Resistance training increases total energy expenditure and free-living physical activity in older adults

Effects of exercise on body mass index and waist circumference of individuals with intellectual and developmental disabilities: a systematic review with meta-analysis

Introduction/Methods: This systematic review with meta-analysis aims to assess the magnitude of the effects of physical exercise programs on body mass index (BMI) and waist circumference (WC) of individuals with Intellectual and Developmental Disabilities (IDD), metabolic and cardiovascular health markers. Results: Considering the eligibility criteria, a final sample of nine articles was obtained. For BMI, the Z-value obtained to test the null hypothesis (difference between means is zero), showed a Z = -2.176 and p = 0.03. The highest magnitude of the effect was from the intervention with combined training (difference in means: -0.399), with a value of Z = -1.815 and p = 0.07. For WC, the Z-value is zero, showing a Z = -3.306 and p = 0.001. The highest magnitude of the effect was from the intervention with continuous cardiorespiratory training of -0.786, with a value of Z = -2.793 and p = 0.005. Discussion: Physical exercise prevents increases in BMI and WC in individuals with IDD. Aerobic training seems to be more effective in promoting WC and combined training in BMI. Systematic Review Registration: [PROSPERO], identifier [CRD42021255316].

The Effects of an Acute Bout of Aerobic or Resistance Exercise on Nonexercise Physical Activity

Introduction/Purpose

A reduction in nonexercise physical activity (NEPA) after exercise may reduce the effectiveness of exercise interventions on weight loss in adults with overweight or obesity. Aerobic exercise (AEx) and resistance exercise (REx) may have different effects on NEPA. The purpose of this secondary analysis was to examine the effect of a single bout of AEx or REx on NEPA and sedentary behavior in inactive adults with overweight or obesity.

Methods

Adults with overweight or obesity (n = 24; 50% male; age, 34.5 ± 1.5 yr; body mass index, 28.5 ± 0.9 kg·m-2) not meeting current physical activity guidelines completed a single 45-min bout of AEx, REx, or a sedentary control on different days in random order. After each condition, participants' NEPA was recorded for 84 h by accelerometer. Time spent sedentary and in light, moderate, and vigorous physical activity; steps; metabolic equivalent of task (MET)-hours; and sit-to-stand transitions were calculated using activity count data.

Results

No differences were observed in the percent of waking time spent sedentary and in light, moderate, and vigorous activity between conditions (P > 0.05). No differences were observed in steps, MET-hours, or sit-to-stand transitions between conditions (P > 0.05). NEPA responses were variable among individuals, with approximately half of participants reducing and half increasing NEPA over the 84 h after each exercise condition.

Conclusion

NEPA was not reduced after an acute bout of AEx or REx in a sample of inactive adults with overweight or obesity.

Factors related to hypermetabolism in individuals with type 2 diabetes mellitus and non-alcoholic fatty liver disease

Considering the progressive prevalence and co-occurrence of type 2 diabetes mellitus (T2DM) and non-alcoholic fatty liver disease (NAFLD), as well as the current evidence suggesting the elevated levels of basal metabolic rate (BMR) among these individuals, the present study aimed to identify factors determining hypermetabolism in such subjects. This cross sectional study was conducted in 30 to 53-year-old individuals with concurrent T2DM and NAFLD (controlled attenuation parameter score ≥ 260 dB/m). Resting energy expenditure (REE) was determined by an indirect calorimetry device. Hypermetabolism was defined as an elevated measured REE > 110% of the predicted REE. The multivariate logistic regression test was used for detecting factors associated with hypermetabolism. Between September, 2017, and March, 2018, a total of 95 eligible participants (64.40% male) with both T2DM and NAFLD were included, while 32.63% of them were classified as hypermetabolic. Overall, the mean recruitment age ± standard deviation and median (interquartile range) body mass index were 44.69 ± 5.47 years and 30.20 (27.80-33.30) kg/m², respectively. Demographic, anthropometric and biochemical variables did not vary significantly across two groups except for total body water, low-density lipoprotein cholesterol and dipeptidyl peptidase 4 (DPP-4) inhibitors (p < 0.05). According to the results of multivariable logistic regression analyses, hypermetabolism had a positive association with adiponectin (odds ratio [OR] 1.167, 95% confidence interval [CI] 1.015-1.342, p = 0.030), physical activity (OR 1.134, 95% CI 1.002-1.284, p = 0.046), alanine transaminase (OR 1.062, 95% CI 1.006-1.122, p = 0.031) and diastolic blood pressure (OR 1.067, 95% CI 1.010-1.127, p = 0.021). However, fat free mass was inversely related to hypermetabolism (OR 0.935, 95% CI 0.883-0.991, p = 0.023). Adiponectin, alanine transaminase, physical activity, diastolic blood pressure and fat free mass were independently associated with hypermetabolism in subjects with NAFLD and T2DM.

Relation of non-exercise walking activity with exercise performance in patients with peripheral artery disease: NEW activity for PAD

INTRODUCTION

Community-based structured exercise training (CB-SET) programs are beneficial for patients with peripheral artery disease (PAD). However, the impact of lower levels of walking activity accumulated separately from formal exercise is unclear. The aim of this study was to determine the relation of non-exercise walking (NEW) activity with exercise performance in PAD.

METHODS

This was a post hoc analysis from twenty patients with PAD enrolled in a 12 week CB-SET program using diaries and accelerometry. Formal exercise (3 sessions·week-1) was detected using patient-reported diary entries that corresponded with accelerometer step data. NEW activity was characterized as steps completed over five days each week, excluding steps achieved during formal exercise sessions. The primary exercise performance outcome was peak walking time (PWT) assessed on a graded treadmill. Secondary performance outcomes included claudication onset time (COT) from the graded treadmill and peak walking distance (PWD) achieved during the six-minute walk test (6MWT). Partial Pearson correlations evaluated the relation of NEW activity (step·week-1) with exercise performance outcomes using exercise session intensity (step·week-1) and duration (min·week-1) as covariates.

RESULTS

NEW activity demonstrated a moderate, positive correlation with change in PWT (r=0.50, p=0.04). Other exercise performance outcomes were not significantly related to NEW activity (COT: r=0.14; 6MWT PWD: r=0.27).

CONCLUSIONS

A positive association was demonstrated between NEW activity and PWT following 12 weeks of CB-SET. Interventions to increase physical activity levels outside of formal exercise sessions may be beneficial for patients with PAD.

Effects of resistance training on body recomposition, muscular strength, and phase angle in older women with different fat mass levels

AIMS

The concomitant increase in skeletal muscle mass (SMM) and decrease in fat mass has been termed body recomposition. This study aimed to analyze the influence of pre-training levels of fat mass on body recomposition, muscular strength, and (phase angle) PhA after 24 weeks of resistance training (RT) in older women.

METHODS

Data from 99 older women (68.6 ± 5.7 years, 65.7 ± 8.6 kg, 155.1 ± 5.8 cm, 27.2 ± 3.1 kg/m²) was retrospectively analyzed. Participants were separated into tertiles according to the amount of fat mass at baseline as follows: low fat mass (L-FM, n = 33), moderate fat mass (M-FM, n = 33), and high fat mass (H-FM, n = 33). The participants underwent a RT program consisting of eight exercises, three sets per exercise, with a load between 8 and 15 RM, performed three times per week for 24 weeks. The SMM and fat mass were evaluated by dual-energy X-ray absorptiometry (DXA). Body recomposition was determined by the composite Z-score of changes in SMM and fat mass. One repetition maximum (1RM) tests in chest press, knee extension, and preacher curl were assessed to verify muscular strength. Bioimpedance was used to determine phase angle.

RESULTS

Results indicated that after the RT period, a greater positive body recomposition was observed in the L-FM group than in M-FM and H-FM groups. Moreover, all groups increased muscular strength and phase angle with no significant difference among groups (P > 0.05).

CONCLUSION

The present study results suggest that the initial amount of fat mass influences the body recomposition induced by RT in older women, with those with lower pre-training fat mass levels presenting higher levels of body recomposition. However, improvements in muscular strength and phase angle are not dependent on the amount of initial fat mass in older women.

Metabolic adaptation after combined resistance and aerobic exercise training in older women

OBJECTIVE

This study investigated whether combined aerobic and resistance training in older women leads to metabolic adaptation.

