Weight training, aerobic physical activities, and long-term waist circumference change in men

Ostarine blunts the effect of endurance training on submaximal endurance in rats

The purpose of this study is to study the effects of ostarine alone and in combination with endurance training in sexually mature, male Wistar rats. The rats were divided into a treadmill-trained group and a sedentary group. Half of each group received either ostarine or vehicle for 8 weeks (n = 10 each, in total n = 40). We examined some functional, hormonal, and anthropometric parameters and the myogenic gene expression of myostatin, insulin-like growth factor-1 (IGF-1), and vascular endothelial growth factor-A (VEGF-A) in m. gastrocnemius. Ostarine decreased submaximal endurance and increased myogenic gene expression of myostatin but had no effect on maximal time to exhaustion and grip strength. Training increased submaximal endurance, maximal time to exhaustion, and grip strength. Our results indicate that both exercise and ostarine treatment had no significant effects on serum levels of luteinizing hormone, follicle-stimulating hormone, and testosterone, or on the myogenic gene expression of IGF-1 and VEGF-A. Neither ostarine nor the training had a significant effect on the testis, liver, and heart weights. In conclusion, ostarine had no effect on anthropometric and hormonal parameters but increased the myostatin gene expression in muscle. The SARM treatment decreased submaximal endurance without affecting maximal time to exhaustion, and training increased both metrics.

Time-restricted feeding combined with resistance exercise prevents obesity and improves lipid metabolism in the liver of mice fed a high-fat diet

Nonalcoholic fatty liver disease (NAFLD), a condition characterized by the accumulation of fat in the liver, is estimated to be the most common liver disease worldwide. Obesity is a major risk factor and contributor, and, accordingly, weight loss can improve NAFLD. Previous studies in preclinical models of diet-induced obesity and fatty liver disease have shown the independent benefits of resistance exercise training (RT) and time-restricted feeding (TRF) in preventing weight gain and hepatic build-up of fat. Here, we tested the combined effect of TRF and RT on obesity and NAFLD in mice fed a high-fat diet. Our results showed that both TRF-8-h food access in the active phase-and RT-consisting of three weekly sessions of ladder climbing-attenuated body weight gain, improved glycemic homeostasis, and decreased the accumulation of lipids in the liver. TRF combined with RT improved the respiratory exchange rate, energy expenditure, and mitochondrial respiration in the liver. Furthermore, gene expression analysis in the liver revealed lower mRNA expression of lipogenesis and inflammation genes along with increased mRNA of fatty acid oxidation genes in the TRF + RT group. Importantly, combined TRF + RT was shown to be more efficient in preventing obesity and metabolic disorders. In conclusion, TRF and RT exert complementary actions compared with isolated interventions, with significant effects on metabolic disorders and NAFLD in mice.NEW & NOTEWORTHY Whether time-restricted feeding (TRF) combined with resistance exercise training (RT) may be more efficient compared with these interventions alone is still unclear. We show that when combined with RT, TRF provided additional benefits, being more effective in increasing energy expenditure, preventing weight gain, and regulating glycemic homeostasis than each intervention alone. Thus, our results demonstrate that TRF and RT have complementary actions on some synergistic pathways that prevented obesity and hepatic liver accumulation.

Dose-dependent associations of joint aerobic and muscle-strengthening exercise with obesity: A cross-sectional study of 280,605 adults

BACKGROUND

Emerging epidemiological evidence suggests that compared to engaging in 1 activity mode alone, a combination of moderate-to-vigorous physical activity (MVPA: brisk walking/jogging, cycling) and muscle-strengthening exercise (MSE: push-ups/sit-ups, using weight machines) has more favorable associations with optimal weight status. However, few studies have examined the dose-dependent and joint associations of MVPA and MSE with obesity.

