Effects of Different Resistance Training Frequencies on Fat in Overweight/Obese Older 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.

Different resistance training volumes on strength, functional fitness, and body composition of older people: A systematic review with meta-analysis

Aging causes several changes in the body, reducing strength and muscle mass, which leads to a decline in function. Resistance training (RT) is used to counteract these changes. However, there is still ongoing debate about the optimal volume of RT in the context of aging. We systematically reviewed articles that assessed the impact of different volumes of RT on muscular strength, functional fitness, and body composition of older people. We conducted a systematic search in the PubMed/MEDLINE, Scopus, Embase, Web of Science, Cochrane Library, LILACS, PEDro, and Google Scholar databases, using keywords related to the older population and various RT volumes. We performed meta-analyses for each outcome separately using intervention time in weeks for subgroup analyses. We employed random effects models for all meta-analyses and expressed the results as standardized mean differences (Hedges' g). We included 31 studies, encompassing a total of 1.744 participants. The sample size ranged from 18 to 376, with an average size of 56 participants. Participants' ages ranged from 60 to 83 years. On average, HV-RT (High-Volume Resistance Training) induced significant adaptations in muscle strength of the upper limbs (g = 0.36; 95 % CI = 0.11-0.61) and lower limbs (g = 0.41; 95 % CI = 0.23-0.59), with superiority more pronounced after 12 weeks of training. Regarding functional fitness, there was a tendency favoring HV-RT (g = 0.41; 95 % CI = 0.23-0.59). Thus, HV-RT outperforms LV-RT (Low-Volume Resistance Training) in enhancing muscle strength, particularly in longer interventions with independent older adults.

Effect of resistance training volume on body adiposity, metabolic risk, and inflammation in postmenopausal and older females: Systematic review and meta-analysis of randomized controlled trials

PURPOSE

This meta-analytical study aimed to explore the effects of resistance training (RT) volume on body adiposity, metabolic risk, and inflammation in postmenopausal and older females.

METHODS

A systematic search was performed for randomized controlled trials in PubMed, Scopus, Web of Science, and SciELO. Randomized controlled trials with postmenopausal and older females that compared RT effects on body adiposity, metabolic risk, and inflammation with a control group (CG) were included. Independent reviewers selected the studies, extracted the data, and performed the risk of bias and certainty of the evidence (Grading of Recommendations, Assessment, Development, and Evaluation (GRADE)) evaluations. Total body and abdominal adiposity, blood lipids, glucose, and C-reactive protein were included for meta-analysis. A random-effects model, standardized mean difference (Hedges' g), and 95% confidence interval (95%CI) were used for meta-analysis.

RESULTS

Twenty randomized controlled trials (overall risk of bias: some concerns; GRADE: low to very low) with overweight/obese postmenopausal and older females were included. RT groups were divided into low-volume RT (LVRT, ∼44 sets/week) and high-volume RT (HVRT, ∼77 sets/week). Both RT groups presented improved body adiposity, metabolic risk, and inflammation when compared to CG. However, HVRT demonstrated higher effect sizes than LVRT for glucose (HVRT = -1.19; 95%CI: -1.63 to -0.74; LVRT = -0.78; 95%CI:-1.15 to -0.41) and C-reactive protein (HVRT = -1.00; 95%CI: -1.32 to -0.67; LVRT = -0.34; 95%CI, -0.63 to -0.04)) when compared to CG.

CONCLUSION

Compared to CG, HVRT protocols elicit greater improvements in metabolic risk and inflammation outcomes than LVRT in overweight/obese postmenopausal and older females.