METHODS

A total of 80 women (64 White individuals; BMI: 30.0 [4.4] kg/m² ; age: 64.8 [3.5] years) followed 32 weeks of aerobic and resistance training. Body weight/composition (dual-energy X-ray absorptiometry) and resting metabolic rate (RMR; indirect calorimetry) were measured at baseline, week 16, and week 32. Metabolic adaptation was defined as significantly lower measured versus predicted RMR. A regression model to predict metabolic adaptation was developed that included race, age, baseline fat-free mass, RMR and respiratory quotient, and changes in net submaximal oxygen consumption after different tasks.

RESULTS

There was significant metabolic adaptation at week 16 (-59 [136] kcal/d, p = 0.002), following a 640-kcal/wk energy loss (-0.7 [2.6] kg of weight loss). In 53 women with complete data, metabolic adaptation was seen both at week 16 (-64 [129] kcal/d, p = 0.001) and at week 32 (-94 [127] kcal/d, p < 0.001). Metabolic adaptation at week 16 was predicted by race, age, baseline fat-free mass, RMR and respiratory quotient, and change in net oxygen consumption of walking (R² adjusted = 0.90, p < 0.001). Similar results were seen at week 32.

CONCLUSIONS

In older women with overweight and obesity, a minimal energy deficit induced by aerobic and resistance exercise is associated with metabolic adaptation at the level of RMR.

A Metabolic Profile of Peripheral Heart Action Training

Purpose: Peripheral heart action (PHA) is a style of circuit training that alternates upper and lower body resistance exercises with minimal rest between sets. The purpose of this study was to compare the metabolic demands of PHA to traditional hypertrophy training (TRAD) and to provide between sex comparison for both types of resistance training (RT). Methods: Twenty resistance-trained individuals underwent two bouts of volume-load matched RT: PHA and TRAD. We measured oxygen uptake (VO₂), heart rate (HR), blood lactate (BL) concentration, rating of perceived exertion (RPE), excess post-exercise oxygen consumption (EPOC), and duration of each session. Results: PHA elicited significantly greater %VO₂max (p < .001), %HRmax (p < .001), RPE (p < .001), and EPOC (p < .001) compared to TRAD. PHA was also completed in less time (p < .001). Compared to TRAD, BL was significantly higher at mid-exercise (p < .001), post-exercise (p < .001), and 5-min post-exercise (p < .001) during PHA. There were no between-sex differences for BL at any time-point for TRAD. However, during PHA, BL was significantly higher for males at mid-exercise (p = .04), post-exercise (p = .02), and 5-min post-exercise (p = .002). No between-sex differences were detected for HR, VO₂, RPE, or duration for either style of RT. Conclusions: PHA is a time-effective and metabolically demanding circuit that may lead to strength and cardiorespiratory adaptations. Males produced more BL than females during PHA, but not TRAD, suggesting that they incurred more metabolic stress during the bout of circuit training.

Changes in 24-h energy expenditure, substrate oxidation, and body composition following resistance exercise and a high protein diet via whey protein supplementation in healthy older men

PURPOSE

To investigate changes in 24-h energy expenditure (EE), substrate oxidation, and body composition following resistance exercise (RE) and a high protein diet via whey protein supplementation (alone and combined) in healthy older men.

METHODS

In a pooled groups analysis, 33 healthy older men [(mean ± SE) age: 67 ± 1 years; BMI: 25.4 ± 0.4 kg/m2] were randomized to either RE (2×/week; n = 17) or non-exercise (n = 16) and either a high protein diet via whey protein supplementation (PRO, 2 × 25 g whey protein isolate/d; n = 17) or control (CON, 2 × 23.75 g maltodextrin/d; n = 16). An exploratory sub-analysis was also conducted between RE+CON (n = 8) and RE+PRO (n = 9). At baseline and 12 weeks, participants resided in respiration chambers for measurement of 24-h EE and substrate oxidation and wore an accelerometer for 7 days for estimation of free-living EE.

RESULTS

Resistance exercise resulted in greater increases in fat-free mass (1.0 ± 0.3 kg), resting metabolic rate [(RMR) 36 ± 14 kcal/d], sedentary EE (60 ± 33 kcal/d), and sleeping metabolic rate [(SMR) 45 ± 7 kcal/d] compared to non-exercise (p < 0.05); however, RE decreased activity energy expenditure in free-living (-90 ± 25 kcal/d; p = 0.049) and non-exercise activity inside the respiration chamber (-1.9 ± 1.1%; p = 0.049). PRO decreased fat mass [(FM) -0.5 ± 0.3 kg], increased overnight protein oxidation (30 ± 6 g/d), and decreased 24-h protein balance (-20 ± 4 g/d) greater than CON (p < 0.05). RE+PRO decreased FM (-1.0 ± 0.5 kg) greater than RE+CON (p = 0.04).

CONCLUSION

Resistance exercise significantly increased RMR, SMR, and sedentary EE in healthy older men, but not total EE. PRO alone and combined with RE decreased FM and aided body weight maintenance. This study was registered at clinicaltrials.gov as NCT03299972.

Moderate and Higher Protein Intakes Promote Superior Body Recomposition in Older Women Performing Resistance Training

PURPOSE

Resistance training (RT) combined with appropriate dietary intake can promote a concomitant increase in skeletal muscle mass (SMM) and reduction in fat mass, a condition termed body recomposition. This study's primary purpose was to explore the effects of protein ingestion on body recomposition after 24 wk of RT in older women.

METHODS

Data from 130 untrained older women (68.7 ± 5.6 yr, 66.5 ± 11.5 kg, 155.5 ± 6.0 cm, and 27.4 ± 4.0 kg·m-2) across six studies were retrospectively analyzed. The participants were divided into tertiles according to their customary protein intake (g·kg-1·d-1): lower (LP; n = 45), moderate (MP; n = 42), and higher (HP; n = 43) protein intake. Participants performed a whole-body RT program carried out over 24 wk (eight exercises, three sets, 8-15 repetitions, three sessions a week). SMM and fat mass were determined by dual-energy x-ray absorptiometry.

RESULTS

All groups increased SMM from baseline (P < 0.05), with the HP and MP groups showing greater increases than the LP group (LP, 2.3%; MP, 5.4%; and HP, 5.1%; P < 0.05). Reductions in fat mass were similar for all three groups (LP, 1.7%; MP, 3.7%; and HP, 3.1%; P > 0.05). The composite z-score of the percentage changes from pretraining to posttraining indicated greater positive body recomposition values for HP and MP compared with LP (P < 0.05).

CONCLUSIONS

Results suggest that protein intake is a moderating variable for body recomposition in older women undergoing RT, with a low protein intake having a less favorable effect on body recomposition.

ARTE index revisited: linking biomarkers of cardiometabolic health with free-living physical activity in postmenopausal women

Activity-related energy expenditure (AEE) correlates with physical activity volume; however, between-person differences in body size and walking economy (net V̇o2) can influence AEE. The ratio of total energy expenditure (TEE) and resting energy expenditure (REE) estimates physical activity level (PAL) relative to body mass, yet does not account for variance in walking economy. The activity-related time equivalent (ARTEwalk) circumvents such constraints by adjusting for individual-specific walking economy. Herein, we compared AEE, PAL, and ARTEwalk index in a cohort (n = 81) of postmenopausal women while examining possible associations with biomarkers of cardiometabolic health. Secondary analyses were performed on postmenopausal women dichotomized above/below age group 50th percentile for body fat percent. TEE was reduced by 10% for the thermogenesis of digestion wherein AEE was calculated by subtracting REE from adjusted TEE. PAL was calculated as the ratio of TEE/REE. AEE was divided by the mean net energy expenditure of nongraded walking to calculate the ARTEwalk index. Between-group differences were not detected for AEE or PAL. However, the ARTEwalk index revealed that participants with less adiposity were more physically active (258 ± 149 vs. 198 ± 115 min·day-1; P = 0.046; g = 0.46). AEE and PAL did not correlate with cardiorespiratory fitness or biomarkers of cardiometabolic health. Cardiorespiratory fitness (r = 0.32), arterial elasticity (r = 0.24), total cholesterol/HDL-c ratio (r = -0.22), and body fat% (r = -0.24) were correlated with ARTEwalk. The ARTEwalk index may offer utility in detecting possible differences in physical activity volume among postmenopausal women and appears better associated with cardiometabolic biomarkers compared with AEE or PAL.

