Sex-specific relationships of physical activity, body composition, and muscle quality with lower-extremity physical function in older men and women

Dynapenia and sarcopenia identify walking speed decline in women but not in men

OBJECTIVE

To determine the best indicator of mobility decline between dynapenia, low skeletal muscle mass index (SMMI), and sarcopenia defined by the EWGSOP2 using different cutoff points for grip strength.

METHODS

A longitudinal study was conducted with a follow-up of eight years, involving 2,680 individuals aged 60 and older who participated in the ELSA study with a walking speed greater than 0.8 m/s at baseline. Dynapenia was defined using different cutoff points for grip strength. SMMI was defined by the 20th percentile of the entire ELSA sample distribution and sarcopenia was defined based on the EWGSOP2, using different cutoff points for grip strength. Mobility was analysed using the walking speed test.

RESULTS

Over time, the greatest decline in walking speed occurred in dynapenic women with grip strength < 17 kg (-0.005 m/s per year; 95 % CI: -0.01 to -0.001) and < 20 kg (-0.007 m/s per year; 95 % CI: -0.01 to -0.001). With regards to sarcopenia, the greatest walking speed decline occurred in women with probable sarcopenia when defined by grip strength < 17 kg [(-0.006 m/s per year; 95 % CI: -0.01 to -0.001) or grip strength < 20 kg (-0.007 m/s per year; 95 % CI: -0.01 to -0.001)]. Dynapenia in men as well as low SMMI and sarcopenia in men and women did not enable identifying the risk of mobility decline.

CONCLUSION

Dynapenia and probable sarcopenia defined by grip strength < 17 kg and < 20 kg enabled identifying walking speed decline over time only in women.

Higher volume resistance training enhances whole-body muscle hypertrophy in postmenopausal and older females: A secondary analysis of systematic review and meta-analysis of randomized clinical trials

OBJECTIVE

This study explored the effects of resistance training (RT) volume on muscle hypertrophy in postmenopausal and older females.

METHODS

This systematic review searched randomized controlled trials (RCTs) on PubMed/MEDLINE, Scopus, Web of Science, and SciELO. Studies with postmenopausal (age ≥ 45 y) or older females (age ≥ 60 y) that compared RT (whole-body) effects on muscle hypertrophy with a control group (CG) were included. Independently reviewers selected the studies, extracted data, and performed the risk of bias of RCTs (RoB2) and certainty of the evidence (GRADE). Whole-body lean mass, free-fat mass, and skeletal muscle mass measurements were included as muscle hypertrophy outcomes. A random-effects model standardized mean difference (Hedges'g), and 95% confidence interval (95%CI) were used for meta-analysis.

RESULTS

Fourteen RCTs (overall RoB2: some concerns, except one study with high risk; GRADE: low evidence) were included. RT groups were divided into low (LVRT, total volume: 445.0 au) and high-volume (HVRT, total volume: 997.3 au). Most exercises performed were arm curl, bench press or chest press, calf raise, leg curl, leg extension, leg press or squat, seated row or lat pulldown, and triceps pushdown. Both groups experienced muscle hypertrophy (HVRT = ∼1.3 kg vs. LVRT = ∼0.9 kg) when compared to CG, although HVRT demonstrated moderate effects size (HVRT = 0.52, 95%CI: 0.27, 0.77) and LVRT demonstrated small effects size (LVRT = 0.34, 95%CI: 0.14, 0.53).

CONCLUSIONS

Compared to CG, results suggest that the HVRT protocol elicits superior improvements in muscle hypertrophy outcomes than LVRT in postmenopausal and older females.

A social media game to increase physical activity among older adult women: protocol of a randomized controlled trial to evaluate CHALLENGE

BACKGROUND

Older adult women often do not engage in sufficient physical activity (PA) and can encounter biological changes that exacerbate the negative effects of inadequate activity. Wearable activity monitors can facilitate PA initiation, but evidence of sustained behavior change is lacking. Supplementing wearable technologies with intervention content that evokes enjoyment, interest, meaning, and personal values associated with PA may support long term adherence. In this paper, we present the protocol of an NIA-funded study designed to evaluate the efficacy of CHALLENGE for increasing step count and motivation for PA in insufficiently active older women (Challenges for Healthy Aging: Leveraging Limits for Engaging Networked Game-based Exercise). CHALLENGE uses social media to supplement wearable activity monitors with the autonomy-supportive frame of a game. We hypothesize that CHALLENGE will engender playful experiences that will improve motivation for exercise and lead to sustained increases in step count.

METHODS

We will recruit 300 healthy, community dwelling older adult women on a rolling basis and randomize them to receive either the CHALLENGE intervention (experimental arm) or an activity monitor-only intervention (comparison arm). Participants in both groups will receive a wearable activity monitor and personalized weekly feedback emails. In the experimental group, participants will also be added to a private Facebook group, where study staff will post weekly challenges that are designed to elicit playful experiences while walking. Assessments at baseline and 6, 12, and 18 months will measure PA and motivation-related constructs. We will fit linear mixed-effects models to evaluate differences in step count and motivational constructs, and longitudinal mediation models to evaluate if interventional effects are mediated by changes in motivation. We will also conduct thematic content analysis of text and photos posted to Facebook and transcripts from individual interviews.

DISCUSSION

By taking part in a year-long intervention centered on imbuing walking behaviors with playful and celebratory experiences, participating older adult women may internalize changes to their identity and relationship with PA that facilitate sustained behavior change. Study results will have implications for how we can harness powerful and increasingly ubiquitous technologies for health promotion to the vast and growing population of older adults in the U.S. and abroad.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT04095923. Registered September 17th, 2019.

Does cross-education minimize the loss of muscle force and power and sEMG amplitude during short-term detraining in older women who are recreationally engaged in resistance training?

