent of lifestyle-induced health improvements to create better tailored interventions to attenuate biological ageing and improve the health span of subgroups and individuals.

Effects of over 10 weeks of resistance training on muscle and bone mineral density in older people with sarcopenia over 70 years old: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

We aimed to examine the effects of more than 10 weeks of resistance training (RT) on muscle structure, muscle function, and bone mineral density (BMD) in older people with sarcopenia over 70 years old METHODS: PubMed, Web of Science, Embase, MEDLINE, Cochrane Library, and CINAHL databases were searched for randomized controlled trials. Standardized mean difference (MD) or standard mean difference (SMD) was used to pool the effect of the RT intervention RESULTS: Thirteen studies with 2080 older adults with sarcopenia were included. Resistance exercise significantly affected handgrip strength (MD = 1.67 kg; P = 0.02) and isometric muscle strength (standard mean difference [SMD] = 0.53; P = 0.02). Significant differences in chair stand test (SMD = 0.40; P = 0.02) and skeletal muscle mass index (mean difference [MD] = 1.67 kg/m2; P = 0.0002) were found between the RT and control groups CONCLUSION: More than 10 weeks of RT has beneficial effects on muscle but no favorable effect on BMD in older people with sarcopenia over 70 years old.

Increased knee-extension strength and steps per day after a novel post-hospitalization rehabilitative program in older adults (65+): Secondary analyses of a randomized controlled single-blinded trial using an expanded sample size

INTRODUCTION

Older adults are at risk of developing new or worsened disability when hospitalized for acute medical illness. This study is a secondary analysis of the STAND-Cph trial on the effect of a simple strength training intervention initiated during hospitalization and continued after discharge. We investigated the between-group difference in change in functional performance outcomes, the characteristics of patients who experienced a relevant effect of the intervention, and the characteristics of those who were compliant with the intervention, using an expanded sample size as protocolized.

METHODS

The STAND-Cph was a randomized controlled trial conducted at a major Danish university hospital. Acutely admitted older adult patients (65+) from the Emergency Department were randomized to the intervention group receiving progressive strength training and a protein supplement during and after hospitalization (12 sessions over 4 weeks) or control group receiving usual care. The primary outcome was the de Morton Mobility Index assessed at baseline and 4 weeks after discharge. The secondary outcomes were 24-h mobility (assessed by ActivPAL accelerometers), isometric knee-extension strength, 30 s. sit-to-stand performance, and habitual gait speed.

RESULTS

Between September 2013 and September 2018, a total of 158 patients were included and randomized to either the intervention group (N = 80; mean age 79.9 ± 7.6 years) or the control group (N = 78; mean age 80.8 ± 7.4 years). We found no significant between-group difference in change in our primary outcome (p > 0.05). Both the intention-to-treat (difference in change 0.14 Nm/kg (95 % CI 0.03;0.24), p = 0.01) and the per protocol (difference in change 0.16 Nm/kg (95 % CI 0.04;0.29), p = 0.008) analyses showed that between baseline and 4 weeks, knee-extension strength increased significantly more in the intervention group than in the control group. Also, the per protocol analysis showed that the intervention group increased their daily number of steps significantly more than the control group (difference in change 1088 steps (95 % CI 44; 2132); p = 0.04). When examining subgroups of patients, we found no significant differences neither between those who experienced a clinically relevant improvement in the de Morton Mobility Index and those who did not, nor between those who were compliant and those who were not.

CONCLUSION

This exploratory analysis indicates that while simple progressive strength training and protein supplementation does not improve functional performance assessed by the de Morton Mobility Index, it can benefit specific facets of physical activity and muscle strength among geriatric patients.

Skeletal muscle adaptations following eccentric contractions are not mediated by keratin 18

The molecular mechanisms that drive muscle adaptations after eccentric exercise training are multifaceted and likely impacted by age. Previous studies have reported that many genes and proteins respond differently in young and older muscles following training. Keratin 18 (Krt18), a cytoskeletal protein involved in force transduction and organization, was found to be upregulated after muscles performed repeated bouts of eccentric contractions, with higher levels observed in young muscle compared with older muscle. Therefore, the purpose of this study was to determine if Krt18 mediates skeletal muscle adaptations following eccentric exercise training. The anterior crural muscles of Krt18 knockout (KO) and wild-type (WT) mice were subjected to either a single bout or repeated bouts of eccentric contractions, with isometric torque assessed across the initial and final bouts. Functionally, Krt18 KO and WT mice did not differ prior to performing any eccentric contractions (P ≥ 0.100). Muscle strength (tetanic isometric torques) and the ability to adapt to eccentric exercise training were also consistent across strains at all time points (P ≥ 0.169). Stated differently, immediate strength deficits and the recovery of strength following a single bout or multiple bouts of eccentric contractions were similar between Krt18 KO and WT mice. In summary, the absence of Krt18 does not impede the muscle's ability to adapt to repeated eccentric contractions, suggesting it is not essential for exercise-induced remodeling.NEW & NOTEWORTHY The molecular processes that underlie the changes in skeletal muscle following eccentric exercise training are complex and involve multiple factors. Our findings indicate that Krt18 may not play a significant role in muscle adaptations following eccentric exercise training, likely due to its low expression in skeletal muscle. These results underscore the complexity of the molecular mechanisms that contribute to muscle plasticity and highlight the need for further research in this area.

Diet, Food Intake, and Exercise Mixed Interventions (DEMI) in the Enhancement of Wellbeing among Community-Dwelling Older Adults in Japan: Systematic Review and Meta-Analysis of Randomized Controlled Trials

This systematic review and meta-analysis discusses the available data on the efficacy of diet, food intake, and exercise mixed interventions (DEMI) for community-dwelling older adults in Japan and assesses the evidence level. We searched the literature regarding the research questions using electronic and hand-searching methods. To ensure the reliability and quality of the evidence, we used the Cochrane risk of bias tool and GRADE system. All studies included DEMI; other interventions included group activities, health education, and community participation. All interventions were categorized into three classifications, namely "Diet and food intake", "Exercise", and "Other". Programs included lectures, practical exercises, group activities, consulting, and programs that could be implemented at home. By comparing groups and measuring outcomes at various time points, most studies reported positive results regarding the impact of the interventions. Specifically, usual gait speed, Food Frequency Questionnaire Score, and Diet Variety Score demonstrated significant improvement. Additionally, three studies demonstrated improvement in frailty. This review suggests that DEMI resulted in improvements in some outcome variables. However, the efficacy of all variables was not fully examined. The results of the meta-analysis revealed positive outcomes for some variables, although the evidence level for these outcomes was considered moderate.

Exploring the utility of bedside tests for predicting cardiorespiratory fitness in older adults

Objectives

Cardiorespiratory fitness (CRF) declines with advancing and has also, independent of age, been shown to be predictive of all-cause mortality, morbidity, and poor clinical outcomes. In relation to the older patient, there is a particular wealth of evidence highlighting the relationship between low CRF and poor surgical outcomes. Cardiopulmonary exercise testing (CPET) is accepted as the gold-standard measure of CRF. However, this form of assessment has significant personnel and equipment demands and is not feasible for those with certain age-associated physical limitations, including joint and cardiovascular comorbidities. As such, alternative ways to assess the CRF of older patients are very much needed.

Methods

Sixty-four participants (45% female) with a median age of 74 (65-90) years were recruited to this study via community-based advertisements. All participants completed three tests of physical function: (1) a step-box test; (2) handgrip strength dynamometry; and (3) a CPET on a cycle ergometer; and also had their muscle architecture (vastus lateralis) assessed by B-mode ultrasonography to provide measures of muscle thickness, pennation angle, and fascicle length. Multivariate linear regression was then used to ascertain bedside predictors of CPET parameters from the alternative measures of physical function and demographic (age, gender, body mass index (BMI)) data.

Results

There was no significant association between ultrasound-assessed parameters of muscle architecture and measures of CRF. VO2peak was predicted to some extent from fast step time during the step-box test, gender, and BMI, leading to a model that achieved an R 2 of 0.40 (p < 0.001). Further, in aiming to develop a model with minimal assessment demands (i.e., using handgrip dynamometry rather than the step-box test), replacing fast step time with non-dominant HGS led to a model which achieved an R 2 of 0.36 (p < 0.001). Non-dominant handgrip strength combined with the step-box test parameter of fast step time and BMI delivered the most predictive model for VO2peak with an R 2 of 0.45 (p < 0.001).

Conclusions

Our findings show that simple-to-ascertain patient characteristics and bedside assessments of physical function are able to predict CPET-derived CRF. Combined with gender and BMI, both handgrip strength and fast step time during a step-box test were predictive for VO2peak. Future work should apply this model to a clinical population to determine its utility in this setting and to explore if simple bedside tests are predictive of important clinical outcomes in older adults (i.e., post-surgical complications).

Impacts of whole-body vibration on denervated skeletal-muscle atrophy in rats

Whole-body vibration has been considered as a countermeasure against muscle atrophy. However, its effects on muscle atrophy are poorly understood. We evaluated the effects of whole-body vibration on denervated skeletal muscle atrophy. Whole-body vibration was performed on rats from Day 15 to 28 after denervation injury. Motor performance was evaluated using an inclined-plane test. Compound muscle action potentials of the tibial nerve were examined. Muscle wet weight and muscle fiber cross-sectional area were measured. Myosin heavy chain isoforms were analyzed in both muscle homogenates and single myofibers. Whole-body vibration resulted in a significantly decreased inclination angle and muscle weight, but not muscle fiber cross-sectional area of fast-twitch gastrocnemius compared to denervation only. In denervated gastrocnemius, a fast-to-slow shift was observed in myosin heavy chain isoform composition following whole-body vibration. There were no significant changes in muscle weight, muscle fiber cross-sectional area, and myosin heavy chain isoform composition in denervated slow-twitch soleus. These results imply that whole-body vibration does not promote recovery of denervation-induced muscle atrophy.