The Mystery of Energy Compensation

AbstractThe received wisdom on how activity affects energy expenditure is that the more activity is undertaken, the more calories will have been burned by the end of the day. Yet traditional hunter-gatherers, who lead physically hard lives, burn no more calories each day than Western populations living in labor-saving environments. Indeed, there is now a wealth of data, both for humans and other animals, demonstrating that long-term lifestyle changes involving increases in exercise or other physical activities do not result in commensurate increases in daily energy expenditure (DEE). This is because humans and other animals exhibit a degree of energy compensation at the organismal level, ameliorating some of the increases in DEE that would occur from the increased activity by decreasing the energy expended on other biological processes. And energy compensation can be sizable, reaching many hundreds of calories in humans. But the processes that are downregulated in the long-term to achieve energy compensation are far from clear, particularly in humans-we do not know how energy compensation is achieved. My review here of the literature on relevant exercise intervention studies, for both humans and other species, indicates conflict regarding the role, if any, of basal metabolic rate (BMR) or low-level activity such as fidgeting play, particularly once changes in body composition are factored out. In situations where BMR and low-level activity are not major components of energy compensation, what then drives it? I discuss how changes in mitochondrial efficiency and changes in circadian fluctuations in BMR may contribute to our understanding of energy management. Currently unexplored, these mechanisms and others may provide important insights into the mystery of how energy compensation is achieved.

Increasing Fracture Risk Associates With Plasma Circulating MicroRNAs in Aging People's Sarcopenia

Aging generally coincides with a gradual decline in mass and strength of muscles and bone mineral density (BMD). Sarcopenia is closely linked to osteoporosis in the elderly, which can lead to abnormal gait, balance disorders, and dysfunctions, as well as increase in the risks of falls, fractures, weakness, and death. MicroRNAs (miRNAs, miRs) are a kind of short and non-coding RNA molecules but can regulate posttranscriptional protein expression. However, we have known little about their participation in age-associated osteoporosis and sarcopenia. The current study aims to confirm those miRNAs as biomarkers for age-related reduction in muscular atrophy associated with human blood fractures. In our study, 10 fracture-risk-related miRNAs (miR-637, miR-148a-3p, miR-125b-5p, miR-124-3p, miR-122-5p, miR-100-5p, miR-93-5p, miR-21-5p, miR-23a-3p, and miR-24-3p) were analyzed. For the initial screening, we determined the abundance of fracture-risk-associated miRNAs by RT-PCR most frequently detected in enrolled 93 elderly with sarcopenia and non-sarcopenia, respectively. Statistically, the relative expression levels of plasma miR-23a-3p, miR-93-5p, and miR-637 in the sarcopenia group were significantly lower than that in the non-sarcopenia group, while the levels of other miRNAs did not change significantly. Moreover, we showed that the levels of ASM/height², handgrip strength, and 4-m velocity in the sarcopenia group were significantly lower than in the non-sarcopenia group. Whereafter, we expanded the sample for further detection and analysis and revealed that the levels of plasma miR-23a-3p, miR-93-5p, and miR-637 in the sarcopenia group were significantly lower than that in the non-sarcopenia group, which is consistent with the initial screening experiment. From our analysis, changes in levels of plasma miR-93-5p and miR-637 were dramatically related to ASM/height². Furthermore, changes in miR-23a and miR-93-5p were significantly affected by ASM/height² in female individuals, with no significant correlations between miRNAs changes and these diagnostic indexes in male individuals after adjusting sex. The study showed that plasma miRNAs changed in an aging-related sarcopenia manner and were associated with increased fracture risk. In aging patients, plasma miR-23a-3p, miR-93-5p, and miR-637 have the potential as biomarkers of sarcopenia, which can affect the development of physiological dysfunction and may be also used in the fracture risk assessment of these patients.

Comparison of total and activity energy expenditure estimates from physical activity questionnaires and doubly labelled water: a systematic review and meta-analysis

Physical activity questionnaires (PAQ) could be suitable tools in free-living people for measures of physical activity, total and activity energy expenditure (TEE and AEE). This meta-analysis was performed to determine valid PAQ for estimating TEE and AEE using doubly labelled water (DLW). We identified data from relevant studies by searching Google Scholar, PubMed and Scopus databases. This revealed thirty-eight studies that had validated PAQ with DLW and reported the mean differences between PAQ and DLW measures of TEE (TEEDLW - TEEPAQ) and AEE (AEEDLW - AEEPAQ). We assessed seventy-eight PAQ consisting of fifty-nine PAQ that assessed TEE and thirty-five PAQ that examined AEE. There was no significant difference between TEEPAQ and TEEDLW with a weighted mean difference of -243·3 and a range of -841·4 to 354·6 kJ/d, and a significant weighted mean difference of AEEDLW - AEE PAQ 414·6 and a range of 78·7-750·5. To determine whether any PAQ was a valid tool for estimating TEE and AEE, we carried out a subgroup analysis by type of PAQ. Only Active-Q, administered in two seasons, and 3-d PA diaries were correlated with TEE by DLW at the population level; however, these two PAQ did not demonstrate an acceptable limit of agreement at individual level. For AEE, no PAQ was correlated with DLW either at the population or at the individual levels. Active-Q and 3-d PA diaries were identified as the only valid PAQ for TEE estimation. Further well-designed studies are needed to verify this result and identify additional valid PAQ.

Association between walking energetics and fragmented physical activity in mid-to-late life

BACKGROUND

Physical activity becomes increasingly fragmented with age, which may be an early marker of functional decline. Energetic cost of walking and energy capacity are also linked with functional decline, but their associations with activity fragmentation, and the potential modifying roles of total daily physical activity and age, remains unclear.

METHODS

493 participants (50-93 years) from the Baltimore Longitudinal Study of Aging underwent measures of: energetic cost of usual-paced overground walking (ml/kg/m), energy demand during slow walking (ml/kg/min) on a treadmill (0.67 m/s, 0% grade),m/s, 0% grade), and average peak walking energy expenditure (ml/kg/min) during a fast-paced 400-m walk. A ratio of slow walking to peak walking energy expenditure ("cost-to-capacity ratio") was calculated. Activity fragmentation was quantified as an active-to-sedentary transition probability (ASTP) using Actiheart accelerometer data. Linear regression models with ASTP as the dependent variable were used to test whether poorer energy cost and capacity were associated with higher ASTP and whether the associations differed by daily physical activity or age.

RESULTS

After adjusting for demographics, body composition, comorbidities and daily physical activity, every 10% higher cost-to-capacity ratio was associated with 0.4% greater ASTP (p=0.005). This association was primarily driven by the least active participants (pinteraction=0.023). Peak walking energy expenditure was only associated with ASTP among participants aged ≥70 years.

CONCLUSIONS

Higher cost-to-capacity ratio and lower energy capacity may manifest as more fragmented physical activity, especially among those less active or aged ≥70 years. Future studies should examine whether an increasing cost-to-capacity ratio or declining energy capacity predicts subsequent activity fragmentation.

Stretch-Shortening Cycle Potentiation and Resistance Training-Induced Changes in Walking Economy/Ease and Activity-Related Energy Expenditure in Older Women

ABSTRACT

Hunter, GR, Singh, H, Martins, C, Baranauskas, MN, and Carter, SJ. Stretch-shortening cycle potentiation and resistance training-induced changes in walking economy/ease and activity-related energy expenditure in older women. J Strength Cond Res 35(5): 1345-1349, 2021-Use of elastic energy to improve economy and ease of walking may be important for older adults. The purpose of this investigation was to determine whether baseline (i.e., untrained) stretch-shortening cycle potentiation (SSCP) was associated with potential changes in free-living activity-related energy expenditure (AEE) after supervised exercise training. Sedentary, postmenopausal women (n = 64) between 60 and 74 years of age were evaluated before and after 16 weeks of combined aerobic and resistance training. Assessments included: (a) body composition (dual-energy X-ray absorptiometry), (b) resting energy expenditure (indirect calorimetry), (c) submaximal and maximal walking (treadmill/indirect calorimetry), (d) total energy expenditure (doubly labeled water), and (e) one repetition maximum performed on an incline leg press and SSCP (calculated as the difference between concentric and countermovement leg press throw). Results indicated that baseline SSCP was related (r = -0.29; p < 0.02) to changes in AEE. However, subjects who possessed a high baseline SSCP did not increase SSCP or AEE, whereas subjects with low to moderate baseline SSCP demonstrated a significant increase in both SSCP (low +0.54 and moderate +0.47 m·s-1) and AEE (low +158 and moderate +333 kcal·d-1) post-training (all p less than 0.05). Our findings suggest that among subjects with low to moderate baseline SSCP, 16 weeks of combined aerobic and resistance training can increase SSCP and free-living AEE. However, subjects with high baseline SSCP may require tailored exercise to increase SSCP and possibly AEE.