METHODS

Based on cross-sectional analyses of the European Health Interview Survey Wave 2 (2013-2014), we examined prevalence ratios (PRs) of joint and stratified associations between MVPA (4 categories: (i) 0 min/week, (ii) 1-149 min/week, (iii) 150-299 min/week, and (iv) ≥300 min/week) and MSE (3 categories: (i) 0 day/week, (ii) 1 day/week, and (iii) ≥2 days/week) with body mass index-defined obesity (body mass index of ≥30.0 kg/m²) using Poisson regression with robust error variance. PRs were examined unadjusted and adjusted for sociodemographic and lifestyle characteristics (e.g., sex, age, education, income, and smoking status).

RESULTS

Data were available for 280,456 adults (≥18 years), of which 46,166 (15.5%) were obese. The interaction MVPA × MSE guideline adherence was statistically significant for obesity (p ≤ 0.05). The joint MVPA-MSE analysis showed that compared to the reference group (i.e., no MVPA and no MSE), the PRs followed a dose-dependent pattern, with the lowest observed among those reporting ≥150 MVPA min/week and ≥1 MSE days/week (PR: 0.43; 95% confidence interval: 0.41-0.46). When stratified across each MVPA strata, the PRs were mostly lower among those engaging in MSE 1 day/week, as compared to those doing MSE ≥2 days/week.

CONCLUSION

There was evidence for a dose-dependent association between joint MVPA-MSE with a reduced prevalence of obesity. Public health strategies for the prevention and management of obesity should recommend both MVPA and MSE.

Long-term Weight Training and Mortality in U.S. Male Health Professionals With and Without Type 2 Diabetes

OBJECTIVE

To investigate the relationship between long-term weight training and mortality in male health professionals with and without type 2 diabetes.

RESEARCH DESIGN AND METHODS

We analyzed 31,140 men without type 2 diabetes and 2,588 with type 2 diabetes from the Health Professionals Follow-up Study (1992-2018). Information on weight training was repeatedly assessed using a biennial questionnaire. Cox regression was used to estimate hazard ratios (HRs) and 95% CIs.

RESULTS

During up to 26 years of follow-up, we documented 12,607 deaths (988 deaths among men with type 2 diabetes). Among participants without type 2 diabetes, 1-59 and 60-149 min/week of long-term weight training were associated with 14% (HR 0.86; 95% CI 0.82-0.89) and 8% (HR 0.92; 95% CI 0.85-0.99) lower mortality versus no weight training, respectively, after adjustment for aerobic activity. However, ≥150 min/week of weight training was not significantly associated with mortality (HR 1.05; 95% CI 0.91-1.20; overall P trend = 0.94; P quadratic < 0.001). Meeting the recommended aerobic physical activity guideline (≥150 min/week) and performing any weight training were associated with 20-34% lower mortality. Among participants with type 2 diabetes, a moderate level of pre-diagnosis weight training was associated with lower mortality, whereas post-diagnosis weight training showed no association. Performing both weight training and aerobic activity before and after diagnosis was associated with lower mortality.

CONCLUSIONS

A moderate level of long-term weight training was associated with lower mortality, independently of aerobic activity, among male health professionals with and without type 2 diabetes. Addition of weight training to aerobic activities may provide further benefit in mortality risk reduction. Studies are required to confirm our findings in diverse populations.

RESISTANCE EXERCISE ATTENUATES IKKε PHOSPHORYLATION AND HEPATIC FAT ACCUMULATION OF OBESE MICE

Obesity is associated with low-grade inflammation and disturbances in hepatic metabolism. This study aimed to investigate the effects of resistance exercise on inflammatory signaling related to IKKepsilon protein (IKKɛ) and on hepatic fat accumulation in obese mice. Male Swiss mice were distributed into three groups: control (CTL) fed with standard chow; obese (OB) mice induced by a high-fat diet (HFD); obese exercised (OB+RE) mice fed with HFD and submitted to a resistance exercise training. The resistance exercise training protocol consisted of 20 sets/3 ladder climbs for eight weeks, three times/week on alternate days. The training overload was equivalent to 70% of the maximum load supported by the rodent. Assays were performed to evaluate weight gain, hepatic fat content, fasting glucose, insulin sensitivity, IKKɛ phosphorylation, and proteins related to insulin signaling and lipogenesis in the liver. Mice that received the high-fat diet showed greater adiposity, impaired insulin sensitivity, increased fasting glucose, and increased hepatic fat accumulation. These results were accompanied by an increase in IKKɛ phosphorylation and lipogenesis-related proteins such as cluster of differentiation 36 (CD36) and fatty acid synthase (FAS) in the liver of obese mice. In contrast, exercised mice showed lower body weight and adiposity evolution throughout the experiment. In addition, resistance exercise suppressed the effects of the high-fat diet by reducing IKKɛ phosphorylation and hepatic fat content. In conclusion, resistance exercise training improves hepatic fat metabolism and glycemic homeostasis, which are, at least in part, linked to the antiinflammatory effect of reduced IKKɛ phosphorylation in the liver of obese mice. This article is protected by copyright. All rights reserved.