Resistance Training and Weight Loss in Older Adults: A Scoping Review

Resistance training (RT) is one of the most effective interventions available to older adults wishing to slow the progressive loss of muscle size and strength known to occur with age. Less is known about the ability of RT to resist the onset of an equally problematic condition related to increased age: obesity. The objective of this scoping review was to characterize current research associated with RT and weight loss in older adults, including protocols, feasibility, and gaps in current knowledge. We searched six databases using variations of the terms "resistance training," "weight loss," and "older adults" for experimental or quasi-experimental studies published in the year 2009 or later. Studies were included if they featured at least one treatment group with a mean age of > 65 years that engaged in an RT-only exercise protocol with no aerobic or high-intensity interval component. Of the 6102 references identified by the initial database search, 24 were retained for analysis. Older women and older adults with obesity or sarcopenic obesity were the most studied groups (n = 13), followed by healthy community-dwelling older adults (n = 11) and studies involving older adults and some aspect of either dietary control or pharmaceutical intervention (n = 8). Significant between-study heterogeneity was observed in the RT characteristics researchers thought optimal for improving body composition measures in older adults. Changes in body composition, rather than total body mass, were found to be the essential variables to consider when evaluating the effectiveness of an RT intervention aimed at reducing chronic disease in older adults. Weight loss alone appears to be an incomplete and problematic outcome measure for older adults, with changes in body composition (ratio of fat mass to lean mass) being the more appropriate variable to emphasize in this population. However, it is important to note that only one study, showing questionably reproducible findings, found a significant lean body mass gain. The lack of abundant high-quality evidence demonstrating combined RT and a healthy diet can lead to significant fat loss and lean body mass gain, coupled with high attrition rates observed in many of the studies reviewed, highlight the need for further rigorous research.

Research hotspots and new trends in the impact of resistance training on aging, bibliometric and visual analysis based on CiteSpace and VOSviewer

Purpose

Resistance training (RT) can intervene in aging, which can effectively improve trainees' life. However, unhealthy living habits such as irregular life, obesity and hyperlipidemia, and chronic diseases lead to a significant decline in the energy level of the population, seriously affecting the health of the population. Our research identifies the research hotspots of RT to intervene in aging from the perspective of bibliometrics, predicts research frontiers and development trends, and provides more perspectives for research on aging populations.

Methods

In this study, we used CiteSpace and VOSviewer visualization software to draw the scientific knowledge map of countries/regions, institutions, authors, co-occurrence keywords, and co-cited references of published articles, and explore the Web of Science core collection database all about the RT intervention aging research status, hotspots, frontiers, and development trends of articles on aging.

Results

Among the 760 articles that meet the inclusion criteria, the number of articles published and the frequency of citations have increased steadily in the past 5 years. Judging from the countries/regions, institutions, scholars, and journals that published articles, the ones with the largest numbers are the USA, Univ Estadual Londrina, Cyrino ES, and Exp Gerontol. The ones with the highest influence are England, Univ Arkansas Med Sci, Frontera WR, and Biochem Biophys Rep Co. The top five co-occurrence keywords of include exercise, strength, resistance training, skeletal muscle, and muscle strength. The research frontier is physical function.

Conclusion

In the field of RT intervention aging research, relevant scholars deserve further in-depth research and exploration. The United States, Brazil, Canada, and other economically developed countries/regions, institutions, and authors have greater influence and productivity. These quantitative research results can provide references for relevant scholars' follow-up research and government departments to formulate and modify health policies or measures.

Nutrition and exercise interventions to improve body composition for persons with overweight or obesity near retirement age: A systematic review and network meta-analysis of randomised controlled trials