Morning fatigue and structured exercise interact to affect non-exercise physical activity of fit and healthy older adults

Background

Exercise training is crucial for maintaining physical and mental health in aging populations. However, as people participate in structured exercise training, they tend to behaviorally compensate by decreasing their non-exercise physical activity, thus potentially blunting the benefits of the training program. Furthermore, physical activity of older adults is substantially influenced by physical feelings such as fatigue. Nevertheless, how older people react to day-to-day fluctuations of fatigue and whether fatigue plays a role in non-exercise physical activity compensation is not known. Thus, the purpose of this study was twofold: (1) To explore whether the volume and intensity of habitual physical activity in older adults were affected by morning fatigue. (2) To investigate the effect of attending power and resistance exercise sessions on the levels of non-exercise physical activity later that day and the following day.

Methods

Twenty-eight older adults wore an accelerometer during a 4-week low-volume, low-intensity resistance and power training program with three exercise sessions per week and for 3 weeks preceding and 1 week following the program. During the same period, the participants were prompted every morning, using text messages, to rate their momentary fatigue on a scale from 0 to 10.

Results

Greater morning fatigue was associated with lower volume (p = 0.002) and intensity (p = 0.017) of daily physical activity. Specifically, one point greater on the fatigue scale was associated with 3.2 min (SE 1.0) less moderate-to-vigorous physical activity. Furthermore, attending an exercise session was associated with less moderate-to-vigorous physical activity later that day by 3.7 min (SE 1.9, p = 0.049) compared to days without an exercise session. During the next day, the volume of physical activity was greater, but only in participants with a body mass index up to 23 (p = 0.008).

Conclusions

Following low-volume exercise sessions, fit and healthy older adults decreased their non-exercise physical activity later that day, but this compensation did not carry over into the next day. As momentary morning fatigue negatively affects daily physical activity, we suggest that the state level of fatigue should be monitored during intensive exercise programs, especially in less fit older adults with increased fatigability.

Examining Race-Related Error in Two-Compartment Models of Body Composition Assessment: A Systematic Review and Meta-Analysis

BACKGROUND

The Brozek and Siri formulas estimate relative adiposity (%Fat) from total body density (D_b) using a 2-compartment (2C) model. Racial/ethnic differences in D_b have been reported, along with subsequent errors in estimated %Fat.

OBJECTIVE

The primary aim of this systematic review and meta-analysis was to examine potential race/ethnic differences in the accuracy of the Brozek and Siri 2C formulas using aggregate-level data.

METHODS

Peer-reviewed studies available in English that provided 2C and 4C estimates of %Fat were located using searches of the PubMed (n = 150), Scopus (n = 170), and Web of Science (n = 138) online electronic databases. Random-effects models were used to determine potential differences between racial groups using a mean ES and 95% confidence intervals.

RESULTS

The cumulative results from 78 effects indicate that the relative accuracy of the Brozek equation did not vary between racial groups (between group p = 0.053). In contrast, the Siri equation slightly underestimated %Fat for Asian adults (ES_WMD = -1.40%, 95%CI -2.33% to -0.46%; p = 0.004) and Black adults (ES_WMD = -1.10%, 95%CI -2.11% to -0.08%; p = 0.034), with no significant differences observed in Hispanic adults (ES_WMD = 0.64%, 95%CI -1.02% to 2.31%; p = 0.448) and White adults (ES_WMD = 0.08%, 95%CI -0.42% to 0.57%; p = 0.766) (between group p = 0.019).

CONCLUSION

Small, but statistically significant, error was found between racial groups when estimating %Fat using the 2C Siri equation when compared to 4C models. However, the observed error due to race/ethnicity appears to be of little clinical or practical significance when using either equation.

Resistance Training Associated with Dietetic Advice Reduces Inflammatory Biomarkers in the Elderly

Aging is a biological process during which chronic low-grade inflammation is present due to changes in the immune system of the elderly. The main objective of this study is to evaluate the effects of resistance training associated with dietary advice on chronic inflammation in the elderly. We conducted a prospective intervention study in which we evaluated anthropometric parameters and inflammatory biomarkers (CRP, IL-8, CCL-2, and leptin) in 40 elderly people before and after long-term progressive resistance training (19 weeks) associated with dietary advice. The participants trained twice a week on nonconsecutive days, and the training lasted one hour with an intensity of 60-85% of 1-MR. Dietary advice was explained in person and individually focusing on foods rich in compounds with anti-inflammatory and antioxidant properties. Participants were instructed at the beginning of the training program, and dietary advice was reinforced verbally weekly. There was an improvement in body composition evidenced by a reduction in waist circumference and body fat percentage and by the increase in arm circumference, calf circumference, and corrected arm muscle area. In addition, there was a reduction in the inflammatory biomarkers CCL-2 (p = 0.01) and leptin (p < 0.01). Resistance training associated with dietary guidance can contribute to a healthy aging due to observed improvements in body composition and in the inflammatory profile of the elderly.

Strategies for Physical Activity Interventions in the Treatment of Obesity

Physical activity contributes to body weight regulation. At least 150 minutes per week of moderate-to-vigorous intensity physical activity may be needed. When not coupled with dietary restriction, physical activity contributes to an average weight loss of approximately 2 to 3 kg in interventions up to 6 months in duration; when added to modest dietary restriction it adds 20% additional weight loss compared with modest dietary restriction alone. Physical activity is associated with enhanced long-term weight loss and attenuation of weight regain and should be included within clinical and public health approaches to prevent weight regain and to treat obesity.

Ratings of Perceived Exertion During Walking Predicts Endurance Independent of Physiological Effort in Older Women

Hunter, GR, Neumeier, WH, Chandler-Laney, PC, Carter, SJ, Borges, JH, Hornbuckle, LM, Plaisance, EP, and Fisher, G. Ratings of perceived exertion during walking predicts endurance independent of physiological effort in older women. J Strength Cond Res 34(5): 1340-1344, 2020-This study aimed to determine whether ratings of perceived exertion (RPE) and physiological effort at different exercise intensities relate to exercise endurance. Ninety-eight sedentary women (older than 60 years) completed 3 submaximal locomotion tasks: (a) stair climbing, (b) flat walking at 2 mph, and (c) grade walking at 2 mph. Maximal treadmill endurance was measured at least 3 days before the submaximal tests. Oxygen uptake was measured during all tests, and RPE were collected for the submaximal tasks. Ratings of perceived exertion during moderate-intensity exercise (walking on the flat at 43% V[Combining Dot Above]O2max, partial R = -0.35, p < 0.01), but not higher intensity exercise (grade walk at 59% V[Combining Dot Above]O2max, p = 0.49, and stair climbing at 67% V[Combining Dot Above]O2max, p = 0.17), were related to endurance even after adjusting for aerobic capacity and physiological effort (composite of maximal heart rate, ventilation, and respiratory exchange ratio). However, physiological effort was significantly related to endurance for the higher intensity exercise (both grade walk and stair climbing partial R >-0.24, p < 0.02). Similar to previous findings that subjective ratings of fatigue at rest were related to RPE during low/moderate-intensity exercise, but not higher intensity exercise, these data further support Ekkekakis's dual-mode hypothesis that cognitive factors influence RPE during low/moderate-intensity exercise. A practical application is that the coach and personal trainer should know that physiological effort seems to play a greater role in influencing endurance than RPE as intensity of exercise increases.