This study aimed to investigate whether 4 weeks of unilateral resistance training (RT) could attenuate the decline in muscle function in the contralateral limb of older women recreationally engaged in RT compared to control group (CTL). Twenty-four participants completed a 10-week RT before the cross-education (CR-Edu) phase and subsequent detraining. Afterward, participants were randomized into two groups: CTL (n = 8 women, n = 16 legs) who underwent 4 weeks of detraining without any training, and CR-Edu (n = 16 women, n = 16 legs) who performed 4 weeks of unilateral RT. Muscle force, power, and surface electromyography were measured unilaterally before and after the 4-week period, using five repetitions conducted at 40% and 60% of the 1RM. The results showed a reduction in muscle force at both 40% and 60% of 1RM, as well as a decrease in power at 60% of 1RM (P-time < 0.05) without significant differences between the two groups (P interaction > 0.05). There was a decline in power at 60% of 1RM (P-time < 0.05) but no significant change at 40% of 1RM (P-time > 0.05), and again, no significant differences were observed between the groups (P-interaction > 0.05). The surface electromyography of vastus lateralis decreased only in the CTL group (P-interaction < 0.05). Older women recreationally engaged in RT who perform in unilateral leg extension compared to a brief period of detraining seem not to retain muscle force and power, and sEMG amplitude of their homologous and contralateral limb.

Effects of Exercise, Rehabilitation, and Nutritional Approaches on Body Composition and Bone Density in People with Multiple Sclerosis: A Systematic Review and Meta-Analysis

People with multiple sclerosis (pwMS) are affected by a wide range of disabilities, including a decrease in bone mineral density (BMD) and a worsening of body composition (BC), which negatively impact their quality of life quality. This study aims to analyze the effects of nonpharmacological interventions-in particular, physical activity, nutritional approaches, and rehabilitation-on BC and BMD in pwMS. This systematic review and meta-analysis was performed following the updated version of the PRISMA guidelines. In July 2022, five databases (MEDLINE, Embase, The Cochrane Library, Google Scholar, Web of Science) and gray literature were screened. Relevant articles published between 1 January 1990 and 1 September 2022 in any language were included. Outcomes of interest were anthropometric, BC measures, and BMD. The RoB 2.0 tool was used to assess the risk of bias. After duplicates elimination, 1120 records were screened, and 36 studies were included. A total of 25 articles were focused on physical activity and rehabilitation, 10 on nutrition, and 1 on multimodal intervention. One-third of the studies were judged to be at high risk of bias. The meta-analysis showed a high degree of heterogeneity due to the high variability in disease severity and intervention duration, intensity, frequency, and type. In general, no intervention showed consistent positive effects on BC. However, the most promising interventions seemed to be high-intensity training and ketogenic diets. Only a few studies considered BMD, and the results are inconsistent. Nevertheless, more studies are needed in order to confirm these results.

Construct validity of movement-evoked pain operational definitions in older adults with chronic low back pain

OBJECTIVE

Movement-evoked pain (MeP) may predispose the geriatric chronic low back pain (LBP) population to health decline. As there are differing operational definitions for MeP, the question remains as to whether these different definitions have similar associations with health outcomes in older adults with chronic LBP.

DESIGN

Cross-sectional analysis of an observational study.

SETTING

Clinical research laboratory.

SUBJECTS

226 older adults with chronic LBP.

METHODS

This secondary analysis used baseline data from a prospective cohort study (n = 250). LBP intensity was collected before and after the repeated chair rise test, stair climbing test, and 6-minute walk test; MeP change scores (ie, sum of pretest pain subtracted from posttest pain) and aggregated posttest pain (ie, sum of posttest pain) variables were calculated. LBP-related disability and self-efficacy were measured by the Quebec Back Pain Disability Scale (QBPDS) and Low Back Activity Confidence Scale (LOBACS), respectively. Physical function was measured with the Health ABC Performance Battery. Robust regression with HC3 standard errors was used to evaluate adjusted associations between both MeP variables and disability, self-efficacy, and physical function.

RESULTS

Greater aggregated posttest MeP was independently associated with worse disability (b = 0.593, t = 2.913, P = .004), self-efficacy (b = -0.870, t = -3.110, P = .002), and physical function (b = -0.017, t = -2.007, P = .039). MeP change scores were not associated with any outcome (all P > .050).

CONCLUSIONS

Aggregate posttest MeP was linked to poorer health outcomes in older adults with chronic LBP, but MeP change scores were not. Future studies should consider that the construct validity of MeP paradigms partially depends on the chosen operational definition.

Sex-specific associations between cardiovascular risk factors and physical function: the Gambian Bone and Muscle Ageing Study

BACKGROUND

In Sub-Saharan Africa, the prevalence of obesity, cardiovascular disease (CVD) and impaired physical function are increasing due to rapid urbanization. We investigated sex differences in associations between cardiac workload, arterial stiffness, peripheral vascular calcification (PVC) and physical function in Gambian adults.

METHODS

A total of 488 Gambians aged 40-75+ years were recruited (men: 239; and women: 249). Supine blood pressure and heart rate were measured to calculate rate pressure product and pulse pressure. Presence of PVC was determined from tibia peripheral quantitative computed tomography scans. Physical function was assessed by chair rise test (CRT), single two-legged jump (s2LJ) and hand grip strength (HGS). Body composition was measured by dual-energy x-ray absorptiometry; body size corrections were used to calculate fat mass index (FMI) and appendicular lean mass index (ALMI). Estimated glomerular filtration rate (eGFR) was measured from fasting blood samples. The relationship between rate pressure product, pulse pressure or presence of PVC (independent variable) with physical function parameters (dependent variable) was tested using linear regression. Sex-interactions were tested (p-int) adjusting for age, eGFR and ALMI/FMI. Results were expressed as mean differences between men and women with 95% confidence intervals. Mediation analyses used ALMI/FMI as mediator.