The retirement phase is an opportunity to integrate healthy (nutrition/exercise) habits into daily life. We conducted this systematic review to assess which nutrition and exercise interventions most effectively improve body composition (fat/muscle mass), body mass index (BMI) and waist circumference (WC) in persons with obesity/overweight near retirement age (ages 55-70). We conducted a systematic review and network-meta-analysis (NMA) of randomised controlled trials, searching four databases from their inception up to 12 July 2022. The NMA was based on a random effects model, pooled mean differences, standardised mean differences, their 95% confidence intervals, and correlations with multi-arm studies. Subgroup and sensitivity analyses were also conducted. 92 studies were included, 66 of which with 4957 participants could be used for the NMA. Identified interventions were clustered into 12 groups: no intervention, energy restriction (i.e. 500-1000 kcal), energy restriction plus high protein (HP) intake (1.1-1.7 g/kg/body weight), intermittent fasting, mixed exercise (aerobic and resistance), resistance training (RT), aerobic training (AT), HP plus RT, energy restriction plus HP plus exercise, energy restriction plus RT, energy restriction plus AT, and energy restriction plus mixed exercise (ME). Intervention durations ranged from 8 weeks to 6 months. Body fat was reduced with energy restriction plus any exercise or plus HP intake. Energy restriction alone was less effective and tended to decrease muscle mass. Muscle mass was only significantly increased with ME. All other interventions including exercise effectively preserved muscle mass. A BMI and/or WC decrease was achieved with all interventions except AT/RT alone or RT plus HP. Overall, the most effective strategy for nearly all outcomes was combining energy restriction with RT or ME and HP. Healthcare professionals involved in the management of persons with obesity need to be aware that an energy-restricted diet alone may contribute to sarcopenic obesity in persons near retirement age. This network meta-analysis is registered at https://www.crd.york.ac.uk/prospero/as CRD42021276465.

Effects of resistance training on body weight and body composition in older adults: An inter-individual response difference meta-analysis of randomized controlled trials

Whether true inter-individual response differences (IIRD) occur as a result of resistance training on body weight and body composition in older adults with overweight and obesity is not known. To address this gap, data from a previous meta-analysis representing 587 men and women (333 resistance training, 254 control) ≥ 60 years of age nested in 15 randomized controlled trials of resistance training ≥ 8 weeks were included. Resistance training and control group change outcome standard deviations treated as point estimates for body weight and body composition (percent body fat, fat mass, body mass index in kg.m2, and lean body mass) were used to calculate true IIRD from each study. True IIRD as well as traditional pairwise comparisons were pooled using the inverse-variance (IVhet) model. Both 95% confidence intervals (CI) and prediction intervals (PI) were calculated. While statistically significant improvements were found for body weight and all body composition outcomes (p < 0.05 for all), no statistically significant IIRD was observed for any of the outcomes (p > 0.05 for all) and all 95% PIs overlapped. Conclusions: While resistance training is associated with improvements in body weight and body composition in older adults, the lack of true IIRD suggests that factors other than training response variation (random variation, physiological responses associated with behavioral changes that are not the result of resistance training) are responsible for the observed variation in body weight and body composition.

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.

Effect of Resistance Exercise Order on Cardiovascular Disease Risk Factors in Older Women: A Randomized Controlled Trial

We compared the effects of two specific resistance training (RT) exercise orders on cardiovascular risk factors. Forty-four untrained older women (>60 years) were randomly assigned to three groups: control (CON, n = 15), multi-joint to single-joint (MJ-SJ, n = 14), and single-joint to multi-joint (SJ-MJ, n = 15) exercise orders. Training groups performed a whole-body RT program (eight exercises, 3 × 10−15 repetitions for each exercise) over 12 weeks in 3 days/week. Body fat, triglycerides, total cholesterol, HDL-c, LDL-c, VLDL-c, glucose, IL-6, IL-10, TNF-α, C-reactive protein, total radical-trapping antioxidant (TRAP), advanced oxidation protein products (AOPP), ferrous oxidation-xylenol (FOX), and nitric oxide concentrations (NOx) were determined pre- and post-intervention. Significant interaction group × time (p < 0.05) revealed reducing fat mass and trunk fat and improvements in glucose, LDL-c, IL-10, TNF-α, C-reactive protein, FOX, and AOPP concentrations in both training groups, without differences between them (p > 0.05). The results suggest that 12 weeks of RT, regardless of exercise order, elicit positive adaptations on body fat and metabolic biomarkers similarly in older women.

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.