Electromyographic activity in deadlift exercise and its variants. A systematic review

The main purpose of this review was to systematically analyze the literature concerning studies which have investigated muscle activation when performing the Deadlift exercise and its variants. This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Statement (PRISMA). Original studies from inception until March 2019 were sourced from four electronic databases including PubMed, OVID, Scopus and Web of Science. Inclusion criteria were as follows: (a) a cross-sectional or longitudinal study design; (b) evaluation of neuromuscular activation during Deadlift exercise or variants; (c) inclusion of healthy and trained participants, with no injury issues at least for six months before measurements; and (d) analyzed "sEMG amplitude", "muscle activation" or "muscular activity" with surface electromyography (sEMG) devices. Major findings indicate that the biceps femoris is the most studied muscle, followed by gluteus maximus, vastus lateralis and erector spinae. Erector spinae and quadriceps muscles reported greater activation than gluteus maximus and biceps femoris muscles during Deadlift exercise and its variants. However, the Romanian Deadlift is associated with lower activation for erector spinae than for biceps femoris and semitendinosus. Deadlift also showed greater activation of the quadriceps muscles than the gluteus maximus and hamstring muscles. In general, semitendinosus muscle activation predominates over that of biceps femoris within hamstring muscles complex. In conclusion 1) Biceps femoris is the most evaluated muscle, followed by gluteus maximus, vastus lateralis and erector spinae during Deadlift exercises; 2) Erector spinae and quadriceps muscles are more activated than gluteus maximus and biceps femoris muscles within Deadlift exercises; 3) Within the hamstring muscles complex, semitendinosus elicits slightly greater muscle activation than biceps femoris during Deadlift exercises; and 4) A unified criterion upon methodology is necessary in order to report reliable outcomes when using surface electromyography recordings.

Exercise-induced α-ketoglutaric acid stimulates muscle hypertrophy and fat loss through OXGR1-dependent adrenal activation

Beneficial effects of resistance exercise on metabolic health and particularly muscle hypertrophy and fat loss are well established, but the underlying chemical and physiological mechanisms are not fully understood. Here, we identified a myometabolite‐mediated metabolic pathway that is essential for the beneficial metabolic effects of resistance exercise in mice. We showed that substantial accumulation of the tricarboxylic acid cycle intermediate α‐ketoglutaric acid (AKG) is a metabolic signature of resistance exercise performance. Interestingly, human plasma AKG level is also negatively correlated with BMI. Pharmacological elevation of circulating AKG induces muscle hypertrophy, brown adipose tissue (BAT) thermogenesis, and white adipose tissue (WAT) lipolysis in vivo. We further found that AKG stimulates the adrenal release of adrenaline through 2‐oxoglutarate receptor 1 (OXGR1) expressed in adrenal glands. Finally, by using both loss‐of‐function and gain‐of‐function mouse models, we showed that OXGR1 is essential for AKG‐mediated exercise‐induced beneficial metabolic effects. These findings reveal an unappreciated mechanism for the salutary effects of resistance exercise, using AKG as a systemically derived molecule for adrenal stimulation of muscle hypertrophy and fat loss.

High Intensity Interval Training Does Not Have Compensatory Effects on Physical Activity Levels in Older Adults

Background: Exercise has beneficial effects on older adults, but controversy surrounds the purported “compensatory effects” that training may have on total daily physical activity and energy expenditure in the elderly. We wanted to determine whether 8 weeks of high-intensity interval training (HIIT) induced such effects on physical activity and energy expenditure in healthy, active older adult men. Methods: Twenty-four healthy elderly male volunteers were randomized to two groups. The experimental group performed HIIT (7 × 2 min cycling repetitions, 3 d/w); the control group performed continuous moderate-intensity training (20–30 min cycling, 3 d/w). Physical activity and energy expenditure were measured with a multisensor activity monitor SenseWear Armband Mini. Results: During HIIT, significant changes were observed in moderate and vigorous physical activity, average daily metabolic equivalents (METs), physical activity level, and activity energy expenditure (p < 0.05) but not in total energy expenditure. Sleep and sedentary time, and levels of light physical activity remained constant during the training period. Conclusions: The findings suggest that HIIT induced no compensatory effect: HIIT does not adversely affect lifestyle, as it does not reduce daily energy expenditure and/or increase sedentary time.

Resistance Training for Older Adults: Position Statement From the National Strength and Conditioning Association

Fragala, MS, Cadore, EL, Dorgo, S, Izquierdo, M, Kraemer, WJ, Peterson, MD, and Ryan, ED. Resistance training for older adults: position statement from the national strength and conditioning association. J Strength Cond Res 33(8): 2019-2052, 2019-Aging, even in the absence of chronic disease, is associated with a variety of biological changes that can contribute to decreases in skeletal muscle mass, strength, and function. Such losses decrease physiologic resilience and increase vulnerability to catastrophic events. As such, strategies for both prevention and treatment are necessary for the health and well-being of older adults. The purpose of this Position Statement is to provide an overview of the current and relevant literature and provide evidence-based recommendations for resistance training for older adults. As presented in this Position Statement, current research has demonstrated that countering muscle disuse through resistance training is a powerful intervention to combat the loss of muscle strength and muscle mass, physiological vulnerability, and their debilitating consequences on physical functioning, mobility, independence, chronic disease management, psychological well-being, quality of life, and healthy life expectancy. This Position Statement provides evidence to support recommendations for successful resistance training in older adults related to 4 parts: (a) program design variables, (b) physiological adaptations, (c) functional benefits, and (d) considerations for frailty, sarcopenia, and other chronic conditions. The goal of this Position Statement is to a) help foster a more unified and holistic approach to resistance training for older adults, b) promote the health and functional benefits of resistance training for older adults, and c) prevent or minimize fears and other barriers to implementation of resistance training programs for older adults.

Relationship between V̇o2peak, cycle economy, and mitochondrial respiration in untrained/trained

Aerobic capacity is negatively related to locomotion economy. The purpose of this paper is to determine what effect aerobic exercise training has on the relationship between net cycling oxygen uptake (inverse of economy) and aerobic capacity [peak oxygen uptake (V̇o_2peak)], as well as what role mitochondrial coupled and uncoupled respiration may play in whole body aerobic capacity and cycling economy. Cycling net oxygen uptake and V̇o_2peak were evaluated on 31 premenopausal women before exercise training (baseline) and after 8-16 wk of aerobic training. Muscle tissue was collected from 15 subjects at baseline and post-training. Mitochondrial respiration assays were performed using high-resolution respirometry. Pre- (r = 0.46, P < 0.01) and postexercise training (r = 0.62, P < 0.01) V̇o_2peak and cycling net oxygen uptake were related. In addition, uncoupled and coupled fat respiration were related both at baseline (r = 0.62, P < 0.01) and post-training (r = 0.89, P < 01). Post-training coupled (r = 0.74, P < 0.01) and uncoupled carbohydrate respiration (r = 0.52, P < 05) were related to cycle net oxygen uptake. In addition, correlations between V̇o_2peak and cycle net oxygen uptake persist both at baseline and after training, even after adjusting for submaximal cycle respiratory quotient (an index of fat oxidation). These results suggest that the negative relationship between locomotion economy and aerobic capacity is increased following exercise training. In addition, it is proposed that at least one of the primary factors influencing this relationship has its foundation within the mitochondria. Strong relationships between coupled and uncoupled respiration appear to be contributing factors for this relationship.NEW & NOTEWORTHY The negative relationship between cycle economy and aerobic capacity is increased following exercise training. The strong relationship between coupled and uncoupled respiration, especially after training, appears to be contributing to this negative relationship between aerobic capacity and cycling economy, suggesting that mitochondrial economy is not increased following aerobic exercise training. These results are suggestive that training programs designed to improve locomotion economy should focus on changing biomechanics.

Combined Aerobic and Resistance Training Increases Stretch- Shortening Cycle Potentiation and Walking Economy in Postmenopausal Women

Purpose

Secondary analyses were performed to test whether combined aerobic and resistance training altered walking economy (i.e., net oxygen uptake) and/or stretch-shortening cycle potentiation (SSCP). A further objective was to determine if walking economy and SSCP were related before or after training.

Methods

Ninety-two postmenopausal women were enrolled wherein 76 completed 16 weeks of supervised aerobic and resistance training. Participants were randomized to one of three training groups based on frequencies: (a) 1 d⋅wk^–1 (n = 23); (b) 2 d⋅wk^–1 (n = 30) or; (c) 3 d⋅wk^–1 (n = 23). Following assessments were performed at baseline and post-training. Indirect calorimetry was used to measure maximal oxygen uptake () and walking economy (submaximal – resting = net ) during a graded exercise test and steady-state treadmill task, respectively. SSCP was determined by measuring the difference between a concentric (CO) and counter-movement (CM) leg press throw.