Adaptability to eccentric exercise training is diminished with age in female mice

The ability of skeletal muscle to adapt to eccentric contractions has been suggested to be blunted in older muscle. If eccentric exercise is to be a safe and efficient training mode for older adults, preclinical studies need to establish if older muscle can effectively adapt and if not, determine the molecular signatures that are causing this impairment. The purpose of this study was to quantify the extent age impacts functional adaptations of muscle and identify genetic signatures associated with adaptation (or lack thereof). The anterior crural muscles of young (4 mo) and older (28 mo) female mice performed repeated bouts of eccentric contractions in vivo (50 contractions/wk for 5 wk) and isometric torque was measured across the initial and final bouts. Transcriptomics was completed by RNA-sequencing 1 wk following the fifth bout to identify common and differentially regulated genes. When torques post eccentric contractions were compared after the first and fifth bouts, young muscle exhibited a robust ability to adapt, increasing isometric torque 20%-36%, whereas isometric torque of older muscle decreased up to 18% (P ≤ 0.047). Using differential gene expression, young and older muscles shared some common transcriptional changes in response to eccentric exercise training, whereas other transcripts appeared to be age dependent. That is, the ability to express particular genes after repeated bouts of eccentric contractions was not the same between ages. These molecular signatures may reveal, in part, why older muscles do not appear to be as adaptive to exercise training as young muscles.NEW & NOTEWORTHY The ability to adapt to exercise training may help prevent and combat sarcopenia. Here, we demonstrate young mouse muscles get stronger whereas older mouse muscles become weaker after repeated bouts of eccentric contractions, and that numerous genes were differentially expressed between age groups following training. These results highlight that molecular and functional plasticity is not fixed in skeletal muscle with advancing age, and the ability to handle or cope with physical stress may be impaired.

Vibration therapy to improve pain and function in patients with chronic low back pain: a systematic review and meta-analysis

BACKGROUND

Vibration therapy (VT), a treatment of musculoskeletal disorders, has been developed for clinical applications in the past decade. However, its effect on relieving chronic low back pain (CLBP) and improving lumbar function is still illusive, lacking sufficient evidence-based medical data.

OBJECTIVE

This systematic review aimed to evaluate the efficacy of vibration therapy on pain and function in people with CLBP.

METHODS

PubMed, Cochrane Library, Web of Science, Embase, CNKI, Wanfang Date, VIP, and CBM were applied to search for clinical randomized controlled trials (RCTs) on vibration therapy for people with CLBP. The electronic databases were searched from the establishment of the database until July 1, 2023. Two researchers assessed the quality of the included studies and extracted data. The outcome indicators included the pain intensity index, Oswestry dysfunction index (ODI) score, and Roland-Morris dysfunction questionnaire (RMDQ) score. GRADE was used to evaluate the certainty of evidence of each outcome indicator. The meta-analysis was conducted using RevMan 5.3 software.

RESULTS

Fourteen papers met the inclusion criteria with 860 subjects (VT group n = 432 and control group n = 428). VT for patients with CLBP reduced the pain intensity index [SMD = - 0.71, 95% CI (- 1.02, - 0.39), I2 = 76%, P < 0.0001], the ODI score value [MD = - 4.24, 95% CI (- 8.10, - 0.38), I2 = 88%, P = 0.03], and the RMDQ score value [MD = - 2.21, 95% CI (- 3.41, - 1.01), I2 = 0%, P = 0.0003]. Subgroup analysis displayed that the pain intensity index was lower in the whole-body vibration (WBV) group than in the control group [SMD = - 0.49, 95% CI (- 0.79, - 0.19), I2 = 58%, P = 0.001] and the local vibration (LV) group [SMD = - 1.07, 95% CI (- 1.60, - 0.53), I2 = 76%, P < 0.0001]. The ODI scores in the WBV group were lower than those in the control group [MD = - 3.30, 95% CI (- 5.76, - 0.83), I2 = 36%, P = 0.009]. There was no statistically significant difference in ODI scores between the LV group and the control group [MD = - 5.78, 95% CI (- 16.23, 4.66), I2 = 97%, P = 0.28].

CONCLUSION

The data from this study suggest that VT can reduce pain and improve lumbar function in patients with CLBP. However, we still need to carefully interpret the results of this study, as the certainty of evidence was low, and the clinical relevance of the results is questionable. Further RCTs are needed in the future to ascertain this.

Translation, cross-cultural adaption, validity and reliability of a composite physical function scale for adults aged 65 + years in a Danish context

BACKGROUND

To prevent or postpone dependence on help in everyday activities, early identification of adults aged 65 + years at risk of functional decline or with progressing functional decline is essential. The American Composite Physical Function (CPF) scale was developed to detect and prevent this age-conditioned decline. In this study, the aim was to translate and adapt the scale into a Danish version and assess the validity and reliability in Danish adults aged 65 + years.

METHODS

A forward-backward translation procedure was used, followed by an expert panel review to finalise the Danish version of the CPF scale. In the subsequent pre-test, three-step cognitive interviews and hypotheses testing were performed to evaluate the validity, and a test-retest was done to assess reliability.

RESULTS

In the pre-test, 47 adults participated in three-step cognitive interviews, and 45 adults answered an online version of the scale. In terms of content validity, the scale was relevant and easy to answer, although many informants skipped the instruction to the questionnaire, which may negatively impact face validity. Construct validity showed a significant difference in CPF scores in adults aged 65 + years by residence and activity level and a decreasing CPF score with increasing age. The reliability test showed an excellent kappa (0.92).

CONCLUSION

The scale covering daily activities helps to identify adults aged 65 + years with reduced physical functions or at risk of loss of independence. Further research is needed to assess the CPF predictive value for adults aged 65 + years at risk of or with a progressing physical decline.

Fat infiltration and muscle hydration improve after high-intensity resistance training in women with sarcopenia. A randomized clinical trial

BACKGROUND

Resistance training is recommended for preventing sarcopenia, but the benefits for the quality and quantity of muscle mass are uncertain.

OBJECTIVE

To assess the effects of high-intensity resistance training (HIRT) on clinical and magnetic resonance imaging (MRI) parameters in women with sarcopenia.

METHODS

A researcher-blinded randomized clinical trial was conducted. Community-dwelling older women with sarcopenia were randomized to six months of HIRT or a control group (CG). Body composition was assessed with bioimpedance equipment, and participants underwent strength and functional performance tests (short physical performance battery [SPPB] and gait speed). MRI scans of the thigh were taken to quantify muscle mass and quality.

RESULTS

Thirty-eight women completed the study (20 in the HIRT group). Sarcopenia remitted in 50 % of the HIRT group. HIRT elicited a significant group × time interaction effect for muscle mass (p = 0.027; Ƞ² = 0.129), muscle mass index (p = 0.023; Ƞ² = 0.135), fat mass (p = 0.048; Ƞ² = 0.103) and all strength variables (p < 0.05; Ƞ² > 0.120). Moreover, the HIRT group obtained higher scores on the SPPB (mean difference [MD] 1.2; p = 0.005) and the 5 times sit-to-stand test (MD = 0.7; p = 0.009). Regarding MRI parameters, infiltrated microscopic fat decreased significantly (HIRT: MD = -0.01; p < 0.05), while hydration (T2) decreased in the CG (MD = 3.6 ms; p = 0.053) at six months. There were significant between-group differences at six months for water diffusion (HIRT: 1.09 × 10^-3 mm²/s vs CG: 1.26 × 10^-3 mm²/s) and total muscular volume (HIRT: 832.4 L vs CG: 649.2 L).

CONCLUSIONS

HIRT led to the remission of sarcopenia in half of the older women, as seen in muscle mass, strength, and functional performance and MRI biomarkers, with significant increases in muscle quality. REGISTERED IN CLINICALTRIALS.GOV: NCT03834558.

Whole Body Vibration: A Valid Alternative Strategy to Exercise?

Several studies agree that mechanical vibration can induce physiological changes at different levels, improving neuromuscular function through postural control strategies, muscle tuning mechanisms and tonic vibration reflexes. Whole-body vibration has also been reported to increase bone mineral density and muscle mass and strength, as well as to relieve pain and modulate proprioceptive function in patients with osteoarthritis or lower back pain. Furthermore, vibratory training was found to be an effective strategy for improving the physical performance of healthy athletes in terms of muscle strength, agility, flexibility, and vertical jump height. Notably, several benefits have also been observed at the brain level, proving to be an important factor in protecting and/or preventing the development of age-related cognitive disorders. Although research in this field is still debated, certain molecular mechanisms responsible for the response to whole-body vibration also appear to be involved in physiological adaptations to exercise, suggesting the possibility of using it as an alternative or reinforcing strategy to canonical training. Understanding these mechanisms is crucial for the development of whole body vibration protocols appropriately designed based on individual needs to optimize these effects. Therefore, we performed a narrative review of the literature, consulting the bibliographic databases MEDLINE and Google Scholar, to i) summarize the most recent scientific evidence on the effects of whole-body vibration and the molecular mechanisms proposed so far to provide a useful state of the art and ii) assess the potential of whole-body vibration as a form of passive training in place of or in association with exercise.