RESULTS

Women weighed less (54.7 kg ± 10.3 vs. 59.9 kg ± 10.3) and were shorter (157.8 cm ± 6.0 vs. 169.2 cm ± 7.0) compared with men (both P < 0.0001). Women had higher FMI (6.8 kg/m2  ± 2.9 vs. 2.9 kg/m2  ± 2.0, P < 0.0001) and eGFR (263.7 mL/min/1.73 m2  ± 133.1 vs. 237.6 mL/min/1.73 m2  ± 134.6), but lower ALMI (6.2 kg/m2  ± 0.7 vs. 8.02 kg/m2  ± 1.0, P < 0.0001) compared with men. There were significant mean differences between men and women in rate pressure product and s2LJ power (-1.08 [-1.21, -0.95]) and force (-0.57 [-0.63, -0.51]), only after adjusting for age, eGFR and FMI. There were significant mean differences in the associations between pulse pressure and CRT power (-0.28 [-0.31, -0.25]), s2LJ power (-1.07 [-1.20, -0.93]) and HGS (-11.94 [-13.35, -10.54]); these differences were greater after adjusting for age, eGFR and FMI, than ALMI. There were similar differences in the associations between PVC and physical function parameters. In men, FMI mediated the association between rate pressuree product and CRT power (P = 0.002), s2LJ force (P < 0.001) and s2LJ power (P = 0.001). ALMI did not mediate associations for either men or women.

CONCLUSIONS

Multiple risk factors for CVD were associated with poorer physical function in men and were mediated by FMI. There is a need to identify strategies to slow/prevent the rising CVD burden and poor physical function in Sub-Saharan Africa.

Physical Activity Type and Intensity Are Associated With Abdominal Muscle Area and Density: The Multiethnic Study of Atherosclerosis

BACKGROUND

Using data from a multiethnic cohort, the authors tested associations of multiple types and intensities of physical activity (PA) with abdominal muscle area and density.

METHODS

1895 Multiethnic Study of Atherosclerosis participants (mean age 64.6 [9.6] y) completed health history and PA questionnaires and computed tomography to quantify body composition and measurements of cardiovascular and inflammatory biomarkers. Analyses included multivariable regression.

RESULTS

Compared with those not meeting PA guidelines for Americans, those meeting the guidelines had higher total abdominal muscle area (odds ratio, 95% confidence interval 1.60, 1.20 to 2.15), stability muscle area (1.68, 1.28 to 2.20), and stability muscle density (1.35, 1.03 to 1.76). After adjustment for relevant covariates, each SD increase in total moderate to vigorous PA was associated with a higher total abdominal (β, 95% confidence interval = 0.068, 0.036 to 0.173), stability (0.063, 0.027 to 0.099), and locomotor (0.069, 0.039 to 0.099) muscle area and higher locomotor muscle density (0.065, 0.022 to 0.108, P < .01). Only intentional and conditioning exercise were associated with total abdominal and stability muscle density (P < .05). Light PA and walking were not associated with muscle area or density.

CONCLUSIONS

Most types of PA are positively associated with abdominal muscle area and density across functional categories, independent of relevant covariates. These results provide additional evidence for promoting PA for healthy muscle aging.

Muscle Quality of Knee Extensors Based on Several Types of Force in Multiple Sclerosis Patients with Varying Degrees of Disability

Background and Objectives: Multiple sclerosis (MS) tends to affect muscle performance, mainly in the lower extremities. The degree of disability is associated with the loss of strength and muscle mass, to varying extents. Muscle quality (MQ) expresses the amount of force produced relative to the activated muscle mass. The purpose of this study was to compare the MQ of the knee extensors in the main manifestations of strength (isometric, dynamic strength, and power) among patients with differing degrees of neurological disability and evolutionary forms of the disease. We also establish reference values for MQ in MS patients (pwMS). Materials and Methods: In total, 250 pwMS were evaluated according to the Expanded Disability Status Scale (EDSS). The maximum dynamic and isometric forces and muscle power manifested a load of 60% of the maximum dynamics of the knee extensors. The lean mass of the thigh and hip was determined by densitometry, and the MQ was calculated for the three types of force evaluated. Results: The pwMS with relapsing remitting MS (RRMS) presented isometric MQ values that were 15.8% better than those of pwMS with primary progressive MS (PPMS) and 13.8% better than those of pwMS with secondary progressive MS (SPMS). For pwMS with SPMS, the dynamic MQ was 16.7% worse than that of patients with RRMS, while the power MQ was 29.5% worse. By degree of disability (<4 >7.5 EDSS score), patients with better MQ had mild EDSS scores, and patients with severe EDSS scores had 24.8%, 25.9%, and 40.3% worse isometric, dynamic, and power MQ scores, respectively, than those with RRMS. Based on these results, reference values for MQ in pwMS were established. Conclusions: The pwMS with different types of MS do not show differences in lean mass or strength but do show differences in MQ. In pwMS with different EDSS grades, there are no differences in lean mass, but there are differences in strength based on MQ, especially power MQ.

A Standardized Assessment of Movement-evoked Pain Ratings Is Associated With Functional Outcomes in Older Adults With Chronic Low Back Pain

OBJECTIVE

Despite high prevalence estimates, chronic low back pain (CLBP) remains poorly understood among older adults. Movement-evoked pain (MeP) is an understudied factor in this population that may importantly contribute to disability. This study investigated whether a novel MeP paradigm contributed to self-reported and performance-based function in older adults with CLBP.

MATERIALS AND METHODS

This secondary analysis includes baseline data from 230 older adults with CLBP in the context of a prospective cohort study. The Repeated Chair Rise Test, Six Minute Walk Test, and Stair Climbing Test were used to elicit pain posttest LBP ratings were aggregated to yield the MeP variable. Self-reported and performance-based function were measured by the Late Life Function and Disability Index (LLFDI) scaled function score and Timed Up-and-Go Test (TUG), respectively. Robust regression with HC3 standard errors was used to model adjusted associations between MeP and both functional outcomes; age, sex, body mass index, and pain characteristics (ie, intensity, quality, and duration) were utilized as covariates.

RESULTS

MeP was present in 81.3% of participants, with an average rating of 5.09 (SD=5.4). Greater aggregated posttest MeP was associated with decreased LLFDI scores (b=-0.30, t=-2.81, P=0.005) and poorer TUG performance (b=0.081, t=2.35, P=0.020), independent of covariates. LBP intensity, quality and duration were not associated with the LLFDI or TUG, (all P>0.05).

DISCUSSION

Aggregated posttest MeP independently contributed to worse self-reported and performance-based function among older adults with CLBP. To understand long-term consequences of MeP, future studies should examine longitudinal associations between MeP and function in this population.