Muscle-Strengthening Exercise Questionnaire (MSEQ): an assessment of concurrent validity and test–retest reliability

Objectives

Muscle-strengthening exercise (MSE) has multiple independent health benefits and is a component of global physical activity guidelines. However, the assessment of MSE in health surveillance is often limited to the constructs of frequency (days/week), with little focus on constructs such as MSE type, muscle groups targeted and intensity. This study describes the test–retest reliability and concurrent validity of the Muscle-Strengthening Exercise Questionnaire (MSEQ), which was developed to assess multiple MSE participation constructs.

Methods

The MSEQ was developed to assess the weekly frequency, session duration and intensity, types of MSE (eg, weight machines, bodyweight exercise) and muscle groups targeted. Two convenience samples of adult participants were recruited. Test–retest reliability was completed online by 85 participants. Concurrent validity was assessed for 54 participants using an online 7-day MSE log.

Results

The MSEQ shows high test–retest reliability for frequency, duration and level of intensity for each of the four MSE types (using weight machines, bodyweight exercises, resistance exercises and holistic exercises), and for the four types combined (ρ range 0.76–0.91). For muscle groups targeted, the reliability ranged mostly from moderate-to-substantial for each of the four MSE types (κ range 0.44–0.78) and fair-to-moderate for the four types combined (κ range 0.35–0.51). Concurrent validity for frequency, duration and level of intensity for each of the four MSE types, and the four types combined, was moderate-to-high (ρ range 0.30–0.77).

Conclusion

The MSEQ shows acceptable reliability and validity for four key MSE constructs. This new MSEQ survey instrument could be used to assess adults’ MSE.

Behavioral and Cognitive Outcomes of an Online Weight Loss Program for Men With Low Mood: A Randomized Controlled Trial

BACKGROUND

Depression and obesity are major health concerns and commonly co-exist, but men rarely seek help for these conditions. SHED-IT: Recharge was a gender-tailored eHealth program for men that generated clinically meaningful improvements in weight and depressive symptoms.

PURPOSE

To evaluate behavioral and psychological outcomes from the SHED-IT: Recharge intervention designed for overweight/obese men with low mood.

METHODS

Overall, 125 men (18-70 years) with a BMI between 25 and 42 kg/m2 and depressive symptoms (PHQ-9 ≥ 5) were randomly allocated to SHED-IT: Recharge (n = 62) or wait-list control (n = 63) groups. The self-directed program targeted key health behaviors combined with online mental fitness modules based on cognitive behavioral therapy. Behavioral (e.g., physical activity) and psychological outcomes (e.g., cognitive flexibility) were assessed with validated measures at baseline, 3 months (post-test) and 6 months (follow-up). Intention-to-treat linear mixed models examined treatment effects, which were adjusted for covariates, and effect size estimated (Cohen's d).

RESULTS

At post-test, intervention men achieved small-to-medium improvements in several health behavior outcomes including moderate-to-vigorous physical activity, light physical activity, sedentary behavior, sleep, energy intake, portion size, and risky alcohol consumption (range, d = 0.3-0.5), when compared with the control group. Intervention effects were also observed for perceived physical self-worth, perceived physical strength, cognitive flexibility, and behavioral activation (range, d = 0.3-0.8). No effects were found for fruit and vegetable intake, or mindful attention. Most effects were maintained at follow-up.