Effects of supervised high-intensity hardstyle kettlebell training on grip strength and health-related physical fitness in insufficiently active older adults: the BELL pragmatic controlled trial

The Ballistic Exercise of the Lower Limb (BELL) trial examined the efficacy and safety of a pragmatic hardstyle kettlebell training program in older adults. Insufficiently active men and women aged 59–79 years, were recruited to a 6-month repeated measures study, involving 3-months usual activity and 3-months progressive hardstyle kettlebell training. Health-related physical fitness outcomes included: grip strength [GS], 6-min walk distance [6MWD], resting heart rate [HR], stair-climb [SC], leg extensor strength [LES], hip extensor strength [HES], Sit-To-Stand [STS], vertical jump [CMVJ], five-times floor transfer [5xFT], 1RM deadlift, body composition (DXA), attendance, and adverse events. Sixteen males (68.8 ± 4.6 yrs, 176.2 ± 7.8 cm, 90.7 ± 11.0 kg, 29.2 ± 2.6 kg/m²) and sixteen females (68.6 ± 4.7 yrs, 163.9 ± 5.4 cm, 70.4 ± 12.7 kg, 26.3 ± 4.9 kg/m²) were recruited. Compliance with the supervised exercise program was very high (91.5%). Kettlebell training increased GS (R: MD = 7.1 kg 95% CI [4.9, 9.3], L: MD = 6.3 kg 95% CI [4.1, 8.4]), 6MWD (41.7 m, 95% CI [17.9, 65.5]), 1RM (16.2 kg, 95% CI [2.4, 30.0]), 30 s STS (3.3 reps, 95% CI [0.9, 5.7]), LES (R: MD = 61.6 N, 95% CI [4.4, 118.8]), HES (L: MD = 21.0 N,95% CI [4.2,37.8]), appendicular skeletal lean mass (MD = 0.65 kg, 95% CI [0.08, 1.22]), self-reported health change (17.1%, 95% CI [4.4, 29.8]) and decreased SC time (2.7 s, 95% CI [0.2, 5.2]), 5xFT time (6.0 s, 95% CI [2.2, 9.8]) and resting HR (7.4 bpm, 95% CI [0.7, 14.1]). There were four non-serious adverse events. Mean individual training load for group training sessions during the trial was 100,977 ± 9,050 kg. High-intensity hardstyle kettlebell training was well tolerated and improved grip strength and measures of health-related physical fitness in insufficiently active older adults.

Trial registration: Prospectively registered: 20/08/2019, Australian New Zealand Clinical Trials Registry (ACTRN12619001177145).

Introducing Progressive Strength Training Program in Singapore's Elder Care Settings

The use of progressive strength training among the elderly has become an accepted part of evidence-based practice for preventive and rehabilitative care. Exercise is undoubtedly one of the pillars for resilient aging. While research has shown impressive outcomes from strength training, the challenge remains to get elderly persons to exercise. Here we describe a Finnish-Singaporean cross-national project that provides a unique opportunity to evaluate the implementation of strength training in settings where it had previously not been applied. We report from the first 2 years of implementation using assessment data and surveys directed to frontline therapists responsible for the implementation. The strength training concept was progressively implemented in 24 elder care locations in Singapore including residential homes, day rehab/care centers, and senior activity centers. Each location was provided with training, support, gym equipment and technology solutions. It remained for individual sites to enroll elderly to the program, to perform assessments, and to direct the progressive strength training. Based on data from the first 2 years of implementation, improvements in lower body muscle strength were found in Leg Curl (ave 11.1–48.8%), Leg Extension (ave 10.2–24.0%) and Hip Abduction/Hip Adduction (ave 7.0–15.8%). Of the trained therapists, 95% strongly agreed or agreed to some extent that the implementation had been successful. The practice-based evidence from the project has demonstrated that it is feasible to implement progressive strength training in real life settings, using technology. While the implementation initially required handholding and support, the approach yielded consistent improvement rates in muscle strength comparable to results from randomized clinical trials (meta-analysis studies). Significant improvement rates in muscle strength were found in all three types of sites, demonstrating that gym training can be employed broadly in elder care. The Senior Activity Centers offer an interesting model for reaching seniors with preventive actions at an early stage. The data support a 3-month training as an effective intervention of introducing strength training in elder care settings, promoting healthy aging.

Rate of Force Development Is Related to Maximal Force and Sit-to-Stand Performance in Men With Stages 3b and 4 Chronic Kidney Disease

Introduction: The primary aims of the present study were to assess the relationships of early (0–50 ms) and late (100–200 ms) knee extensor rate of force development (RFD) with maximal voluntary force (MVF) and sit-to-stand (STS) performance in participants with chronic kidney disease (CKD) not requiring dialysis.

Methods: Thirteen men with CKD (eGFR = 35.17 ±.5 ml/min per 1.73 m², age = 70.56 ±.4 years) and 12 non-CKD men (REF) (eGFR = 80.31 ± 4.8 ml/min per 1.73 m², age = 70.22 ±.9 years) performed maximal voluntary isometric contractions to determine MVF and RFD of the knee extensors. RFD was measured at time intervals 0–50 ms (RFD₀₋₅₀) and 100–200 ms (RFD_100−200). STS was measured as the time to complete five repetitions. Measures of rectus femoris grayscale (RF GSL) and muscle thickness (RF MT) were obtained via ultrasonography in the CKD group only. Standardized mean differences (SMD) were used to examine differences between groups. Bivariate relationships were assessed by Pearson's product moment correlation.

Results: Knee extensor MVF adjusted for body weight (CKD=17.14 ±.1 N·kg^0.67, REF=21.55 ±.3 N·kg^0.67, SMD = 0.79) and STS time (CKD = 15.93 ±.4 s, REF = 12.23 ±.7 s, SMD = 1.03) were lower in the CKD group than the REF group. Absolute RFD_100−200 was significantly directly related to adjusted MVF in CKD (r = 0.56, p = 0.049) and REF (r = 0.70, p = 0.012), respectively. STS time was significantly inversely related to absolute (r = −0.75, p = 0.008) and relative RFD₀₋₅₀ (r = −0.65, p = 0.030) in CKD but not REF (r = 0.08, p = 0.797; r = 0.004, p = 0.991). Significant inverse relationships between RF GSL adjusted for adipose tissue thickness and absolute RFD_100−200 (r =−0.59, p = 0.042) in CKD were observed.

Conclusion: The results of the current study highlight the declines in strength and physical function that occur in older men with CKD stages 3b and 4 not requiring dialysis. Moreover, early RFD was associated with STS time in CKD while late RFD was associated MVF in both CKD and REF.

Clinical Trial Registration: ClinicalTrials.gov, identifier: NCT03160326 and NCT02277236.

Exercise therapy for sarcopenia in rheumatoid arthritis: A meta-analysis and meta-regression of randomized controlled trials

OBJECTIVE

Rheumatoid arthritis and age are associated with high sarcopenia risk. Exercise is an effective treatment for preventing muscle mass loss in older adult populations. It remains unclear whether exercise affects muscle mass in people with rheumatoid arthritis. Thus, this meta-analysis investigated the effect of exercise on muscle mass gain in patients with rheumatoid arthritis.

DATA SOURCES

PubMed, EMBASE, the Cochrane Library, the Physiotherapy Evidence Database (PEDro), the China Knowledge Resource Integrated Database, and Google Scholar were systematically searched until June 2021.

METHODS

The present study was conducted according to the guidelines recommended by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. Randomized controlled trials (RCTs) that reported the effects of exercise on muscle mass for rheumatoid arthritis were identified. The included RCTs were subject to meta-analysis and risk of bias assessment. Subgroup and random-effects meta-regression analyses were performed to identify any heterogeneity (I²) of treatment effects across studies.

RESULTS

We included nine RCTs with a median PEDro score of 6/10 (range: 4/10-8/10). The weighted mean effect size for muscle mass was 0.77 (95% CI: 0.30-1.24; P = 0.001; I² = 77%). Meta-regression analyses indicated that the disease duration significantly explained variance of treatment effects across studies (β = -0.006, R² = 69.7%, P = 0.005).

CONCLUSIONS

Exercise therapy effectively increased muscle mass in patients with rheumatoid arthritis. Treatment effects may be attenuated in those who have had rheumatoid arthritis for a relatively long time.

Effects of resistance training on muscle strength, insulin-like growth factor-1, and insulin-like growth factor-binding protein-3 in healthy elderly subjects: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Findings regarding the effects of resistance training (RT) on muscle strength, serum level of IGF-1, and its binding proteins are contradictory. To resolve this contradiction, we performed a systematic review and meta-analysis to investigate the effects of RT on muscle strength, the levels of serum IGF-1, and IGF-binding protein-3 in the elderly and aged.

MATERIALS AND METHODS

The PubMed, CINAHL, Medline, Google Scholar, and Scopus databases and reference lists of included studies were systematically searched to identify randomized controlled trials (RCTs) comparing subjects who underwent RT and control individuals up to May 15, 2020. This study was performed following the Preferred Items for Reporting of Systematic Reviews and Meta-Analyses guidelines. We identified and analyzed 11 eligible trials in this meta-analysis.

RESULTS

Pooled data displayed an overall significant elevation in IGF-1 (mean difference (MD): 17.34 ng/ml; 95% confidence interval (CI): 7.23, 27.46) and in muscle strength in leg press (SMD: 0.82; 95% CI: 0.30, 1.34) and bench press (SMD: 0.82; 95% CI: 0.42, 1.23) following RT. By contrast, the pooled estimate showed a non-significant elevation in IGFBP-3 (MD: 0.13 ng/ml; 95% CI: - 39.39, 39.65). Subgroup analysis revealed that the elevation in serum IGF-1 levels after RT was significant only in women (MD: 19.30 ng/ml); moreover, it increased after intervention durations of both > 12 weeks (MD: 21.98 ng/ml) and of ≤ 12 weeks (MD: 15.31 ng/ml).

CONCLUSION

RT was associated with elevated muscle strength. Moreover, RT was correlated with increased serum levels of IGF-1 among women and among those who received the training for ≤ 12 weeks or > 12 weeks. Further studies are required to elucidate the mechanisms underlying the impact of RT on IGF-1, IGFBP-3, and muscle strength.