Mediating effect of muscle power on the relationship of physical activity with physical fitness and physical function in older women

OBJECTIVE

This study analyzed if the associations of physical activity with physical fitness and physical function in older women are mediated by muscle power.

METHODS

Participants were 54 older women (age 73.5 ± 6.8 yrs). Moderate-to-vigorous intensity physical activity (min day^-1) was measured by accelerometry. Lower limb muscle power (W/kg) was estimated from a single two-leg countermovement jump performed on a force platform. Physical fitness (lower body strength, agility/dynamic balance, and aerobic endurance) was objectively assessed through the Senior Fitness Test Battery, respectively: 30s chair stand (repetitions), 8-ft up-and-go (s), and 6-min walk test (m). Physical function was subjectively evaluated via the 12-item Composite Physical Function Scale Questionnaire (score). Mediation effects were estimated using bootstrapped 95% confidence intervals and were deemed significant if 0 was not included in the intervals.

RESULTS

Mediation analysis controlling to age revealed an indirect effect of moderate-to-vigorous intensity physical activity through muscle power on all physical fitness components, specifically lower body strength (B = 0.048, 95% BootCI [0.013, 0.114]), agility/dynamic balance (B = -0.009, 95% BootCI [-0.024, -0.002]) and aerobic endurance (B = 0.656, 95% BootCI [0.142, 1.597]) and on physical function global score (B = 0.040 95% BootCI [0.009, 0.094]).

CONCLUSIONS

These results suggest that physical activity of at least moderate intensity is relevant to daily functional competence, by promoting the maintenance or improvement of muscle power.

Using the Behaviour Change Wheel Program Planning Model to Design Games for Health: Development Study

Background

Games for health are a promising approach to health promotion. Their success depends on achieving both experiential (game) and instrumental (health) objectives. There is little to guide game for health (G4H) designers in integrating the science of behavior change with the art of game design.

Objective

The aim of this study is to extend the Behaviour Change Wheel program planning model to develop Challenges for Healthy Aging: Leveraging Limits for Engaging Networked Game-Based Exercise (CHALLENGE), a G4H centered on increasing physical activity in insufficiently active older women.

Methods

We present and apply the G4H Mechanics, Experiences, and Change (MECHA) process, which supplements the Behaviour Change Wheel program planning model. The additional steps are centered on identifying target G4H player experiences and corresponding game mechanics to help game designers integrate design elements and G4H objectives into behavioral interventions.

Results

We identified a target behavior of increasing moderate-intensity walking among insufficiently active older women and key psychosocial determinants of this behavior from self-determination theory (eg, autonomy). We used MECHA to map these constructs to intervention functions (eg, persuasion) and G4H target player experiences (eg, captivation). Next, we identified behavior change techniques (eg, framing or reframing) and specific game mechanics (eg, transforming) to help realize intervention functions and elicit targeted player experiences.

Conclusions

MECHA can help researchers map specific linkages between distal intervention objectives and more proximal game design mechanics in games for health. This can facilitate G4H program planning, evaluation, and clearer scientific communication.

Sex-Specific Associations Between Bone-Loading Score and Adiposity Markers in Middle-Aged and Older Adults

The authors examined sex-specific relationships between fat mass index (FMI), android/gynoid (A/G) fat ratio, relative skeletal muscle mass index, and Bone-Specific Physical Activity Questionnaire derived bone-loading scores (BLSs) in middle-aged and older adults (men, n = 27; women, n = 33; age = 55-75 years). The FMI, A/G fat ratio, and relative skeletal muscle mass index were estimated by dual-energy X-ray absorptiometry. The Bone-Specific Physical Activity Questionnaire was used to assess: (a) BLSpast (age 1 until 12 months before the study visit), (b) BLScurrent (last 12 months), and (c) BLStotal (average of [a] and [b]) scores. Separate multiple linear regression analysis of (a) age, FMI, and relative skeletal muscle mass index and (b) age, height, and A/G fat ratio versus BLS revealed that FMI and A/G fat ratio were negatively associated with BLSpast and BLStotal (p < .05) in women only. Adiposity and, specifically, central adiposity is negatively related to bone-loading physical activity in middle-aged and older women.

Exercise interventions, physical function, and mobility after hip fracture: a systematic review and meta-analysis

PURPOSE

To investigate the effects of different exercise components on physical function and mobility in adults after hip fracture.

METHODS

Pubmed, Embase, Cochrane Library, Web of Science, CINAHL, and PsycINFO were searched up to March 2021. Randomized controlled trials investigating the effects of exercise interventions on physical function and mobility in adults after hip fracture were included.

RESULTS

Fifteen studies (12 trials) were included (n = 1198, age = 80 ± 8 years). Exercise interventions had a moderate effect on overall physical function after hip fracture compared to non-exercise (SMD = 0.46, 95% CI = 0.27-0.65). Among different exercise components, progressive resistance exercise showed the largest effect (SMD = 0.48, 95% CI = 0.27-0.69), while aerobic exercise alone had no effect (SMD 0.41, 95% -0.44 to1.26) on physical function. Exercise had a small effect on mobility (SMD = 0.28, 95% CI = 0.12-0.43). Specifically, functional exercise showed a moderate effect (SMD = 0.41, 95% CI = 0.16-0.65) on mobility.

CONCLUSIONS

Available evidence supports that exercise interventions improve physical function and mobility in older adults after hip fracture; specifically, resistance exercise with progressive load of 60-80% 1RM, and functional exercise may be critical intervention components respectively. Future high-quality research is needed to establish best practices.IMPLICATIONS FOR REHABILITATIONProgressive resistance exercise with 60-80% 1RM resulted in the largest improvement in physical function after hip fracture.Functional exercise appears to be a critical component for improving mobility after hip fracture. Functional exercise plus resistance and balance exercises was the most effective intervention for enhancing mobility.Exercise should be supervised by a trainer or a physiotherapist, and self-reported exercise may not result in the same benefits.