Results

, walking economy, CO and CM velocity were significantly improved (p < 0.05) for all training groups, however; no time by group interactions were observed. Paired t-tests revealed participants exercise training 2 d⋅wk^–1 exhibited a significant time effect for SSCP (+0.04 ± 0.09 ms^–1; p = 0.03). At baseline, multiple linear regression showed a negative relationship between walking net and SSCP (r = −0.22; p < 0.04) adjusted for relative proportion of  . No such relationship was found post-training.

Conclusion

Among older postmenopausal women, our results indicate that irrespective of frequency of training, 16 weeks of combined aerobic and resistance exercise training increased ease of walking and economy. Additionally, only participants exercising 2 d⋅wk^–1 exhibited significant improvement in SSCP.

Comparisons of low-intensity versus moderate-intensity combined aerobic and resistance training on body composition, muscle strength, and functional performance in older women

OBJECTIVE

This study aimed to examine the effects of exercise order of combined aerobic and low- or moderate-intensity resistance training into the same session on body composition, functional performance, and muscle strength in healthy older women. Furthermore, this study compared the effects of different (low- vs moderate-) intensity combined training.

METHODS

A total of 60 healthy older women (age 61-81 y) were randomly assigned to five groups that performed aerobic exercise before low-intensity resistance training (AR-L, n = 12) or after resistance training (RA-L, n = 12), performed aerobic exercise before moderate-intensity resistance training (AR-M, n = 12) or after resistance training (RA-M, n = 12), or nonintervention control conditions (CON, n = 12). Body composition, functional performance, and muscle strength were evaluated before and after the 10-week training.

RESULTS

No effects of exercise order of combined aerobic and low- or moderate-intensity resistance training (AR-L vs RA-L, AR-M vs RA-M) were observed in body composition, functional performance, or muscle strength, whereas the effects of training intensity of combined training (AR-L vs AR-M, RA-L vs RA-M) were observed on functional performance. All combined trainings significantly increased muscle strength and gait ability (P < 0.01, respectively). Functional reach test significantly increased in the AR-M and RA-M groups (P < 0.01, respectively), and there were significant group differences between AR-L and AR-M (P = 0.002), RA-L and RA-M (P = 0.014).

CONCLUSIONS

Preliminary findings suggest that combined aerobic and low- or moderate-intensity resistance training increases muscle strength and improves gait ability, regardless of the exercise order. Also, greater improvement in dynamic balance capacity, a risk factor associated with falling, is observed in moderate-intensity combined training.

Effects of higher habitual protein intake on resistance-training-induced changes in body composition and muscular strength in untrained older women: A clinical trial study

BACKGROUND

Aging is accompanied by progressive and accentuated decline in muscular strength and skeletal muscle mass, affecting health and functional autonomy. Both resistance training (RT) and diet are strategies that may contribute to improvement in the health of the elderly.

AIM

The purpose of this study was to evaluate the effects of higher habitual protein intake on RT-induced changes in body composition and strength in untrained postmenopausal women.

METHODS

Seventy older women were submitted to an RT program. Body composition, muscular strength, and dietary intake (24 h dietary recall) were performed pre- and post-intervention. To verify different intervention effects according to protein intake of the participants, the sample was separated into tertiles according to protein intake: low, moderate, and high protein intake.

RESULTS

A time vs. group interaction ( p < 0.05) was observed, with high protein intake presenting greater increases compared with low protein intake, for skeletal muscle mass (5.3% vs. 1.3%), lower limb lean soft tissue (4.9% vs. 1.4%), upper lean soft tissue (4.9% vs. 1.2%), preacher curl (24% vs. 15.2%), and total strength (16.4% vs. 11.7%). A time vs. group interaction ( p < 0.05) was observed, with high protein intake presenting greater increases compared with moderate protein intake, for skeletal muscle mass (5.3% vs. 3.2%). In all groups, a main effect of time ( p < 0.05) was observed for knee extension and chest press.

CONCLUSIONS

We conclude that intake of >1.0 g/kg/day of protein promotes gains in skeletal muscle mass and muscular strength after RT in untrained older women.

The association of resistance training with mortality: A systematic review and meta-analysis

BACKGROUND

The benefits of aerobic exercise are well-studied; there is no consensus on the association between resistance training and major adverse cardiovascular outcomes. This systematic review and meta-analysis aimed to address this issue.

DESIGN AND METHODS

We searched for randomized trials and cohort studies that evaluated the association between resistance training and mortality and cardiovascular events. Two investigators screened the identified abstracts and full-texts independently and in duplicate. Cochrane tools were used to assess the risk of bias. We calculated hazard ratios and 95% confidence intervals using random effect models.

RESULTS

From the 1430 studies identified, 11 (one randomized trial and 10 cohort studies) met the inclusion criteria, totaling 370,256 participants with mean follow-up of 8.85 years. The meta-analysis showed that, compared with no exercise, resistance training was associated with 21% (hazard ratio (95% confidence interval (CI)), 0.79 (0.69-0.91)) and 40% (hazard ratio (95% CI), 0.60 (0.49-0.72)) lower all-cause mortality alone and when combined with aerobic exercise, respectively. Furthermore, resistance training had a borderline association with lower cardiovascular mortality (hazard ratio (95% CI), 0.83 (0.67-1.03)). In addition, resistance training showed no significant association with cancer mortality. Risk of bias was low to intermediate in the included studies. One cohort study looked at the effect of resistance training on coronary heart disease events in men and found a 23% risk reduction (risk ratio, 0.77, CI: 0.61-0.98).

CONCLUSION

Resistance training is associated with lower mortality and appears to have an additive effect when combined with aerobic exercise. There are insufficient data to determine the potential beneficial effect of resistance training on non-fatal events or the effect of substituting aerobic exercise with resistance training.

Sarcopenia and Its Implications for Metabolic Health

Sarcopenia not only affects the ability to lead an active lifestyle but also contributes to increased obesity, reduced quality of life, osteoporosis, and metabolic health, in part due to reduced locomotion economy and ease. On the other hand, increased obesity, decreased quality of life, and reduced metabolic health also contribute to sarcopenia. The purpose of this mini-review is to discuss the implications sarcopenia has for the development of obesity and comorbidities that occur with aging.

The Importance of Resistance Exercise Training to Combat Neuromuscular Aging

Older adults undergoing age-related decrements in muscle health can benefit substantially from resistance exercise training, a potent stimulus for whole muscle and myofiber hypertrophy, neuromuscular performance gains, and improved functional mobility. With the use of advancing technologies, research continues to elucidate the mechanisms of and heterogeneity in adaptations to resistance exercise training beyond differences in exercise prescription. This review highlights the current knowledge in these areas and emphasizes knowledge gaps that require future attention of the field.

Indirect calorimetry as point of care testing

Determining energy requirement is a fundamental of nutrition support. Indirect calorimetry (IC) has been long recognized as the gold standard for assessing basal or resting energy expenditure (REE). The measurement of REE is recommended particularly in the situation where adjustment of energy provision is critical. The result of the IC measurement can lead to changes in treatment and since the change can be carried out immediately at the bedside, this may be considered as point-of-care testing. Beyond the nutritional aspects, studies of energy expenditure with IC have brought out more understanding of the metabolic changes during the natural course of diseases or conditions as well as those related to the intervention. The literature in various disease states has shown that changes in energy expenditure may reveal hidden metabolic information that might be translated into clinical information and have the potential of being both prognostic indicators and/or treatment targets.

Age-associated changes of resting energy expenditure, body composition and fat distribution in Chinese Han males

Age-related alterations in whole body composition, particularly, reduced fat free mass (FFM) and increased fat mass (FM), lead to a progressive decline in resting energy expenditure (REE). Similarly, regional body composition and fat distribution changes with age might also contribute to an overall lower REE. This study investigated the influence of age on REE, regional body composition and fat distribution, including subcutaneous fat (SF) and visceral fat (VF), in a Chinese Han population as well as their contributions to age-related changes in REE. One hundred and two males aged 31-83 years old underwent dual-energy X-ray absorptiometry (DXA) which measured whole body and regional FM and FFM. SF and VF were measured by magnetic resonance imaging (MRI) and REE by indirect calorimetry. Age was significantly negatively correlated with REE (r = -0.37), total FFM (r = -0.25), upper limbs FFM (r = -0.32), lower limbs FFM (r = -0.34) and showed positive association with trunk FFM (β=0.926). FM, SF and VF decreased in older age groups after an initial rise up to 55-65 years. REE correlated positively to FM, FFM, SF, VF and showed significant association with age (β = -0.254) independent of age-associated changes in body composition. The regional alterations in body composition with age were explained by changes in trunk FFM (β = 0.926). Age-related decline in REE were not solely due to alterations in FM and FFM. Therefore, the changes in regional body composition, fat distribution and REE which occur during aging could be explained by disparities in race, ethnicity, diet, physical activity, and lower specific metabolic rates of FFM components.