Exercise in patients with hip osteoarthritis - effects on muscle and functional performance: A randomized trial

Background: It is believed that clinical management of osteoarthritis should address muscle weakness to improve physical function and prevent disability and frailty.Objectives: This sub-study investigated the effects of supervised progressive resistance training (RT), supervised Nordic Walking (NW), and unsupervised home-based exercise (HBE) on muscle and functional performance; and associations between these exercise-induced changes in persons with hip osteoarthritis.Methods: Forty-two patients with hip osteoarthritis were recruited from a larger RCT (NCT01387867). All the groups (RT, n = 15; NW, n = 12; HBE, n = 15) exercised 1 h 3 times/week for 4 months. Quadriceps cross-sectional area (QCSA, MRI-determined); quadriceps strength (QMVC); leg extensor power (LEP); functional performance (chair stands (30sCS); stair climbs (TSC); and 6-minute walk (6MWT)) were assessed at baseline and 4 months.Results: Per protocol analyses (one-way ANOVA and Bonferroni test) showed significant between-group differences for improvements in QCSA in the most symptomatic leg favoring RT versus NW (2.3 cm², 95% CI [0.6, 3.9]) and HBE (2.3 cm² [0.8, 3.9]); and 30sCS (1.8 repetitions [0.2-3.3]), and 6MWT (35.1 m [3.5-66.7]) favoring NW versus HBE. Associations existed between exercise-induced changes in QCSA and QMVC (r = 0.366, p = .019) for the most symptomatic leg and between changes in 6MWT and QMVC (r = 0.320, p = .04) and LEP (r = 0.381, p = .01), respectively, for the least symptomatic leg.Conclusions: Resistance training appeared effective for improving muscle mass, but less effective for improving muscle strength, power, and functional performance. Only exercise-induced changes in muscle strength and power of the least symptomatic leg, not the most symptomatic leg, were related to changes in functional performance.

The effect of daily protein supplementation, with or without resistance training for 1 year, on muscle size, strength, and function in healthy older adults: A randomized controlled trial

BACKGROUND

Protein supplementation alone or combined with resistance training has been proposed to be effective in counteracting age-related losses of muscle mass and strength.

OBJECTIVES

To investigate the effect of protein supplementation alone or combined with light-intensity or heavy-load resistance exercise on muscle size, strength, and function in older adults.

METHODS

In a 1-y randomized controlled trial, 208 healthy older adults (>65 y) were randomly assigned to 1 of 5 interventions: 1) carbohydrate supplementation (CARB); 2) collagen protein supplementation (COLL); 3) whey protein supplementation (WHEY); 4) light-intensity resistance training 3-5 times/wk with whey protein supplementation (LITW); and 5) heavy resistance training 3 times weekly with whey protein supplementation (HRTW). Protein supplements contained 20 g protein + 10 g carbohydrate, whereas CARB contained 30 g of carbohydrates. All intervention groups received the supplement twice daily. The primary outcome was change in the quadriceps cross-sectional area (qCSA). Secondary outcomes included measures of lower extremity strength and power, functional capabilities, and body composition.

RESULTS

There were 184 participants who completed the study. COLL and WHEY did not affect any measured parameter compared to CARB. Compared to WHEY, HRTW improved the qCSA size (between-group difference, +1.68 cm2; 95% CI, +0.41 to +2.95 cm2; P = 0.03), as well as dynamic (+18.4 Nm; 95% CI, +10.1 to +26.6 Nm; P < 10-4) and isometric knee extensor strength (+23.9 Nm; 95% CI, +14.2 to +33.6 Nm; P < 10-5). LITW did not improve the qCSA size, but increased dynamic knee extensor strength compared to WHEY (+13.7 Nm; 95% CI, +5.3 and +22.1 Nm; P = 0.01).

CONCLUSIONS

Recommending protein supplementation as a stand-alone intervention for healthy older individuals seems ineffective in improving muscle mass and strength. Only HRTW was effective in both preserving muscle mass and increasing strength. Thus, we recommend that future studies investigate strategies to increase long-term compliance to heavy resistance exercise in healthy older adults. This trial was registered at clinicaltrials.gov as NCT02034760.

Effects of Resistance Training on Muscle Size and Strength in Very Elderly Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Effects of resistance training on muscle strength and hypertrophy are well established in adults and younger elderly. However, less is currently known about these effects in the very elderly (i.e., 75 years of age and older).

OBJECTIVE

To examine the effects of resistance training on muscle size and strength in very elderly individuals.

METHODS

Randomized controlled studies that explored the effects of resistance training in very elderly on muscle strength, handgrip strength, whole-muscle hypertrophy, and/or muscle fiber hypertrophy were included in the review. Meta-analyses of effect sizes (ESs) were used to analyze the data.

RESULTS

Twenty-two studies were included in the review. The meta-analysis found a significant effect of resistance training on muscle strength in the very elderly [difference in ES = 0.97; 95% confidence interval (CI) 0.50, 1.44; p = 0.001]. In a subgroup analysis that included only the oldest-old participants (80 + years of age), there was a significant effect of resistance training on muscle strength (difference in ES = 1.28; 95% CI 0.28, 2.29; p = 0.020). For handgrip strength, we found no significant difference between resistance training and control groups (difference in ES = 0.26; 95% CI - 0.02, 0.54; p = 0.064). For whole-muscle hypertrophy, there was a significant effect of resistance training in the very elderly (difference in ES = 0 30; 95% CI 0.10, 0.50; p = 0.013). We found no significant difference in muscle fiber hypertrophy between resistance training and control groups (difference in ES = 0.33; 95% CI - 0.67, 1.33; p = 0.266). There were minimal reports of adverse events associated with the training programs in the included studies.

CONCLUSIONS

We found that very elderly can increase muscle strength and muscle size by participating in resistance training programs. Resistance training was found to be an effective way to improve muscle strength even among the oldest-old.

Effects of a Long Chain n-3 Polyunsaturated Fatty Acid-rich Multi-ingredient Nutrition Supplement on Body Composition and Physical Function in Older Adults with Low Skeletal Muscle Mass

Six months of supplementation with a multi-ingredient nutrition supplement was investigated in older adults with low skeletal muscle mass given the recently purported benefits of such approaches. Community-dwelling older adults (age, 74.9 ± 3.6 y; M/F, 18/19) participated in a double-blind, placebo-controlled, randomized trial involving daily consumption of either fruit juice placebo (PLA) or supplement (SUPP) in the form of a 200-mL carton of a juice-based emulsion of long chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) (3000 mg as 1500 mg docosahexaenoic acid and 1500 mg eicosapentaenoic acid), whey protein isolate (8 g), vitamin D3 (400 IU), and resveratrol (150 mg). Body composition, physical function, and circulating markers of metabolic health were assessed at baseline (PRE), and after 3 (MID) and 6 (POST) months of supplementation. Lean body mass (LBM) was unchanged in either group, but fat mass increased in SUPP by 1.41 (0.75, 2.07) kg at POST (+6.4%; p < .001; d = 0.20). Hand-grip strength was maintained in SUPP, but declined in PLA by 2.50 (0.81, 4.19) kg at POST (-6.8%; p = .002; d = 0.38). Short physical performance battery score was unchanged in PLA, but increased in SUPP by 1.13 (0.41, 1.84) above PRE at POST (p = .001; d = 0.47). Circulating markers of metabolic health were unchanged in response to the intervention in either PLA or SUPP. Long-term supplementation with an LC n-3 PUFA-rich multi-ingredient nutrition supplement demonstrates potential efficacy for improving physical function in older adults in the absence of exercise training and independent of a change in LBM.

Comparison of Muscle Density in Middle-Aged and Older Chinese Adults Between a High-Altitude Area (Kunming) and a Low-Altitude Area (Beijing)

BACKGROUND AND PURPOSE

A high-altitude environment was known to have a negative effect on bone and lead to a higher incidence of hip fracture. However, the dependence of muscle composition on altitude is unclear. Thus, we aimed to compare muscle density and area in plateau and low altitude area and to determine the effect of the altitude on these outcomes.

METHODS

Community dwelling adults over 60 years old living in Beijing (elevation 50 m; 300 subjects,107 men and 193 women) or Kunming (elevation 2000 m; 218 subjects,83 men and 135 women) for more than 10 years were enrolled. Quantitative CT was performed in all subjects and cross-sectional area and attenuation measured in Hounsfield units (HU) were determined for the trunk, gluteus, and mid-thigh muscles.

RESULTS

Compared to Beijing, Kunming adults were slimmer (Beijing men vs Kunming men: 25.08 ± 2.62 vs 23.94 ± 3.10kg/m², P=0.013; Beijing women vs Kunming women: 25.31 ± 3.1 vs 23.98 ± 3.54 kg/m², P= 0.001) and had higher muscle density in the L2-trunk and gluteus maximus muscles after adjustment for age and BMI (L2-trunk muscles: Beijing men 29.99 ± 4.17 HU vs Kunming men 37.35 ± 4.25 HU, P< 0.0001; Beijing women 27.37 ± 3.76 HU vs Kunming women 31.51 ± 5.12 HU, P< 0.0001; Gluteus maximus muscle: Beijing men 35.11 ± 6.54 HU vs Kunming men 39.36 ± 4.39 HU, P= 0.0009; Beijing women 31.47 ± 6.26 HU vs Kunming women 34.20 ± 5.87 HU P=0.0375). Age was similar in both cohorts and no differences were observed in the gluteus medius and minimus muscle or the mid-thigh muscle, either in the area or density.

CONCLUSIONS

Compared with Beijing, the adults in Kunming had higher muscle density of the gluteus maximus and L2 trunk muscles, showing that living at a higher altitude might be beneficial to muscle quality.

Non-Pharmacological Interventions in Osteosarcopenia: A Systematic Review

BACKGROUND

Osteosarcopenia is a geriatric syndrome defined by the concomitant presence of osteopenia/osteoporosis (loss of bone mineral density (BMD)) and sarcopenia (loss of muscle mass and/or function), which increases the risk of falls, fractures, and premature mortality.