Effects of Short- and Long-Term Aerobic-Strength Training and Determinants of Walking Speed in the Elderly

BACKGROUND/AIMS

Walking speed (WS) is an objective measure of physical capacity and a modifiable risk factor of morbidity and mortality in the elderly. In this study, we (i) determined effects of 3-month supervised aerobic-strength training on WS, muscle strength, and habitual physical activity; (ii) evaluated capacity of long-term (21 months) training to sustain higher WS; and (iii) identified determinants of WS in the elderly.

METHODS

Volunteers (F 48/M 14, 68.4 ± 7.1 years) completed either 3-month aerobic-strength (3 × 1 h/week, n = 48) or stretching (active control, n = 14) intervention (study A). Thirty-one individuals (F 24/M 7) from study A continued in supervised aerobic-strength training (2 × 1 h/week, 21 months) and 6 (F 5/M 1) became nonexercising controls.

RESULTS

Three-month aerobic-strength training increased preferred and maximal WS (10-m walk test, p < 0.01), muscle strength (p < 0.01) and torque (p < 0.01) at knee extension, and 24-h habitual physical activity (p < 0.001), while stretching increased only preferred WS (p < 0.03). Effect of training on maximal WS was most prominent in individuals with baseline WS between 1.85 and 2.30 m·s-1. Maximal WS measured before intervention correlated negatively with age (r = -0.339, p = 0.007), but this correlation was weakened by the intervention (r = -0.238, p = 0.06). WS progressively increased within the first 9 months of aerobic-strength training (p < 0.001) and remained elevated during 21-month intervention (p < 0.01). Cerebellar gray matter volume (MRI) was positively associated with maximal (r = 0.54; p < 0.0001) but not preferred WS and explained >26% of its variability, while age had only minor effect.

CONCLUSIONS

Supervised aerobic-strength training increased WS, strength, and dynamics of voluntary knee extension as well as habitual physical activity in older individuals. Favorable changes in WS were sustainable over the 21-month period by a lower dose of aerobic-strength training. Training effects on WS were not limited by age, and cerebellar cortex volume was the key determinant of WS.

Walking-friendly built environments and objectively measured physical function in older adults

BACKGROUND

Few studies have examined the associations between urban design attributes and older adults' physical function. Especially, it is not well known how built-environment attributes may influence physical function in Asian cities. The aim of this study was to examine associations between objectively measured environmental attributes of walkability and objectively assessed physical function in a sample of Japanese older adults.

METHODS

Cross-sectional data collected in 2013 from 314 older residents (aged 65-84 years) living in Japan were used. Physical function was estimated from objectively measured upper- and lower-body function, mobility, and balance by a trained research team member. A comprehensive list of built-environment attributes, including population density, availability of destinations, intersection density, and distance to the nearest public transport station, were objectively calculated. Walk Score as a composite measure of neighborhood walkability was also obtained.

RESULTS

Among men, higher population density, availability of destinations, and intersection density were significantly associated with better physical function performance (1-legged stance with eyes open). Higher Walk Score was also marginally associated with better physical function performance (1-legged stance with eyes open). None of the environmental attributes were associated with physical function in elderly women.

CONCLUSION

Our findings indicate that environmental attributes of walkability are associated with the physical function of elderly men in the context of Asia. Walking-friendly neighborhoods can not only promote older adults' active behaviors but can also support their physical function.

The influence of isokinetic peak torque and muscular power on the functional performance of active and inactive community-dwelling elderly: a cross-sectional study

OBJECTIVE

To verify the importance of the isokinetic muscular torque and power of knee extensors and flexors on the functional performance of active and inactive elderly women.

METHODS

A cross-sectional observational study was conducted with 116 community-dwelling women (≥60 years old) without severe cognitive and/or motor dysfunction. Isokinetic muscle function was measured by peak torque and muscle power at 60°/s (5 repetitions) and 180°/s (15 repetitions), respectively. Mobility was evaluated by means of the Timed Up and Go test (TUG) and the Habitual Gait Speed (HGS) test. Balance was evaluated via the alternate step and semitandem tests. Lower limb strength was assessed using the Sit-to-stand test. Univariate and multivariate logistic regression analysis was used to determine association between independent and dependent variables (α=0.05).

RESULT

Active elderly women had better muscle function and functional performance than inactive elderly women for almost all variables. Peak torque and muscular power of knee extensor muscles explained the dynamic balance, mobility, and lower limb strength among inactive elderly women (OR: 0.89-0.95; p<0.05). Muscular power of knee flexors influenced tasks that required mobility and lower limb strength among active elderly (OR: 0.82-0.87; p<0.05).

CONCLUSIONS

The muscular power of knee flexors was shown to be more important for the functional performance of active elderly women. The muscular power of knee extensors had a stronger influence on the performance of the inactive elderly women.

Muscle quality index and isometric strength in older adults with hip osteoarthritis

Background

Older adults with hip osteoarthritis (OA) suffer a progressive loss of muscle quality and strength, affecting their daily activities and quality of life. The purpose of this study is to compare the levels of isometric strength among older adults with and without hip OA and healthy young adults, and to determine the relationship between muscle quality index (MQI) and isometric strength.

Methods

Fourteen subjects with hip OA (65.6 ± 3.0 years), 18 healthy older adults (66.6 ± 6.5 years) and 32 young adults (20.7 ± 2.0 years) participated in the study. MQI, isometric muscle strength of the hip, ten time sit-to-stand tests, and body composition were measured.

Results

The MQI was lower in subjects with hip OA, with no significant differences between groups (p > 0.054). Subjects with OA produced significantly less isometric strength in hip extension (p < 0.001), flexion (p < 0.001), abduction (p < 0.05), adduction (p < 0.001), external (p < 0.05) and internal rotation (p < 0.05). Subjects with OA demonstrated longer time in the execution of the sit-to-stand test (p < 0.001) in comparison with healthy older and young adults. High correlations between MQI, sit-to-stand (r =  - 0.76, p < 0.01) and peak force during hip abduction (r = 0.78, p < 0.01) where found in subjects with OA. Moderate correlation between MQI and peak force during hip flexion (r = 0.55, p < 0.05) and external rotation (r = 0.61, p < 0.05) were found in the OA group.

Conclusions

Subjects with OA have lower MQI than old and young healthy controls. In subjects with OA, there was a significant relationship between isometric strength of hip muscles and performance on the sit-to-stand test and the MQI.