Comparison of 2 Weekly Frequencies of Resistance Training on Muscular Strength, Body Composition, and Metabolic Biomarkers in Resistance-Trained Older Women: Effects of Detraining and Retraining

ABSTRACT

Amarante do Nascimento, M, Nunes, JPA, Pina, FLC, Ribeiro, AS, Carneiro, NH, Venturini, D, Barbosa, DS, Mayhew, JL, and Cyrino, ES. Comparison of 2 weekly frequencies of resistance training on muscular strength, body composition, and metabolic biomarkers in resistance-trained older women: Effects of detraining and retraining. J Strength Cond Res 36(5): 1437-1444, 2022-This study aimed to compare the effects of 2 weekly frequencies of resistance training (RT) on muscular strength, body composition, and metabolic biomarkers in previously resistance-trained older women after detraining and retraining. Forty subjects (>60 years) performed RT (8 exercises, 1 set of 10-15 repetitions maximum) 2 (G2x) or 3 (G3x) times per week over 12 weeks of training and retraining. After training, subjects were detrained for 12 weeks. After detraining, there were significant decreases (p < 0.05) in upper-body (∼12%) and lower-body (∼14%) muscular strength, fat-free mass (FFM) (∼2%), and testosterone (∼26%), whereas increases were revealed for fat mass (FM) (∼4%), relative body fat (∼3%), fasting glucose (∼8%), low-density lipoprotein cholesterol (LDL-C) (∼21%), and triglycerides (∼24%), with no differences between groups (p > 0.05). Following retraining, there were significant increases (p < 0.05) for upper (∼7%) and lower (∼10%) muscular strength, FFM (∼2%), and testosterone (∼20%). In contrast, decreases were found for FM (∼7%), relative body fat (∼3%), fasting glucose (∼6%), LDL-C (∼14%), and triglycerides (∼21%), also with no differences between groups (p > 0.05). Gains after retraining were lower than after training (p < 0.05) only for upper- and lower-body muscular strength (∼6%) and testosterone (∼11%). Total cholesterol, high-density lipoprotein cholesterol, IGF-1, and C-reactive protein did not change at any point in the study for either group (p > 0.05). Our results suggest that older women can regain previous RT program benefits following detraining, regardless of the weekly training frequency. However, some fitness components may take longer to reestablish than the initial training level.

The Effect of Resistance Training in Healthy Adults on Body Fat Percentage, Fat Mass and Visceral Fat: A Systematic Review and Meta-Analysis

BACKGROUND

Resistance training is the gold standard exercise mode for accrual of lean muscle mass, but the isolated effect of resistance training on body fat is unknown.

OBJECTIVES

This systematic review and meta-analysis evaluated resistance training for body composition outcomes in healthy adults. Our primary outcome was body fat percentage; secondary outcomes were body fat mass and visceral fat.

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

We searched five electronic databases up to January 2021.

ELIGIBILITY CRITERIA

We included randomised trials that compared full-body resistance training for at least 4 weeks to no-exercise control in healthy adults.

ANALYSIS

We assessed study quality with the TESTEX tool and conducted a random-effects meta-analysis, with a subgroup analysis based on measurement type (scan or non-scan) and sex (male or female), and a meta-regression for volume of resistance training and training components.

RESULTS

From 11,981 records, we included 58 studies in the review, with 54 providing data for a meta-analysis. Mean study quality was 9/15 (range 6-15). Compared to the control, resistance training reduced body fat percentage by - 1.46% (95% confidence interval - 1.78 to - 1.14, p < 0.0001), body fat mass by - 0.55 kg (95% confidence interval - 0.75 to - 0.34, p < 0.0001) and visceral fat by a standardised mean difference of - 0.49 (95% confidence interval - 0.87 to - 0.11, p = 0.0114). Measurement type was a significant moderator in body fat percentage and body fat mass, but sex was not. Training volume and training components were not associated with effect size. Resistance training reduces body fat percentage, body fat mass and visceral fat in healthy adults.

STUDY REGISTRATION

osf.io/hsk32.