OBJECTIVE

To examine the efficacy of non-pharmacological (exercise and/or nutritional) interventions on musculoskeletal measures and outcomes in osteosarcopenic adults by reviewing findings from randomized controlled trials (RCTs).

METHODS

This review was registered at PROSPERO (registration number: CRD42020179292) and conducted in accordance with the PRISMA guidelines. Electronic databases were searched for RCTs assessing the effect of at least one non-pharmacological intervention (any form of exercise and/or supplementation with protein, vitamin D, calcium or creatine) on any musculoskeletal measure/outcome of interest (BMD, bone strength/turnover, muscle mass and strength, physical performance, falls/fractures) in adults with osteosarcopenia as defined by any proposed criteria.

RESULTS

Two RCTs (of n=106 older osteosarcopenic adults (≥65 years)) assessing the effects of progressive resistance training (RT) (via resistance bands or machines; 2-3 times/week; ~60 minutes in duration) were eligible for inclusion. The two RCTs demonstrated moderate quality evidence that RT increases muscle mass, strength, and quality, with changes in strength and quality occurring before muscle mass (12 vs 28 weeks). There was low quality evidence that RT increases lumbar spine BMD and maintains total hip BMD when performed for 12 and 18 months, respectively, and moderate quality evidence that RT has no effect on markers of bone turnover or physical performance. No major adverse effects were recorded in either of the RCTs. There were no eligible RCTs examining the impact of nutritional interventions.

CONCLUSION

Chronic RT is safe and effective at potentiating gains in muscle mass, strength, and quality, and increasing or maintaining BMD in older osteosarcopenic adults. No RCT has examined the effects of protein, vitamin D, calcium, or creatine against a control/placebo in this high-risk population.

Repair and remodeling of partial-weightbearing, uninstrumented long bone fracture model in mice treated with low intensity vibration therapy

BACKGROUND

While vibration therapy has shown encouraging results across many fields of medicine in the last decade, its role as originally envisioned for bone health remains uncertain. Especially regarding its efficacy in promoting fracture healing, mixed and incomplete outcomes suggest a need to clarify its potential. In particular, the definitive effect of vibration, when isolated from the confounding mechanical inputs of gait and stabilizing instrumentation, remains largely unknown.

METHODS

Four cohorts of C57BL/6 male mice underwent single-leg, open fibula fracture. Vibration was applied at 0.3 g to two groups for 20 min/d. At 3 and 6 weeks, fibulae were harvested for microcomputed tomography and 3-point bending to failure.

FINDINGS

In bone volume and tissue volume, the groups at each healing time point were statistically not different. At 3 weeks, however, the ratio of bone-to-tissue volume was lower for the vibrated group than control. Likewise, while bone mineral density did not differ, tissue volume density was lowest with vibration. At 6 weeks, mean differences were nominal. Biomechanically, vibration consistently trended ahead of control in strength and stiffness, but did not achieve statistical significance.

INTERPRETATION

At this stage of therapeutic development, vibration therapy in isolation does not demonstrate a clear efficacy for bone healing, although further treatment permutations and translational uses remain open for investigation.

Effects of a dynamic combined training on impulse response for middle-aged and elderly patients with osteoporosis and knee osteoarthritis: a randomized control trial

Dynamic combined training is a crucial component in treating musculoskeletal conditions to increase muscle strength and improve functional ability. This randomized control trial aimed to examine the effect of dynamic combined training on muscle strength and contractile rate of force development (RFD) in patients with osteoporosis (OP) and knee osteoarthritis (KOA). 58 participants with OP or KOA were randomly assigned to a control group (CG) (CGOP, n = 12; CGKOA, n = 15) or training group (TG) (TGOP, n = 14; TGKOA, n = 17). The training group participated in a 12-week, three-days-per-week supervised program consisting of stretching and warm-up exercises (10 min), hydraulic resistance training (40 min), and cool-down and relaxation exercises (10 min). All participants were evaluated at baseline and post-training. The maximal voluntary contraction (MVC) and contractile RFD at 0-200 ms increased significantly in middle-aged and older patients with OP. As for KOA, the dynamic combined training program was effective in improving the muscle strength. The maximal voluntary contraction (MVC) and contractile RFD at 0-200 ms increased significantly (by 29.22%, P = .000 and 27.25%, P = .019, respectively) in middle-aged and older patients with OP. In the KOA group, MVC and contractile RFD improved but did not reach statistical significance. The dynamic combined training program is effective for health promotion in older adults with OP or KOA.

Effects of Muscle Strength Training on Muscle Mass Gain and Hypertrophy in Older Adults With Osteoarthritis: A Systematic Review and Meta-Analysis

OBJECTIVE

To investigate the effect of muscle strength exercise training (MSET) on lean mass (LM) gain and muscle hypertrophy in older patients with lower extremity osteoarthritis (OA).

METHODS

A comprehensive search of online databases was performed on April 20, 2019. Randomized controlled trials (RCTs) that reported the effects of MSET on LM, muscle thickness, and cross-sectional area (CSA) in older patients with OA were identified. A risk of bias assessment and meta-analysis were performed for the included RCTs.

RESULTS

We included 19 RCTs with a median Physiotherapy Evidence Database score of 6 of 10 (range 3-7). In total, data from 1,195 patients (65% women, 85% with knee OA) with a mean age of 62.1 years (range 40-86 years) were analyzed. MSET resulted in significantly higher LM gain (standardized mean difference [SMD] 0.49 [95% confidence interval (95% CI) 0.28, 0.71], P < 0.00001) than did the nonexercise controls. Meta-analysis results revealed significantly positive effects of MSET on muscle thickness (SMD 0.82 [95% CI 0.20, 1.43], P = 0.009) and CSA (SMD 0.80 [95% CI 0.25, 1.35], P = 0.004) compared with nonexercise controls. No significant effects in favor of MSET were observed for any muscle outcome compared with exercise controls. Five RCTs reported nonsevere adverse events in response to MSET, whereas no RCTs reported severe events.

CONCLUSION

MSET is effective in increasing LM and muscle size in older adults with OA. Clinicians should incorporate MSET into their management of patients at risk of low muscle mass to maximize health status, particularly for older individuals with OA.

Sarcopenia during COVID-19 lockdown restrictions: long-term health effects of short-term muscle loss

The COVID-19 pandemic is an extraordinary global emergency that has led to the implementation of unprecedented measures in order to stem the spread of the infection. Internationally, governments are enforcing measures such as travel bans, quarantine, isolation, and social distancing leading to an extended period of time at home. This has resulted in reductions in physical activity and changes in dietary intakes that have the potential to accelerate sarcopenia, a deterioration of muscle mass and function (more likely in older populations), as well as increases in body fat. These changes in body composition are associated with a number of chronic, lifestyle diseases including cardiovascular disease (CVD), diabetes, osteoporosis, frailty, cognitive decline, and depression. Furthermore, CVD, diabetes, and elevated body fat are associated with greater risk of COVID-19 infection and more severe symptomology, underscoring the importance of avoiding the development of such morbidities. Here we review mechanisms of sarcopenia and their relation to the current data on the effects of COVID-19 confinement on physical activity, dietary habits, sleep, and stress as well as extended bed rest due to COVID-19 hospitalization. The potential of these factors to lead to an increased likelihood of muscle loss and chronic disease will be discussed. By offering a number of home-based strategies including resistance exercise, higher protein intakes and supplementation, we can potentially guide public health authorities to avoid a lifestyle disease and rehabilitation crisis post-COVID-19. Such strategies may also serve as useful preventative measures for reducing the likelihood of sarcopenia in general and in the event of future periods of isolation.

Resistance Exercise, Electrical Muscle Stimulation, and Whole-Body Vibration in Older Adults: Systematic Review and Meta-Analysis of Randomized Controlled Trials

It has been shown that resistance exercise (RT) is one of the most effective approaches to counteract the physical and functional changes associated with aging. This systematic review with meta-analysis compared the effects of RT, whole-body vibration (WBV), and electrical muscle stimulation (EMS) on muscle strength, body composition, and functional performance in older adults. A thorough literature review was conducted, and the analyses were limited to randomized controlled trials. In total, 63 studies were included in the meta-analysis (48 RT, 11 WBV, and 4 EMS). The results showed that RT and WBV are comparably effective for improving muscle strength, while the effects of EMS remains debated. RT interventions also improved some outcome measures related to functional performance, as well as the cross-sectional area of the quadriceps. Muscle mass was not significantly affected by RT. A limitation of the review is the smaller number of WBV and particularly EMS studies. For this reason, the effects of WBV and EMS could not be comprehensively compared to the effect of RT for all outcome measures. For the moment, RT or combinations of RT and WBV or EMS, is probably the most reliable way to improve muscle strength and functional performance, while the best approach to increase muscle mass in older adults remains open to further studies.