Changes in Jumping and Throwing Performances in Age-Group Athletes Competing in the European Masters Athletics Championships between 1978 and 2017

The results of master athletes have been used previously to examine the age-related differences in aerobic capacity, however, less research has been conducted on the variation of jumping and throwing performances with aging. Therefore, the aim of the present study of elite master athletes was to investigate (a) the age-related differences in throwing (i.e., discus, hammer, javelin, and shot put) and jumping events (i.e., high jump, long jump, pole vault, and triple jump) in 5-year age-group intervals from 35-39 to 95-99 years of elite master athletes, and (b) the trends in performance and sex differences. The top eight female and male finalists for each age group and in each event from 20 European Masters Athletics Championships held between 1978 and 2017 were considered. Overall, 13,673 observations from 4726 master athletes were analyzed. For each event separately, a mixed regression model was performed with sex, age group, calendar year, and interaction terms (sex-age group, sex-year) defined as fixed effects. Performances were improving over time with a linear trend overall for each event. Men had better performances as compared to women, (i.e., in triple jump the estimated difference was 2.58 m, p < 0.001). Performances declined with age for each event (i.e., in triple jump, compared with the age group 45-49 years, performance in the age group 35-39 years was 0.98 m better and performance in the age group 85-89 years was 6.24 m worse). The decline of male performances with age was either slower or faster than the decline of female performances depending on age groups and events.

Sociodemographic Predictors of Physical Functioning in the Elderly: A National Health Survey

We aimed to evaluate the prevalence of sociodemographic factors with the presence and different degrees of walking difficulties in elderly above 65 years, and to analyze association between evaluated variables and the presence and degree of waking difficulties. In the population based study, 3540 individuals age above 65 years from Serbia were recruited. Further predictors were analyzed: gender, age, level of education, marital status, body mass index (BMI), index of well-being and place of residence. We assessed difficulty in walking half a km on level ground without the use of any aid (Group-1); and difficulty in walking up or down 12 steps (Group-2). Walking difficulties were categorized as no difficulty, some difficulty, a lot of difficulty and cannot do at all. For present difficulty significant predictors were: age (Group-1 (OR-3.022)/Group-2 (OR-3.825)), gender (Group-1 (OR-0.337)/Group-2 (OR-0.311)), educational level (Group-1 (OR-0.689)/Group-2 (OR-0.556)) and place of residence (Group-2 (OR-1.523)) while for non-performing the task, significant predictors were: age (Group-1 (OR-1.998)/Group-2 (OR-2.096)), gender (Group-1 (OR-0.629)/Group-2 (OR-0.495)), BMI (Group-1 (OR-1.219)/Group-2 (OR-1.305)), marital status (Group-1 (OR 0.764)/Group-2 (OR-0.769)), educational level (Group-1 (OR-0.679)/Group-2 (OR-0.719)) and index of well-being (Group-2 (OR-0.764)). Understanding of predictors, and their role on functional decline in elderly is of great importance for the development of specific population-based health programs to prevent further functional loss and preserve achieved functional gains.

Reduced body weight or increased muscle quality: Which is more important for improving physical function following exercise and weight loss in overweight and obese older women?

The purpose of this study was to examine the relative contributions of changes in muscle quality and body composition to changes in lower-extremity physical function (LEPF) following a 6-month exercise and weight loss intervention in overweight and obese older women. Thirty-eight overweight and obese (BMI = 30.0 ± 4.4 kg/m²) older (age = 69.3 ± 4.1 y) women completed 6 months of multicomponent exercise (cardiorespiratory, resistance, balance and flexibility training) and weight loss (hypocaloric diet that reduced energy intake by ~500 kcal/d). Body composition was measured via dual-energy X-ray absorptiometry and muscle quality (N-m/kg) was defined as maximal concentric isokinetic knee torque divided by upper-leg lean mass. The standardized scores of four objective measures of physical function were summed to yield a composite LEPF Z-score. At 6 months, there were significant reductions in body weight (-9.6 ± 3.5%, p < 0.01), absolute fat mass (-6.8 ± 2.4 kg, p < 0.01) and relative adiposity (-4.9 ± 2.1%, p < 0.01). There were also improvements in both muscle quality (+1.6 ± 1.8 N-m/kg, p < 0.01) and individual measures of LEPF (11-57%, p < 0.01). Multivariate linear regression indicated that increased muscle quality was the strongest independent predictor of an improvement in LEPF Z-score (standardized β = 0.64, p < 0.01) and explained 34% of the variance. A reduction in body weight also predicted an improvement in LEPF, independent of the change in muscle quality. In conclusion, muscle quality can be increased in the presence of clinically meaningful weight loss, and is the primary determinant of improved physical function in overweight/obese older women.

Muscular responses to testosterone replacement vary by administration route: a systematic review and meta-analysis

BACKGROUND

Inconsistent fat-free mass (FFM) and muscle strength responses have been reported in randomized clinical trials (RCTs) administering testosterone replacement therapy (TRT) to middle-aged and older men. Our objective was to conduct a meta-analysis to determine whether TRT improves FFM and muscle strength in middle-aged and older men and whether the muscular responses vary by TRT administration route.

METHODS

Systematic literature searches of MEDLINE/PubMed and the Cochrane Library were conducted from inception through 31 March 2017 to identify double-blind RCTs that compared intramuscular or transdermal TRT vs. placebo and that reported assessments of FFM or upper-extremity or lower-extremity strength. Studies were identified, and data were extracted and validated by three investigators, with disagreement resolved by consensus. Using a random effects model, individual effect sizes (ESs) were determined from 31 RCTs reporting FFM (sample size: n = 1213 TRT, n = 1168 placebo) and 17 reporting upper-extremity or lower-extremity strength (n = 2572 TRT, n = 2523 placebo). Heterogeneity was examined, and sensitivity analyses were performed.