The impact of resistance training on body composition, muscle strength, and functional fitness in older women (45-80 years): A systematic review (2010-2020)

As women age, they typically experience a progressive decrease in skeletal muscle mass and strength, which can lead to a decline in functional fitness and quality of life. Resistance training (RT) has the potential to attenuate these losses. Although well established for men, evidence regarding the benefits of RT for women is sparse and inconsistent: prior reviews include too few studies with women and do not adequately examine the interactive or additive impacts of workload, modalities, and nutritional supplements on outcomes such as muscle mass (MM), body composition (BC), muscle strength (MS), and functional fitness (FF). The purpose of this review is to identify these gaps. Thirty-eight papers published between 2010 and 2020 (in English) represent 2519 subjects (mean age = 66.89 ± 4.91 years). Intervention averages include 2 to 3 × 50 min sessions across 15 weeks with 7 exercises per session and 11 repetitions per set. Twelve studies (32%) examined the impact of RT plus dietary manipulation. MM, MS, and FF showed positive changes after RT. Adding RT to fitness regimens for peri- to postmenopausal women is likely to have positive benefits.

Characteristics of Physical Exercise Programs for Older Adults in Latin America: A Systematic Review of Randomized Controlled Trials

AIM

To characterize physical exercise programs for older adults in Latin America.

METHODS

This review was conducted in accordance with the PRISMA statement. A search for randomized controlled trials (RCTs) published between the years 2015 and 2020 was performed in the Scopus, MedLine and SciELO databases.

RESULTS

A total of 101 RCTs were included. A large percentage of the studies had an unclear risk of bias in the items: selection, performance, detection and attribution. Furthermore, a heterogeneous level of compliance was observed in the CERT items. A total sample of 5013 older adults (79% women) was included. 97% of the studies included older adults between 60-70 years, presenting an adherence to the interventions of 86%. The studies were mainly carried out in older adults with cardiometabolic diseases. Only 44% of the studies detailed information regarding the place of intervention; of these studies, 61% developed their interventions in university facilities. The interventions were mainly based on therapeutic physical exercise (89% of the articles), with a duration of 2-6 months (95% of the articles) and a frequency of 2-3 times a week (95% of the articles) with sessions of 30-60 min (94% of the articles) led by sports science professionals (51% of the articles). The components of physical fitness that were exercised the most were muscular strength (77% of the articles) and cardiorespiratory fitness (47% of the articles). Furthermore, only 48% of the studies included a warm-up stage and 34% of the studies included a cool-down stage.

CONCLUSIONS

This systematic review characterized the physical exercise programs in older adults in Latin America, as well the most frequently used outcome measures and instruments, by summarizing available evidence derived from RCTs. The results will be useful for prescribing future physical exercise programs in older adults.

Effects of Pyramid Resistance-Training System with Different Repetition Zones on Cardiovascular Risk Factors in Older Women: A Randomized Controlled Trial

This study analyzed the effects of the pyramidal resistance training (RT) system with two repetition zones on cardiovascular risk factors in older women (≥60 years old). Fifty-nine older women were randomly assigned in three groups: non-exercise control (CON, n = 19), narrow-pyramid system (NPR, n = 20), and wide-pyramid system (WPR, n = 20). Training was performed for eight weeks (eight exercises for the whole-body, 3x/week) in which NPR and WPR performed three sets of 12/10/8 and 15/10/5 repetitions, respectively. Regional body fat was estimated by dual-energy X-ray absorptiometry, and blood parameters related to glycemic, lipid, and inflammatory profiles were assessed. After the training period, although no difference was observed for the magnitude of the changes between NPR and WPR, significant group by time interactions indicated benefits with RT compared to CON for reducing body fat (mainly android body fat; −7%) and improving glucose, HDL-C, LDL-C and C-reactive protein (p < 0.05). Composite z-score of cardiovascular risk, created by the average of the intervention effects on the outcomes, indicate similar responses between NPR and WPR, differing from CON (p < 0.001). Results indicate that both the repetition zones of the pyramidal RT reduced similarly the cardiovascular risk in older women.

Effects of Different Resistance Training Frequencies on Body Composition, Cardiometabolic Risk Factors, and Handgrip Strength in Overweight and Obese Women: A Randomized Controlled Trial

BACKGROUND

Resistance training improves health in obese and overweight people. However, it is not clear what is the optimal weekly resistance training frequency and the most efficacious training protocol on body composition, cardiometabolic risk factors, and handgrip strength (HS). The aim of this study was to determine the effects of a supervised structured 24 week resistance training program on obese and overweight women.