Effects of High-Intensity Resistance Training on Osteopenia and Sarcopenia Parameters in Older Men with Osteosarcopenia-One-Year Results of the Randomized Controlled Franconian Osteopenia and Sarcopenia Trial (FrOST)

Dynamic resistance exercise (DRT) might be the most promising agent for fighting sarcopenia in older people. However, the positive effect of DRT on osteopenia/osteoporosis in men has still to be confirmed. To evaluate the effect of low-volume/high-intensity (HIT)-DRT on bone mineral density (BMD) and skeletal muscle mass index (SMI) in men with osteosarcopenia, we initiated the Franconian Osteopenia and Sarcopenia Trial (FrOST). Forty-three sedentary community-dwelling older men (aged 73 to 91 years) with osteopenia/osteoporosis and SMI-based sarcopenia were randomly assigned to a HIT-RT exercise group (EG; n = 21) or a control group (CG; n = 22). HIT-RT provided a progressive, periodized single-set DRT on machines with high intensity, effort, and velocity twice a week, while CG maintained their lifestyle. Both groups were adequately supplemented with whey protein, vitamin D, and calcium. Primary study endpoint was integral lumbar spine (LS) BMD as determined by quantitative computed tomography. Core secondary study endpoint was SMI as determined by dual-energy X-ray absorptiometry. Additional study endpoints were BMD at the total hip and maximum isokinetic hip-/leg-extensor strength (leg press). After 12 months of exercise, LS-BMD was maintained in the EG and decreased significantly in the CG, resulting in significant between-group differences (p < 0.001; standardized mean difference [SMD] = 0.90). In parallel, SMI increased significantly in the EG and decreased significantly in the CG (p < 0.001; SMD = 1.95). Total hip BMD changes did not differ significantly between the groups (p = 0.064; SMD = 0.65), whereas changes in maximum hip-/leg-extensor strength were much more prominent (p < 0.001; SMD = 1.92) in the EG. Considering dropout (n = 2), attendance rate (95%), and unintended side effects/injuries (n = 0), we believe our HIT-RT protocol to be feasible, attractive, and safe. In summary, we conclude that our combined low-threshold HIT-RT/protein/vitamin D/calcium intervention was feasible, safe, and effective for tackling sarcopenia and osteopenia/osteoporosis in older men with osteosarcopenia. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.

Age-dependent stress response DNA demethylation and gene upregulation accompany nuclear and skeletal muscle remodeling following acute resistance-type exercise in rats

Efficacy of high-intensity resistance exercise becomes progressively compromised with aging. Previously, to investigate this, we developed a rodent model of high-intensity training consisting of stretch-shortening contractions (SSCs) and determined that following one month of training, young rats exhibit a robust stress response and 20% performance increase, whereas old rats display a muted stress response and 30% performance decrease. Whether these age-specific responses occur early in training and constitute primary factors in adaptation/maladaptation was not addressed. The aim of the present study was to characterize performance, remodeling, and stress response transcriptional profile 6–120 h following acute SSC exposure. For young rats, the stress response pathway was highly regulated (≥20 differentially expressed genes at each time point) and was accompanied by robust DNA demethylation, tissue remodeling, and isometric torque recovery. For old rats, a muted transcriptional profile (13 and 2 differentially expressed genes at 6 and 120 h, respectively) coincided with deficiencies in demethylation, muscle remodeling, and torque recovery. These findings occurred in the context of heightened chronic levels of stress response gene expression with aging. This demonstrates that age-related constitutive elevations in stress response gene expression was accompanied by diminished SSC-induced responsiveness in epigenomic regulation and tissue remodeling.

The effect of vitamin D on sarcopenia depends on the level of physical activity in older adults

OBJECTIVE

Sarcopenia in older adults is closely related to vitamin D deficiency and reduced levels of physical activity, but little has been reported on the interaction between physical activity and the positive effects of vitamin D. The purpose of this study was to explore the interactive effect of vitamin D and physical activity on muscle mass and function through animal experiments and population surveys.

METHODS

Male 4-week-old C57BL/6J mice were fed different purified diets: a vitamin D-deficient diet (with increased calcium and phosphorus to prevent the effects of abnormal mineral levels on muscle) or a 1,25-dihydroxyvitamin D3 (1,25D)-supplemented diet. After 24 weeks on the assigned diets, the mice were immobilized. The level of skeletal muscle atrophy in the mice was determined by grip strength, gastrocnemius (GA) muscle mass and muscle fiber cross-sectional area (CSA); additionally, the protein expression levels of FOXO3a and the E3 ubiquitin ligases MuRF1 and MAFbx were detected. A cross-sectional study included data from 4139 older adults (64.9% women, 67.9 ± 6.7 years) as part of a survey in Shenyang, Northeast China. The associations of serum 25(OH)D3 and physical activity with timed up and go test (TUG) performance, handgrip strength, calf circumference, and body muscle mass were assessed by a linear regression analysis that was adjusted for covariates.

RESULTS

In activity-limited mice, vitamin D deficiency accelerated the decrease in GA muscle weight, muscle fiber CSA, and grip strength and increased the protein expression of MuRF1, MAFbx, and FOXO3a (all P < 0.05). In addition, 1,25D supplementation may inhibit the grip-strength reduction induced by limited activity (P = 0.069). Serum 25(OH)D3 and physical activity were linearly related to TUG time (P < 0.001) and handgrip strength (P < 0.05) after adjustment for sex, age, body mass index (BMI), education level, smoking status, and serum calcium level. Serum 25(OH)D3 and physical activity had interactive effects on TUG (P < 0.001) and handgrip strength (P < 0.05) but not calf circumference or body muscle mass in older adults.

CONCLUSIONS

The effect of vitamin D on muscle strength and physical performance depends on physical activity level in the elderly. It is recommended that older adults strive to avoid both physical inactivity and vitamin D deficiency. Because physical inactivity and vitamin D deficiency may exacerbate muscle atrophy, the biological mechanism may involve synergistic effects of vitamin D and physical activity on the promotion of muscle protein ubiquitination and degradation.

Strength training and protein supplementation improve muscle mass, strength, and function in mobility-limited older adults: a randomized controlled trial

BACKGROUND

Adaptation to strength training in very old mobility-limited individuals is not fully characterized. Therefore, the aim of this study was to perform a thorough investigation of the adaptation to a lower body strength training regime in this population, with particular emphasis on the relationship between changes in selected variables.

METHODS

Twenty-two mobility-limited older men and women (85 ± 6 years) were randomized to either a group performing 30 min of heavy-load strength training three times a week, with daily protein supplementation, for 10 weeks (ST), or a control group. End points were leg lean mass assessed by DXA, muscle thickness assessed by ultrasound, isometric and dynamic strength, rate of torque development, and functional capacity.

RESULTS

Leg lean mass increased from baseline in ST (0.7 ± 0.3 kg), along with increased thickness of vastus lateralis (4.4 ± 3.2%), rectus femoris (6.7 ± 5.1%), and vastus intermedius (5.8 ± 5.9%). The hypertrophy was accompanied by improved knee extensor strength (20-23%) and functional performance (7-11%). In ST, neither the change in leg lean mass nor muscle thickness correlated with changes in muscle strength. However, a strong correlation was observed between the change in isometric strength and gait velocity (r = 0.70).

CONCLUSIONS

The mismatch between gains in muscle size and strength suggests that muscle quality-related adaptations contributed to the increases in strength. The correlations observed between improvements in strength and function suggests that interventions eliciting large improvements in strength may also be superior in terms of functional gains in this population.

High Intensity Resistance Exercise Training to Improve Body Composition and Strength in Older Men With Osteosarcopenia. Results of the Randomized Controlled Franconian Osteopenia and Sarcopenia Trial (FrOST)

Considerably decreased muscle mass and function are subsumed under "sarcopenia," a geriatric syndrome. Dedicated exercise programs maintain muscle mass and function; however, due to the limited enthusiasm of older adults to exercise, it is important to generate low-threshold interventions for this vulnerable cohort. Thus, the primary aim of this study was to determine the effect of low volume/high intensity resistance exercise training (HIT-RT) combined with protein supplementation on body composition and strength in older men with sarcopenia and osteopenia (osteosarcopenia). Forty-three community-dwelling (cdw) older men (78 ± 4 years) with osteosarcopenia were randomly allocated to a consistently supervised HIT-RT (n = 21) or an inactive control group (CG, n = 22). HIT-RT scheduled a single set protocol with high intensity and effort applied twice a week for 36 weeks so far. Both groups were supplemented with Vit-D (800 IE/d), calcium (1,000 mg/d) and whey-protein (CG: 1.2 vs. HIT-RT: 1.5-1.7 g/kg/d). Study endpoints were body composition (dual-energy x-ray absorptiometry) and maximum isokinetic hip/leg-extensor strength (MIES) by leg-press. After 36 weeks, one participant who developed prostate cancer after inclusion in the study (HIT-RT) and two participants who lost interest (CG, HIT-RT) quit the study. Attendance rate for HIT-RT averaged 93 ± 5%. Total and thigh lean body mass (LBM) significantly (p < 0.001) increased in the HIT-RT and was maintained in the CG (p = 0.46 and 0.37). Differences between the groups for changes of total and thigh LBM were pronounced (p < 0.001; SMD d' = 1.17 and 1.20). Total and abdominal body fat percentage decreased significantly in the HIT-RT (p < 0.001) and increased in the CG (p = 0.039 and p = 0.097). Intergroup differences were significant (p < 0.001; SMD: d' = 1.35 and 1.28). Finally, MIES was maintained in the CG (p = 0.860), and improved significantly (p < 0.001) in the HIT-RT. Differences between the groups were significant (p < 0.001, SMD: d' = 2.41). No adverse effects of the intervention were observed. In summary, the HIT-RT/protein protocol significantly affected body composition and strength in cdw men 72 years+ with osteosarcopenia. In the absence of negative side effects, the intervention was feasible, attractive and time effective. Thus, we conclude that supervised HIT-RT might be an exercise option for older men.

A randomized controlled trial of the effect of supervised progressive cross-continuum strength training and protein supplementation in older medical patients: the STAND-Cph trial

Background

During hospitalization, older adults (+ 65 years) are inactive, which puts them at risk of functional decline and loss of independence. Systematic strength training can prevent loss of functional performance and combining strength training with protein supplementation may enhance the response in muscle mass and strength. However, we lack knowledge about the effect of strength training commenced during hospitalization and continued after discharge in older medical patients. This assessor-blinded, randomized study investigated the effect of a simple, supervised strength training program for the lower extremities, combined with post-training protein supplementation during hospitalization and in the home setting for 4 weeks after discharge, on the effect on change in mobility in older medical patients.