RESULTS

When administration routes were collectively assessed, TRT was associated with increases in FFM [ES = 1.20 ± 0.15 (95% CI: 0.91, 1.49)], total body strength [ES = 0.90 ± 0.12 (0.67, 1.14)], lower-extremity strength [ES = 0.77 ± 0.16 (0.45, 1.08)], and upper-extremity strength [ES = 1.13 ± 0.18 (0.78, 1.47)] (P < 0.001 for all). When administration routes were evaluated separately, the ES magnitudes were larger and the per cent changes were 3-5 times greater for intramuscular TRT than for transdermal formulations vs. respective placebos, for all outcomes evaluated. Specifically, intramuscular TRT was associated with a 5.7% increase in FFM [ES = 1.49 ± 0.18 (1.13, 1.84)] and 10-13% increases in total body strength [ES = 1.39 ± 0.12 (1.15, 1.63)], lower-extremity strength [ES = 1.39 ± 0.17 (1.07, 1.72)], and upper-extremity strength [ES = 1.37 ± 0.17 (1.03, 1.70)] (P < 0.001 for all). In comparison, transdermal TRT was associated with only a 1.7% increase in FFM [ES = 0.98 ± 0.21 (0.58, 1.39)] and only 2-5% increases in total body [ES = 0.55 ± 0.17 (0.22, 0.88)] and upper-extremity strength [ES = 0.97 ± 0.24 (0.50, 1.45)] (P < 0.001). Interestingly, transdermal TRT produced no change in lower-extremity strength vs. placebo [ES = 0.26 ± 0.23 (-0.19, 0.70), P = 0.26]. Subanalyses of RCTs limiting enrolment to men ≥60 years of age produced similar results.

CONCLUSIONS

Intramuscular TRT is more effective than transdermal formulations at increasing LBM and improving muscle strength in middle-aged and older men, particularly in the lower extremities.

Understanding Age-Related Changes in Skeletal Muscle Metabolism: Differences Between Females and Males

Skeletal muscle is the largest metabolic organ system in the human body. As such, metabolic dysfunction occurring in skeletal muscle impacts whole-body nutrient homeostasis. Macronutrient metabolism changes within the skeletal muscle with aging, and these changes are associated in part with age-related skeletal muscle remodeling. Moreover, age-related changes in skeletal muscle metabolism are affected differentially between males and females and are likely driven by changes in sex hormones. Intrinsic and extrinsic factors impact observed age-related changes and sex-related differences in skeletal muscle metabolism. Despite some support for sex-specific differences in skeletal muscle metabolism with aging, more research is necessary to identify underlying differences in mechanisms. Understanding sex-specific aging skeletal muscle will assist with the development of therapies to attenuate adverse metabolic and functional outcomes.

Short- and long-term reliability of leg extensor power measurement in middle-aged and older adults

Muscular power is important for maintaining physical functioning with aging. Proper quantification of the reliability of muscular power tests is crucial to inform monitoring of individuals and sample size planning for interventional studies. This study evaluated short- and long-term reliability of leg extensor power measurement in 72 adults (age 62.7 ± 8.6 years). Participants completed four repeat trials on the Nottingham leg extensor power rig, with a further trial twelve weeks later. Mean change, typical error, and intraclass correlation coefficients (ICC) were calculated. For short-term reliability, mean change in power output was trivial after two trials (1.2-4.8%). Typical errors were small following four trials in the dominant leg of males (10.9-5.8%), three in the non-dominant leg of males (9.9-6.2%) and the dominant leg of females (10.0-9.6%) and two in the non-dominant leg in females (8.3%). Intraclass correlation coefficients (ICCs) were very high (0.88-0.96). For long-term reliability, mean change remained trivial (1.0-2.5%), typical errors remained small (5.8-8.6%), and ICCs very high (0.94-0.96). The leg extensor power rig is a reliable method for assessing lower body muscular power, both short- and long-term, with only minimal habituation effects.

The Need for Standardized Assessment of Muscle Quality in Skeletal Muscle Function Deficit and Other Aging-Related Muscle Dysfunctions: A Symposium Report

A growing body of scientific literature suggests that not only changes in skeletal muscle mass, but also other factors underpinning muscle quality, play a role in the decline in skeletal muscle function and impaired mobility associated with aging. A symposium on muscle quality and the need for standardized assessment was held on April 28, 2016 at the International Conference on Frailty and Sarcopenia Research in Philadelphia, Pennsylvania. The purpose of this symposium was to provide a venue for basic science and clinical researchers and expert clinicians to discuss muscle quality in the context of skeletal muscle function deficit and other aging-related muscle dysfunctions. The present article provides an expanded introduction concerning the emerging definitions of muscle quality and a potential framework for scientific inquiry within the field. Changes in muscle tissue composition, based on excessive levels of inter- and intra-muscular adipose tissue and intramyocellular lipids, have been found to adversely impact metabolism and peak force generation. However, methods to easily and rapidly assess muscle tissue composition in multiple clinical settings and with minimal patient burden are needed. Diagnostic ultrasound and other assessment methods continue to be developed for characterizing muscle pathology, and enhanced sonography using sensors to provide user feedback and improve reliability is currently the subject of ongoing investigation and development. In addition, measures of relative muscle force such as specific force or grip strength adjusted for body size have been proposed as methods to assess changes in muscle quality. Furthermore, performance-based assessments of muscle power via timed tests of function and body size estimates, are associated with lower extremity muscle strength may be responsive to age-related changes in muscle quality. Future aims include reaching consensus on the definition and standardized assessments of muscle quality, and providing recommendations to address critical clinical and technology research gaps within the field.

Sex Differences in Muscle Wasting

With aging and other muscle wasting diseases, men and women undergo similar pathological changes in skeletal muscle: increased inflammation, enhanced oxidative stress, mitochondrial dysfunction, satellite cell senescence, elevated apoptosis and proteasome activity, and suppressed protein synthesis and myocyte regeneration. Decreased food intake and physical activity also indirectly contribute to muscle wasting. Sex hormones also play important roles in maintaining skeletal muscle homeostasis. Testosterone is a potent anabolic factor promoting muscle protein synthesis and muscular regeneration. Estrogens have a protective effect on skeletal muscle by attenuating inflammation; however, the mechanisms of estrogen action in skeletal muscle are less well characterized than those of testosterone. Age- and/or disease-induced alterations in sex hormones are major contributors to muscle wasting. Hence, men and women may respond differently to catabolic conditions because of their hormonal profiles. Here we review the similarities and differences between men and women with common wasting conditions including sarcopenia and cachexia due to cancer, end-stage renal disease/chronic kidney disease, liver disease, chronic heart failure, and chronic obstructive pulmonary disease based on the literature in clinical studies. In addition, the responses in men and women to the commonly used therapeutic agents and their efficacy to improve muscle mass and function are also reviewed.