May the force be with you: why resistance training is essential for subjects with type 2 diabetes mellitus without complications

Physical activity, together with diet and pharmacological therapy, represents one of the three cornerstones in type 2 diabetes mellitus treatment and care. The therapeutic appeal of regular physical activity stems from: (i) its non-pharmacological nature; (ii) its beneficial effects on the metabolic risk factors associated with diabetes complications; (iii) its low costs. Evidence accumulated in the last years suggests that aerobic training-endurance training-constitutes a safe modality of intervention, achievable, and effective in diabetes treatment, whenever it is not limited by comorbidities. Aerobic training exerts insulin-mimetic effects and has been shown to lower mortality risk too. Anaerobic, intense physical activity, such as that of strength or power sports disciplines, is not univocally recognized as safe and simple to realize, however, it is important in stimulating energy and glucose metabolism. According to recent evidence, high-intensity training may be prescribed even in the face of cardiovascular diseases, peripheral vascular disease, or osteoarthritis. Some studies have shown resistance training to be more efficient than aerobic exercise in improving glycemic control. This review explores the most up-to-date indications emerging from literature in support of the beneficial effects of strength stimulation and resistance training in patients with type 2 diabetes without complications.

Racial Differences in Relative Skeletal Muscle Mass Loss During Diet-Induced Weight Loss in Women

OBJECTIVE

It is unclear whether there are race-specific differences in the maintenance of skeletal muscle during energy restriction. Changes in relative skeletal muscle index (RSMI; limb lean tissue divided by height squared) were compared following (1) diet alone, (2) diet + aerobic training, or (3) diet + resistance training.

METHODS

Overweight, sedentary African American (AA; n = 72) and European American (EA; n = 68) women were provided an 800-kcal/d diet to reduce BMI < 25 kg/m² . Regional fat-free mass was measured with dual-energy x-ray absorptiometry. Steady-state VO₂ and heart rate responses during walking were measured.

RESULTS

AA women had greater RSMI and preserved RSMI during diet alone, while RSMI was significantly reduced among EA women (EA women -3.6% vs. AA women + 1.1%; P < 0.05). Diet + resistance training subjects retained RSMI (EA women + 0.2% vs. AA women + 1.4%; P = 50.05), whereas diet + aerobic training subjects decreased RSMI (EA women -1.4% vs. AA women -1.5%; P < 0.05). Maintenance of RSMI was related to delta walking ease and economy.

CONCLUSIONS

Compared with AA women, EA women are less muscular and lose more muscle during weight loss without resistance training. During diet-induced weight loss, resistance training preserves skeletal muscle, especially among premenopausal EA women. Maintenance of muscle during weight loss associates with better ease and economy of walking.

Effects of Strength Training on Muscle Properties, Physical Function, and Physical Activity among Frail Older People: A Pilot Study

The aim of this study was to determine the effects of a 10-week strength training intervention on isometric strength, rate of force development (RFD), physical function (stair climbing, rising from a chair, and preferred and maximal walking speed), and physical activity among frail elderly people receiving home-care services. Thirty participants were randomly assigned (by sex) to a control group (CON) or a strength training group (ST) performing a supervised training programme using elastic bands, box-lifting, and body weight exercises twice per week. Twenty-three participants were selected to complete the study (age 84.9 ± 6.1 years). For the ST, only improvement in muscle properties was the peak RFD in leg extension (p=0.04). No significant differences were observed in muscle properties for the control group (CON) (p=0.16–1.00) or between groups (p=0.39–1.00). There were no changes within and between the groups in physical function (p=0.12–0.19) or physical activity levels (p=0.06–0.73). The results of this pilot study did not demonstrate greater improvements in muscle properties and physical function and improved physical activity after attending a home-based resistance program compared to physical activity advise; however, larger population studies should examine these findings. This trial is registered with ISRCTN10967873.

Bidirectional association between physical activity and muscular strength in older adults: Results from the UK Biobank study

Background: The relationship between physical activity and muscular strength has not been examined in detail among older adults. The objective of this study was to examine the associations between physical activity and hand grip strength among adults aged ≥ 60 years.

Methods: Using data from the UK Biobank study, we included 66 582 men and women with complete baseline data and 6599 with 4.5 years of follow-up data. We used multiple linear regression models to examine the cross-sectional, longitudinal and bidirectional associations between moderate-to-vigorous physical activity (MVPA) and grip strength, adjusting for potential confounding by age, sex, height, weight, health status, education level, smoking status, Townsend deprivation index and retirement status.

Results: In cross-sectional analyses, grip strength and MVPA were linearly and positively associated with each other. Longitudinally, baseline MVPA was not associated with grip strength at follow-up {difference between quintile [Q] 5 and Q1 = 0.40 [95% confidence interval (CI): -0.14, 0.94]kg}, whereas baseline grip strength was associated with MVPA at follow-up [Q5 vs Q1 = 7.15 (1.18, 13.12) min/day]. People who maintained/increased time spent in MVPA did not experience any benefit in grip strength [0.08 (−0.20, 0.37) kg] whereas those who increased their grip strength spent 3.69 (0.20, 7.17) min/day extra in MVPA.

Conclusion: Promotion of strength-training activities may enable and maintain participation in regular physical activity among older adults.

Resistance training reduces metabolic syndrome and inflammatory markers in older women: A randomized controlled trial

BACKGROUND

This study analyzed the effects of a 12-week resistance training (RT) program without dietary interventions on metabolic syndrome (MetS) components and inflammatory biomarkers in older women.

METHODS

Fifty-three older women (mean [±SD] age 70.4 ± 5.7 years; mean body mass index 26.7 ± 4.0 kg/m² ) were randomly assigned to a training group (TG; n = 26) that performed 12 weeks of an RT program or a control group (CG; n = 27) that did not perform any type of physical exercise over the same period. Body composition (dual energy X-ray absorptiometry), muscular strength (one-repetition maximum tests), blood pressure (BP), and blood sample measurements were performed before and after intervention.

RESULTS

After the 12-week period, there were significantly reductions (P < 0.05) in glucose levels (-20.4% vs -0.3%), waist circumference (-1.5% vs +2.0%), and systolic BP (-6.2% vs +0.9%), and complete normalization of MetS prevalence (18% at baseline vs. 0% after 12-weeks RT) in the TG. Moreover, C-reactive protein and tumor necrosis factor-α concentrations decreased in the TG (-28.6% and -21.6%, respectively), but increased in the CG (+34.5% and +13.3%, respectively). In addition there were positive improvements in the MetS Z-score in the TG but not CG (-21.6% vs +13.3%, respectively).

CONCLUSION

The results suggest that a 12-week RT program seems to effectively reduce MetS components and inflammatory biomarkers in older women, regardless of dietary intervention. The RT-induced adaptations in body composition and inflammatory biomarkers appear to be related to healthy adaptations in risk factors for MetS.

Why intensity is not a bad word: Optimizing health status at any age

Age-related declines in health and function make locomotion increasingly difficult leading to reductions in non-exercise activity thermogenesis (NEAT), skeletal muscle size and strength, and increased adiposity. Exercise is an important strategy to attenuate loss of function through the life cycle. Despite claims to the contrary, high-intensity exercise is important for the prevention of obesity and sarcopenia with advancing age. Therefore, the purpose of this mini-review is to present literature supporting the contention that low volume, high-intensity aerobic and/or resistance training can slow sarcopenia, sustain ease of movement, stimulate NEAT, and attenuate the accretion of fat mass.

Influence of previous body mass index and sex on regional fat changes in a weight loss intervention

OBJECTIVES

Men and women may lose weight in a different fashion. This study compares the changes in different anatomical regions after a well-controlled weight loss program by sex and initial BMI.

METHODS

A total of 180 subjects (48 overweight women, 36 overweight men, and 48 obese women and 48 obese men) were recruited to participate in a 22-week weight loss programme (diet + exercise).