Methods

Older medical patients (≥ 65 years) admitted acutely from their home to the Emergency Department were randomized to either standard care or supervised progressive strength training and an oral protein supplement during hospitalization and at home 3 days/week for 4 weeks after discharge. The primary outcome was between-group difference in change in mobility from baseline to 4 weeks after discharge assessed by the De Morton Mobility Index, which assesses bed mobility, chair mobility, static and dynamic balance, and walking. Secondary outcomes were 24-h mobility, lower extremity strength, gait speed, grip strength and activities of daily living.

Results

Eighty-five patients were randomized to an intervention group (N = 43) or a control group (N = 42). In the intervention group, 43% were highly compliant with the intervention. Our intention-to-treat analysis revealed no between-group difference in mobility (mean difference in change from baseline to 4 weeks, − 4.17 (95% CI − 11.09; 2.74; p = 0.24) nor in any of the secondary outcomes. The per-protocol analysis showed that the daily number of steps taken increased significantly more in the intervention group compared to the control group (mean difference in change from baseline to 4 weeks, 1033.4 steps (95% CI 4.1; 2062.7), p = 0.049, adjusted for mobility at baseline and length of stay; 1032.8 steps (95% CI 3.6; 2061.9), p = 0.049, adjusted for mobility at baseline, length of stay, and steps at baseline).

Conclusions

Simple supervised strength training for the lower extremities, combined with protein supplementation initiated during hospitalization and continued at home for 4 weeks after discharge was not superior to usual care in the effect on change in mobility at 4 weeks in older medical patients. For the secondary outcome, daily number of steps, high compliance with the intervention resulted in a greater daily number of steps. Less than half of the patients were compliant with the intervention indicating that a simpler intervention might be needed.

Trial registration

ClinicalTrials.gov, NCT01964482. Registered on 14 October 2013. Trial protocol PubMed ID (PMID), 27039381.

[Sarcopenia and frailty in older patients with rheumatism]

Sarcopenia is an age-related generalized loss of muscle mass and muscle strength resulting in low physical performance, which can be observed in up to 50% of >80-year-old individuals. The consequences are manifold and sarcopenia is closely linked to frailty. Important risk factors are genetics/epigenetics, immobilization, malnutrition and anorexia, hormone deficiencies, chronic inflammation and raised levels of inhibitory factors of tissue regeneration. Thus, functional assessment of muscle strength and physical performance are central components of diagnosing sarcopenia, beyond the mere quantification of muscle mass. Currently, many interventional strategies are being tested, including exercise regimens, nutrition programs, hormone replacement and pharmacological strategies involving anabolic principles. According to the current data, training programs and medications have a high potential.

Lipotoxicity plays a key role in the development of both insulin resistance and muscle atrophy in patients with type 2 diabetes

Insulin resistance and muscle mass loss often coincide in individuals with type 2 diabetes. Most patients with type 2 diabetes are overweight, and it is well established that obesity and derangements in lipid metabolism play an important role in the development of insulin resistance in these individuals. Specifically, increased adipose tissue mass and dysfunctional adipose tissue lead to systemic lipid overflow and to low-grade inflammation via altered secretion of adipokines and cytokines. Furthermore, an increased flux of fatty acids from the adipose tissue may contribute to increased fat storage in the liver and in skeletal muscle, resulting in an altered secretion of hepatokines, mitochondrial dysfunction, and impaired insulin signalling in skeletal muscle. Recent studies suggest that obesity and lipid derangements in adipose tissue can also lead to the development of muscle atrophy, which would make insulin resistance and muscle atrophy two sides of the same coin. Unfortunately, the exact relationship between lipid accumulation, type 2 diabetes, and muscle atrophy remains largely unexplored. The aim of this review is to discuss the relationship between type 2 diabetes and muscle loss and to discuss some of the joint pathways through which lipid accumulation in organs may affect peripheral insulin sensitivity and muscle mass.

Supervised Physical Training Enhances Muscle Strength but Not Muscle Mass in Prostate Cancer Patients Undergoing Androgen Deprivation Therapy: A Systematic Review and Meta-Analysis

Introduction: Androgen deprivation therapy (ADT) is considered the basic treatment for advanced prostate cancer, but it is highly associated with detrimental changes in muscle mass and muscle strength. The aim of this meta-analysis was to investigate the effects of supervised physical training on lean mass and muscle strength in prostate cancer patients undergoing ADT.

Methods: A systematic literature search was performed using MEDLINE, Embase, and ScienceDirect until October 2018. Only studies that examined both muscle mass and strength in prostate cancer patients undergoing ADT were included. Outcomes of interest were changes in lean body mass (surrogate for muscle mass) as well as upper and lower body muscle strength. The meta-analysis was performed with fixed-effects models to calculate mean differences between intervention and no-training control groups.

Results: We identified 8,521 publications through the search of the following key words: prostate cancer, prostate tumor, prostate carcinoma, prostate neoplasm, exercise, and training. Out of these studies, seven randomized controlled trials met the inclusion criteria and where included in the analysis. No significant mean differences for changes in lean mass were observed between the intervention and control groups (0.49 kg, 95% CI: −0.76, 1.74; P = 0.44). In contrast, the mean difference for muscle strength was significant both in chest (3.15 kg, 95% CI: 2.46, 3.83; P < 0.001) and in leg press (27.46 kg, 95% CI: 15.05, 39.87; p < 0.001).

Conclusion: This meta-analysis provides evidence that low- to moderate-intensity resistance and aerobic training is effective for increasing muscle strength but may not be sufficient to affect muscle mass in prostate cancer patients undergoing ADT. The underlying mechanisms for this maladaptation may in part be explained by an insufficient stimulus induced by the training regimens as well as a delayed initiation of training in relation to the start of ADT. When interpreting the present findings, one should bear in mind that the overall number of studies included in this review was rather low, emphasizing the need for further studies in this field.

The effect of cognitive function on mobility improvement among community-living older adults: A 12-week resistance exercise intervention study

The purpose of the study was to investigate the association between baseline cognitive function and improvement in mobility after 12 weeks of resistance training (3 times/week; 3 sets, 6-8 repetitions at 75-80% of the 1-repetition maximum) among community-dwelling older adults in Iceland (N=205, 73.5±5.7 years, 57.0% female). Body composition, physical activity status, cardiovascular risk factors, 6-minute walk test (6MWT), and Mini-Mental State Examination (MMSE) were measured. The linear regression model was used to examine the association between baseline MMSE and mobility improvement. Mean distance of 6MWT was 462.8±71.6 meter at baseline and mean change after the exercise intervention was 33.7±34.9 meter. The mean MMSE score at baseline was 27.6±1.9. After adjusting for baseline covariates, we found that baseline MMSE score was significantly associated with improvement in mobility among older adults after the exercise intervention. Cognitive function strongly influences the effect of exercise intervention on mobility among older adults.

Combating osteoporosis and obesity with exercise: leveraging cell mechanosensitivity

Osteoporosis, a condition of skeletal decline that undermines quality of life, is treated with pharmacological interventions that are associated with poor adherence and adverse effects. Complicating efforts to improve clinical outcomes, the incidence of obesity is increasing, predisposing the population to a range of musculoskeletal complications and metabolic disorders. Pharmacological management of obesity has yet to deliver notable reductions in weight and debilitating complications are rarely avoided. By contrast, exercise shows promise as a non-invasive and non-pharmacological method of regulating both osteoporosis and obesity. The principal components of exercise - mechanical signals - promote bone and muscle anabolism while limiting formation and expansion of fat mass. Mechanical regulation of bone and marrow fat might be achieved by regulating functions of differentiated cells in the skeletal tissue while biasing lineage selection of their common progenitors - mesenchymal stem cells. An inverse relationship between adipocyte versus osteoblast fate selection from stem cells is implicated in clinical conditions such as childhood obesity and increased marrow adiposity in type 2 diabetes mellitus, as well as contributing to skeletal frailty. Understanding how exercise-induced mechanical signals can be used to improve bone quality while decreasing fat mass and metabolic dysfunction should lead to new strategies to treat chronic diseases such as osteoporosis and obesity.

Physical Activity and Sports-Real Health Benefits: A Review with Insight into the Public Health of Sweden

Positive effects from sports are achieved primarily through physical activity, but secondary effects bring health benefits such as psychosocial and personal development and less alcohol consumption. Negative effects, such as the risk of failure, injuries, eating disorders, and burnout, are also apparent. Because physical activity is increasingly conducted in an organized manner, sport’s role in society has become increasingly important over the years, not only for the individual but also for public health. In this paper, we intend to describe sport’s physiological and psychosocial health benefits, stemming both from physical activity and from sport participation per se. This narrative review summarizes research and presents health-related data from Swedish authorities. It is discussed that our daily lives are becoming less physically active, while organized exercise and training increases. Average energy intake is increasing, creating an energy surplus, and thus, we are seeing an increasing number of people who are overweight, which is a strong contributor to health problems. Physical activity and exercise have significant positive effects in preventing or alleviating mental illness, including depressive symptoms and anxiety- or stress-related disease. In conclusion, sports can be evolving, if personal capacities, social situation, and biological and psychological maturation are taken into account. Evidence suggests a dose–response relationship such that being active, even to a modest level, is superior to being inactive or sedentary. Recommendations for healthy sports are summarized.