Effects of Resistance Training on Lower-Extremity Muscle Power in Middle-Aged and Older Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Resistance training (RT) has been investigated as a potential intervention strategy for improving muscle function, but the effects on lower-extremity muscle power in middle-aged and older adults have not been systematically reviewed.

OBJECTIVE

The aim of this meta-analysis is to provide a quantitative estimate of the effect of RT on lower-extremity muscle power in middle-aged and older adults and to examine independent moderators of this relationship.

METHODS

Randomized controlled trials that examined the effects of RT on either leg press (LP) or knee extension (KE) muscle power in adults aged ≥50 years were included. Data were aggregated with meta-analytic techniques, and multi-level modeling was used to adjust for nesting effects. A total of 52 effects from 12 randomized controlled trials were analyzed with a random-effects model to estimate the effect of RT on lower-extremity muscle power. A multiple-regression analysis was conducted to examine independent moderators of the mean effect.

RESULTS

The adjusted aggregated results from all studies indicate that RT has a small-to-moderate effect on lower-extremity muscle power (Hedges' d = 0.34, 95% confidence interval [CI] 0.25-0.43), which translated to 54.90 watts (95 % CI 40.37-69.43). Meta-regression analyses indicated that high-velocity RT was superior to traditional RT (Δ = 0.62 vs. 0.20, respectively) for increasing lower-extremity muscle power. In addition, training volume significantly moderated the effect of RT on muscle power.

CONCLUSION

The findings from this meta-analysis indicate that RT is an efficacious intervention strategy for improving LP and KE muscle power in adults aged ≥50 years. Training mode and volume independently moderate the effect of RT on lower-extremity muscle power, and should be considered when prescribing RT exercise for middle-aged and older adults.

Effect of resistance ladder training on sparc expression in skeletal muscle of hindlimb immobilized rats

INTRODUCTION

Secreted protein acidic and rich in cysteine (SPARC) is associated with skeletal muscle atrophy. Here we examined possibility that resistance training could regulate SPARC expression in muscle atrophy in an immobilized hindlimb model.

METHODS

Sprague-Dawley rats underwent resistance ladder training and hindlimb immobilization. Cross sectional area and grip strength were measured. SPARC protein levels in the plantaris and soleus, and serum after exercise and immobilization were then analyzed.

RESULTS

Resistance training decreased body weight (P < 0.001) and increased muscle quality (P < 0.001). In the plantaris, muscle atrophy (31.82%) and up-regulated SPARC expression (P < 0.05) after immobilization were alleviated by resistance training.

CONCLUSIONS

Resistance training led to suppression of SPARC expression in the plantaris and showed a pretraining effect in atrophied rat muscle. Thus, SPARC may play a pivotal role in muscle homeostasis. Muscle Nerve 53: 951-957, 2016.

Moderate-intensity physical activity is independently associated with lower-extremity muscle power in older women

Skeletal muscle power is a salient determinant of physical function in older adults, but its relationship with habitual physical activity has not been well-characterized. The aim of this study was to examine the association between moderate-intensity physical activity and lower-extremity muscle power in community-dwelling older women. Older women (n = 96, mean age = 73.9 ± 5.6 years, mean body mass index = 26.5 ± 4.7 kg/m(2)) underwent assessments for body composition via dual-energy X-ray absorptiometry and lower-extremity muscle power (watts) using the Nottingham power rig. The Community Health Activities Model Program for Seniors questionnaire was used to estimate weekly caloric expenditure in moderate-intensity physical activity (kcals/wk). Linear regression indicated that moderate-intensity physical activity was independently related to muscle power (standardized β = 0.20, p = .03), and this relationship remained following adjustment for covariates. Analysis of covariance revealed that women in the highest tertile of volume of physical activity had significantly greater muscle power than those with the lowest volume (199.0 vs. 170.7 watts, p < .05). Moderate-intensity physical activity was independently associated with lower-extremity muscle power in older women. Future intervention trials should determine if increasing habitual physical activity is associated with improvements in lower-extremity muscle power in older women.

Asymmetry in leg extension power impacts physical function in community-dwelling older women

OBJECTIVE

The aim of this study was to examine the association between asymmetry in leg extension power (LP) and lower-extremity physical function (LEF) in community-dwelling older women.

METHODS

Older women (n = 94, 74.0 ± 5.5 y) were assessed for unilateral LP (watts) using the Nottingham power rig, and absolute and relative (%ASYM) differences in LP between the dominant and nondominant legs were calculated. LEF was assessed via the 6-minute walk, 8-foot up-and-go and 30-second chair stand, and a composite measure of LEF was calculated by summing z scores of each test. In addition, body composition was measured via dual-energy x-ray absorptiometry and moderate-intensity physical activity was assessed via questionnaire.

RESULTS

The absolute difference in LP between the dominant and nondominant legs was 10.2 ± 9.0 watts, which translated to a %ASYM of 11.3% ± 10.5% (P < 0.01). %ASYM had bivariate associations with all individual measures of LEF (r range = -0.22 to -0.34, all P < 0.05). Using multivariate linear regression, %ASYM was an independent predictor of a composite LEF z score (standardized β= -0.18, P < 0.05) after adjustment for age, comorbidities, physical activity, relative adiposity, and total leg power. Analysis of covariance indicated that women with low asymmetry had a significantly better LEF z score than those with high asymmetry (0.60 vs -0.13, P = 0.04).

CONCLUSIONS

These findings indicate that a greater magnitude of asymmetry in LP is associated with poorer LEF in older women. Research is needed to determine whether interventions that correct asymmetries in lower-body muscle power confer functional benefits in older women.