METHODS

Forty-five women (BMI 37.1 ± 6.3 kg/m²; age 56.5 ± 0.7 years) were randomly assigned to one of two groups: A group with a high weekly training frequency of three times a week (HIGH) and a group that performed it only once a week (LOW). Cardiometabolic risk factors, anthropometric and HS measures were taken before and after the intervention period.

RESULTS

A significant (p < 0.05) group by time interaction was observed for body weight, body mass index, waist circumference, fat mass, plasma glucose, plasma insulin, homeostatic model assessment, and for dominant and absolute HS. Additionally, only the HIGH group saw increased HS and decreased total cholesterol and LDL-cholesterol after the intervention period (p < 0.05). The observed increase in HS was associated with an improved insulin resistance sensitivity (absolute handgrip strength: r = -0.40, p = 0.007; relative handgrip strength: r = -0.47, p = 0.001) after training, which constitutes an essential element for cardiovascular health.

CONCLUSIONS

The results suggest that high weekly frequency training give greater benefits for weight loss and cardiometabolic risk factors improvement than a training program with a training session of once a week. Furthermore, the improvement of HS can be achieved with a high weekly frequency 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 effect of resistance training on health-related quality of life in older adults: Systematic review and meta-analysis

Background: Resistance training (RT) is recommended as part of our national physical activity guidelines which includes working all major muscle groups on two or more days a week.Older adults can gain many health benefits from RT, such as increased muscle strength,increased muscle mass, and maintenance of bone density. Additionally, certain dimensions of health-related quality of life (HRQOL) have been shown to improve in older adults due to RT intervention. The purpose of this study was to use systematic review and meta-analytic techniques to examine the effect of RT on HRQOL in older adults.

Methods: A systematic review of current studies (2008 thru 2017) was conducted using PubMed. Studies were included if they used a randomized controlled design, had RT as an intervention, measured HRQOL using the SF-36/12 assessment, and included adults 50+ years of age. Eight dimension scores (physical functioning, bodily pain, physical role function, general health, mental health, emotional role function, social function, and vitality) and two summary scores (physical component and mental component) were extracted. Ten meta-analyses were performed using standardized mean effect sizes and random effects models. Study quality,moderator and sensitivity analyses were conducted.

Results: A total of 16 studies were included in the analyses with a mean Physiotherapy Evidence Database (PEDro) score of 4.9 (SD=1.0). Among the mental health measures, RT had the greatest effect on mental health (Effect size [ES]=0.64, 95% CI: 0.30-0.99, I²=79.7). Among the physical health measures, RT had the largest effect on body pain (ES=0.81, 95% CI: 0.26-1.35, I²=85.9).Initially, RT did not significantly affect measures of emotional role function, social function or physical role function. However, after removing a single study, RT significantly increased all HRQOL measures.

Conclusion: The meta-analytic evidence presented in this research clearly supports the promotion of RT in improving HRQOL in older adults.

How many times per week should a muscle be trained to maximize muscle hypertrophy? A systematic review and meta-analysis of studies examining the effects of resistance training frequency

Training frequency is considered an important variable in the hypertrophic response to regimented resistance exercise. The purpose of this paper was to conduct a systematic review and meta-analysis of experimental studies designed to investigate the effects of weekly training frequency on hypertrophic adaptations. Following a systematic search of PubMed/MEDLINE, Scoups, and SPORTDiscus databases, a total of 25 studies were deemed to meet inclusion criteria. Results showed no significant difference between higher and lower frequency on a volume-equated basis. Moreover, no significant differences were seen between frequencies of training across all categories when taking into account direct measures of growth, in those considered resistance-trained, and when segmenting into training for the upper body and lower body. Meta-regression analysis of non-volume-equated studies showed a significant effect favoring higher frequencies, although the overall difference in magnitude of effect between frequencies of 1 and 3+ days per week was modest. In conclusion, there is strong evidence that resistance training frequency does not significantly or meaningfully impact muscle hypertrophy when volume is equated. Thus, for a given training volume, individuals can choose a weekly frequency per muscle groups based on personal preference.