Whole-body vibration for patients with nonalcoholic fatty liver disease: a 6-month prospective study

Physical exercise has demonstrated benefits for managing nonalcoholic fatty liver disease (NAFLD). However, in daily life maintaining exercise without help may be difficult. A whole-body vibration device (WBV) has been recently introduced as an exercise modality that may be suitable for patients who have difficulty engaging in exercise. We tested WBV in patients with NAFLD and estimated its effectiveness. We studied the effects of a 6-month WBV program on hepatic steatosis and its underlying pathophysiology in 25 patients with NAFLD. Seventeen patients with NAFLD were designated as a control group. After WBV exercise, body weight in the study group decreased by only 2.5% compared with the control group. However, we found significant increases in muscle area (+2.6%) and strength (+20.5%) and decreases in fat mass (-6.8%). The hepatic (-9.9%) and visceral (-6.2%) fat content also significantly decreased (P < 0.05). There was substantial lowering of hepatic stiffness (-15.7%), along with improvements in the levels of inflammatory markers; tumor necrosis factor alpha (-50.9%), adiponectin (+12.0%), ferritin (-33.2%), and high-sensitivity C-reactive protein (-43.0%) (P < 0.05). These results suggest that WBV is an exercise option for patients with NAFLD that is effective, efficient, and convenient.

Different strength declines in leg primary movers versus stabilizers across age-Implications for the risk of falls in older adults?

This study investigated differences in the declines of isometric strength in hip abductors and adductors versus knee extensors across four different age groups (n = 31: 11.2 ± 1.0 y, n = 30: 23.1 ± 2.7 y, n = 27: 48.9 ± 4.4 y, and n = 33: 70.1 ± 4.2 y) with a total of 121 female subjects. As a starting point, we assumed that, during their daily activities, elderly people would use their leg stabilizers less frequently than their leg primary movers as compared to younger people. Given that muscle strength decreases in the course of the aging process, we hypothesized that larger strength declines in hip abductors and hip adductors as compared to knee extensors would be detected across age. Maximal isometric force for these muscle groups was assessed with a digital hand-held dynamometer. Measurements were taken at 75% of the thigh or shank length and expressed relative to body weight and lever arm length. Intratester reliability of the normalized maximal torques was estimated by using Cronbach’s alpha and calculated to be larger than 0.95. The obtained results indicate a clearly more pronounced strength decline in hip abductors and hip adductors across age than in the knee extensors. Therefore, a particular need for strength training of the lower extremity stabilizer muscles during the aging process is implied.

Effects of short-term resistance training on endothelial function and inflammation markers in elderly patients with type 2 diabetes: A randomized controlled trial

PURPOSE

To evaluate the effects of 12-weeks of strength training on endothelial function and inflammatory markers in elderly individuals with T2DM.

METHODS

Forty-four elderly patients with T2DM were screened for participation. After completion of the baseline assessment, participants were randomly assigned to either the resistance training group (RT) or an active control group (AC). Inflammatory (TNF-α, IL-6, IL-1β, IL-10 and CRP) and blood lipid profiles, glycated hemoglobin, basal artery diameter and flow mediated dilation were evaluated before and after the intervention. Comparisons between groups were obtained from the generalized estimation equation and all tests were two-tailed and the alpha level for significance set at 0.05.

RESULTS

TNF-α and IL-1β were decreased in both groups, while no interactions were found for flow mediated dilation and basal artery diameter. No significant differences were found for blood lipid profile and glycated hemoglobin for both groups after the intervention period.

CONCLUSIONS

No significant changes were found between the RT and AC groups, regarding inflammatory profile and endothelial function, which does not prove the superiority of this intervention model in the studied period.

Effects of Resistance Exercise on Bone Health

The prevalence of chronic diseases including osteoporosis and sarcopenia increases as the population ages. Osteoporosis and sarcopenia are commonly associated with genetics, mechanical factors, and hormonal factors and primarily associated with aging. Many older populations, particularly those with frailty, are likely to have concurrent osteoporosis and sarcopenia, further increasing their risk of disease-related complications. Because bones and muscles are closely interconnected by anatomy, metabolic profile, and chemical components, a diagnosis should be considered for both sarcopenia and osteoporosis, which may be treated with optimal therapeutic interventions eliciting pleiotropic effects on both bones and muscles. Exercise training has been recommended as a promising therapeutic strategy to encounter the loss of bone and muscle mass due to osteosarcopenia. To stimulate the osteogenic effects for bone mass accretion, bone tissues must be exposed to mechanical load exceeding those experienced during daily living activities. Of the several exercise training programs, resistance exercise (RE) is known to be highly beneficial for the preservation of bone and muscle mass. This review summarizes the mechanisms of RE for the preservation of bone and muscle mass and supports the clinical evidences for the use of RE as a therapeutic option in osteosarcopenia.

Are Canadian protein and physical activity guidelines optimal for sarcopenia prevention in older adults?

Aging is characterized by physiological and morphological changes that affect body composition, strength, and function, ultimately leading to sarcopenia. This condition results in physical disability, falls, fractures, poor quality of life, and increased health care costs. Evidence suggests that increased consumption of dietary protein and physical activity levels, especially resistance exercise, can counteract the trajectory of sarcopenia. Canadian guidelines for protein intake and physical activity were last updated in 2005 and 2011, respectively, and new evidence on sarcopenia diagnosis, prevention, and treatment is rapidly evolving. Protein recommendations are set as “one-size-fits-all” for both young and older adults. Recent evidence demonstrates that current recommendations are insufficient to meet the minimum protein requirement to counteract muscle loss and to stimulate hypertrophy in healthy older adults. Beyond quantity, protein quality is also essential to benefit muscle anabolism in older adults. In terms of physical activity, resistance exercise training is a potential strategy to counteract age-related effects, as it can elicit muscle hypertrophic response in addition to increases in muscle strength and function in older adults. Canadian physical activity guidelines lack details on how this modality of training should be performed. Current guidelines for protein intake and physical activity do not reflect recent knowledge on sarcopenia prevention. The gap between guidelines and the latest evidence on the maintenance and promotion of older adult’s health highlight the need for updated protein and physical activity recommendations.

Changes of Maximum Leg Strength Indices During Adulthood a Cross-Sectional Study With Non-athletic Men Aged 19-91

Age-related loss of muscle mass and function, also called sarcopenia, was recently added to the ICD-10 as an independent condition. However, declines in muscle mass and function are inevitable during the adulthood aging process. Concerning muscle strength as a crucial aspect of muscle function, maximum knee extension strength might be the most important physical parameter for independent living in the community. In this study, we aimed to determine the age-related decline in maximum isokinetic knee extension (MIES) and flexion strength (MIFS) in adult men. The primary study hypothesis was that there is a slight gradual decrease of MIES up to ≈age 60 years with a significant acceleration of decline after this "changepoint." We used a closed kinetic chain system (leg-press), which is seen as providing functionally more relevant results on maximum strength, to determine changes in maximum isokinetic hip/leg extensor (MIES) and flexor strength (MIFS) during adulthood in men. Apart from average annual changes, we aimed to identify whether the decline in maximum lower extremity strength is linear. MIES and MIFS data determined by an isokinetic leg-press of 362 non-athletic, healthy, and community-dwelling men 19-91 years old were included in the analysis. A changepoint analysis was conducted based on a multiple regression analysis adjusted for selected co-variables that might confound the proper relationship between age and maximum strength. In summary, maximum isokinetic leg-strength decline during adulthood averaged around 0.8-1.0% p.a.; however, the reduction was far from linear. MIES demonstrated a non-significant reduction of 5.2 N/p.a. (≈0.15% p.a.) up to the estimated breakpoint of 52.0 years and an accelerated loss of 44.0 N/p.a. (≈1.3% p.a.; p < 0.001). In parallel, the decline in MIFS (10.0 N/p.a.; ≈0.5% p.a.) prior to the breakpoint at age 59.0 years was significantly more pronounced. Nevertheless, we observed a further marked accelerated loss of MIFS (25.0 N/p.a.; ≈1.3% p.a.) in men ≥60 years. Apart from the "normative value" and closed kinetic chain aspect of this study, the practical application of our results suggests that sarcopenia prophylaxis in men should be started in the 5th decade in order to address the accelerated muscle decline of advanced age.

Effects of protein supplementation on lean body mass, muscle strength, and physical performance in nonfrail community-dwelling older adults: a systematic review and meta-analysis

Background

Increasing protein intake has been suggested as an effective strategy to ameliorate age-related loss of muscle mass and strength. Current reviews assessing the effect of protein supplementation are strongly influenced by the inclusion of studies with frail older adults.

Objectives

We assessed the effect of protein supplementation on lean body mass, muscle strength, and physical performance in exclusively nonfrail community-dwelling older adults. Moreover, we assessed the superior effects of protein supplementation during concomitant resistance exercise training on muscle characteristics.

Design

A systematic literature search was conducted on PubMed, Embase, and Web of Science up to 15 May 2018. We included randomized controlled trials that assessed the effect of protein supplementation on lean body mass, muscle thigh cross-sectional area, muscle strength, gait speed, and chair-rise ability and performed random-effects meta-analyses.

Results

Data from 36 studies with 1682 participants showed no significant effects of protein supplementation on changes in lean body mass [standardized mean difference (SMD): 0.11; 95% CI: -0.06, 0.28], handgrip strength (SMD: 0.58; 95% CI: -0.08, 1.24), lower extremity muscle strength (SMD: 0.03; 95% CI: -0.20, 0.27), gait speed (SMD: 0.41; 95% CI: -0.04, 0.85), or chair-rise ability (SMD: 0.10; 95%: CI -0.08, 0.28) compared with a control condition in nonfrail community-dwelling older adults. Moreover, no superior effects of protein supplementation were found during concomitant resistance exercise training on muscle characteristics.

Conclusions

Protein supplementation in nonfrail community-dwelling older adults does not lead to increases in lean body mass, muscle cross-sectional area, muscle strength, or physical performance compared with control conditions; nor does it exert superior effects when added to resistance exercise training. Habitual protein intakes of most study participants were already sufficient, and protein interventions differed in terms of type of protein, amount, and timing. Future research should clarify what specific protein supplementation protocol is beneficial for nonfrail community-dwelling older adults with low habitual protein intake.