RESULTS

Regarding percentage body weight change from baseline, there was no triple interaction (BMI, sex and anatomical region), but there was interaction between BMI and anatomical region (F2,840 = 34.5; p < 0.001), and between sex and anatomical region (F2,840 = 98.8; p < 0.001). Usually, the arms and legs are the regions that lose more weight in obese participants, but men lose the highest percentage of mass from the trunk. There were differences between men and women for the areas of left trunk mass (750g), right trunk mass (700g), total mass of the trunk (1400g), android mass (350g), and finally in the total mass in overweight participants (1300g), with higher values for men than for women. The region that loses more weight and fat is the trunk, followed by the legs, and then the arms, when the loss is observed in function of the total weight or fat lost.

CONCLUSION

Both BMI and sex exert a definite influence fat loss, especially in some anatomical regions.

Exercise, energy expenditure and energy balance, as measured with doubly labelled water

The doubly labelled water method for the measurement of total daily energy expenditure (TDEE) over 1–3 weeks under daily living conditions is the indicated method to study effects of exercise and extreme environments on energy balance. Subjects consume a measured amount of doubly labelled water (2H218O) to increase background enrichment of body water for 18O and 2H, and the subsequent difference in elimination rate between 18O and 2H, as measured in urine, saliva or blood samples, is a measure for carbon dioxide production and thus allows calculation of TDEE. The present review describes research showing that physical activity level (PAL), calculated as TDEE (assessed with doubly labelled water) divided by resting energy expenditure (REE, PAL = TDEE/REE), reaches a maximum value of 2·00–2·40 in subjects with a vigorously active lifestyle. Higher PAL values, while maintaining energy balance, are observed in professional athletes consuming additional energy dense foods to compete at top level. Exercise training can increase TDEE/REE in young adults to a value of 2·00–2·40, when energy intake is unrestricted. Furthermore, the review shows an exercise induced increase in activity energy expenditure can be compensated by a reduction in REE and by a reduction in non-exercise physical activity, especially at a negative energy balance. Additionally, in untrained subjects, an exercise-induced increase in activity energy expenditure is compensated by a training-induced increase in exercise efficiency.

Adiposity and grip strength as long-term predictors of objectively measured physical activity in 93 015 adults: the UK Biobank study

Background/Objectives:

Fatness and fitness are associated with physical activity (PA) but less is known about the prospective associations of adiposity and muscle strength with PA. This study aimed to determine longitudinal associations of body mass index (BMI), waist circumference (WC) and grip strength (GS) with objectively measured PA.

Subjects/Methods:

Data are from the UK Biobank study. At baseline (2006–2010), BMI, WC and GS were objectively measured. At follow-up (2013–2015), a sub-sample of 93 015 participants (52 161 women) wore a tri-axial accelerometer on the dominant wrist for 7 days. Linear regression was performed to investigate longitudinal associations of standardised BMI, WC and GS at baseline with moderate-to-vigorous PA (MVPA) and acceleration after a median 5.7-years follow-up (interquartile range: 4.9–6.5 years).

Results:

Linear regression revealed strong inverse associations for BMI and WC, and positive associations for GS with follow-up PA; in women, MVPA ranges from lowest to highest quintiles of GS were 42–48 min day⁻¹ in severely obese (BMI⩾35 kg m⁻²), 52–57 min day⁻¹ in obese (30⩽BMI<35 kg m⁻²), 61–65 min day⁻¹ in overweight (25⩽BMI<30 kg m⁻²) and 69–75 min day⁻¹ in normal weight (18.5⩽BMI<25 kg m⁻²). Follow-up MVPA was also lower in the lowest GS quintile (42–69 min day⁻¹) compared with the highest GS quintile (48–75 min day⁻¹) across BMI categories in women. The pattern of these associations was generally consistent for men, and in analyses using WC and mean acceleration as exposure and outcome, respectively.

Conclusions:

More pronounced obesity and poor strength at baseline independently predict lower activity levels at follow-up. Interventions and policies should aim to improve body composition and muscle strength to promote active living.

Obesity and Physical Activity

Some clinical manifestations of obesity include nonalcoholic fatty liver disease, type 2 diabetes, and cardiovascular disease. Calorie restriction may aid in weight loss in the short term. Exercise and physical activity are other means of weight loss. However, the efficacy of exercise and physical activity in weight reduction in obese populations is still unknown. In this review, we discuss the effects of exercise and physical activity in obese and overweight populations. We also discuss the effects of aerobic exercise and/or resistance training in weight loss and maintenance.

The effect of exercise on non-exercise physical activity and sedentary behavior in adults

It is widely assumed that structured exercise causes an additive increase in physical activity energy expenditure (PAEE) and total daily energy expenditure (TDEE). However, the common observation that exercise often leads to a less than expected decrease in body weight, without changes in energy intake, suggests that some compensatory behavioral adaptations occur. A small number of human studies have shown that adoption of structured exercise can lead to decreases in PAEE, which is often interpreted as a decrease in physical activity (PA) behavior. An even smaller number of studies have objectively measured PA, and with inconsistent results. In animals, high levels of imposed PA induce compensatory changes in some components of TDEE. Recent human cohort studies also provide evidence that in those at the highest levels of PA, TDEE is similar when compared to less physically active groups. The objective of this review is to summarize the effects of structured exercise training on PA, sedentary behavior, PAEE and TDEE. Using models from ecological studies in animals and observational data in humans, an alternative model of TDEE in humans is proposed. This model may serve as a framework to investigate the complex and dynamic regulation of human energy budgets.

Obesity and energy balance: What is the role of physical activity?

Despite billions of dollars spent over decades of research, debate remains over the causes and solutions of the obesity epidemic. The specific role of physical activity in the prevention or treatment of obesity seems a particularly contentious issue, with opposing views put forth in both academic and popular media. In an attempt to provide context and clarity to the specific question of the role of physical activity in determination of body weight, we have attempted to identify evidence or lack thereof in the scientific literature and provide a summary of our findings. Areas covered: Topics included in this narrative review are an overview of energy balance, the relationship between physical activity and energy expenditure, compensatory responses in non-exercise energy expenditure and energy intake, and the relationship between physical activity and obesity. Expert commentary: Based on a review of the existing literature, daily physical activity and structured exercise has beneficial effects on an individual's body weight. In most instances, exercise occurring in adequate amounts will increase total daily energy expenditure and create an acute energy deficit, without compensatory decreases in non-exercise physical activity or energy expenditure nor compensatory increases in energy intake. Several gaps in the literature exist, both in terms of the number of adequately powered clinical trials with rigorous assessments of both energy intake and expenditure, and with a variety of study populations (by age, sex, race, etc.) and with varying exercise volumes and intensities.

Influence of Relative Strength on Functional Independence of Patients With Spinal Cord Injury

OBJECTIVE

To investigate the influence of strength values and fat mass on functional independence of men with different spinal cord injury (SCI) levels.

DESIGN

Cross-sectional study.

SETTING

Hospital network.

PARTICIPANTS

Men with SCI (N=45).

INTERVENTIONS

Subjects were assessed in functional independence scales, a 1 repetition maximum (1RM) test, and body composition to detect absolute and relative strength: 1RM divided by body mass (BM) and lean body mass (LBM), respectively.

MAIN OUTCOME MEASURES

Stepwise multiple regression analysis was used to verify the influence of predictors on functional independence (FIM and Spinal Cord Independence Measure [SCIM] scale and subscales). Receiver operating characteristic curves were created to identify cutoff points of strength for functional independence.

RESULTS

The best models for FIM total, FIM mobility, and SCIM total used 1RM as the best predictor (adjusted R²=.75, .67, and .65, respectively; P<.05). Relative strength (1RM/LBM) was the best predictor for SCIM mobility (adjusted R²=.62, P<.05). A FIM score of 69 has a 1RM cutoff point of 50.1kg, and a FIM score of 76 has cutoff points of .73 for 1RM/BM and .91 for 1RM/LBM. A SCIM score of 68 has cutoff points for 1RM, 1RM/BM, and 1RM/LBM of 50.1kg, .77, and .92, respectively.

CONCLUSIONS

Cutoff points of relative strength should be used as determinant variables for independence, health, or sports performance. This study may contribute to more adequate guidance of physical activity during a rehabilitation program and after discharge.