CONCLUSIONS

This gender-tailored, eHealth program with integrated mental fitness support elicited meaningful improvements in health behaviors and psychological outcomes for men with low mood. Trial Registration: Australian New Zealand Clinical Trials Registry (ACTRN12619001209189).

Muscle-strengthening activities and risk of cardiovascular disease, type 2 diabetes, cancer and mortality: A review of prospective cohort studies

The benefits of aerobic moderate-to-vigorous physical activity (MVPA) on major non-communicable diseases (NCDs) are well established. However, much less is known whether muscle-strengthening activities (i.e., resistance/weight/strength training) confer similar benefits. Herein, we conducted a narrative literature review and summarized the existing evidence from large prospective cohort studies on muscle strengthening activities and risk of major chronic diseases and mortality in adults generally free of major NCDs at baseline. Current epidemiologic evidence suggests that engagement in muscle-strengthening activities over 1-2 sessions (or approximately 60-150 min) per week was associated with reduced risk of cardiovascular disease (seven studies; approximately 20%-25% reduction), type 2 diabetes (four studies; approximately 30% reduction), cancer mortality (four studies; approximately 15%-20% reduction) as well as all-cause mortality (six studies; approximately 20%-25% reduction). For diabetes, the risk appears to lower further with even higher levels of muscle-strengthening activities, but some studies for cardiovascular and all-cause mortality suggest a reversal whereby higher levels (≥2.5 h/week) have less benefit, or are even harmful, relative to lower levels of activity. The likely mechanisms contributing to a benefit include improvement in body composition, lipid profile, insulin resistance and inflammation. The evidence supports engaging in 1-2 sessions (up to 2.5 h) per week, preferably performed complementary to the recommended levels of aerobic MVPA. Although data are limited, caution is suggested for training exceeding 2.5 h per week. Further studies are required to better understand the influence of frequency, duration and intensity of muscle-strengthening activities on major NCDs and mortality in diverse populations.

Changes over time in the relationship between weight, body fat, motivation, impulsivity and eating behaviour

BACKGROUND

University students are at a greater risk of gaining weight compared to others. We explored associations between changes in weight and a set of dispositional constructs related to eating behaviour: motivation, impulsivity, social comparison, and eating styles. We predicted that increases in controlled motivation, impulsivity, uncontrolled eating, emotional eating, and physical appearance comparison would be related to increased weight and body fat.

METHODS

First year students at a British university completed baseline (n = 196) and three-month (n = 163) measures of impulsivity, physical appearance comparison, motivation for following a healthy diet, eating styles, weight and body fat. Baseline-follow-up changes in these constructs were computed and subjected to cluster analysis.

RESULTS

Four participant groups were identified according to similarities in the way these constructs evolved over time. The Losing and Gaining groups tended to show opposing changes in key variables (physical appearance comparison, uncontrolled eating, motivation, weight, and percentage of body fat). Interestingly, two groups showed no change in weight and body fat but evidenced unique changes in key variables, indicating that individuals can have different psychological profiles but still maintain their weight.

CONCLUSIONS

The study highlighted how stable weight maintenance arises from sets of interdependent constructs rather than variables in isolation, as well as emphasizing a need to take a person-centred approach to examining those at risk of weight gain and in developing interventions.

Assessment of muscle-strengthening exercise in public health surveillance for adults: A systematic review

There is strong scientific evidence that muscle-strengthening exercise (i.e. use of weight machines, push-ups, sit-ups) is independently associated with a reduced risk of multiple chronic diseases (e.g. diabetes, hypertension, cardiovascular disease). However, prevalence rates for meeting the muscle-strengthening exercise guideline (≥2 times/week) are significantly lower (~20%) than those reported to meet the aerobic physical activity guideline (e.g. walking, jogging, cycling) (~50%). It is therefore important to understand public health surveillance approaches to assess muscle-strengthening exercise. The aim of this review was to describe muscle-strengthening exercise assessment in public health surveillance. Informed by the PRISMA guidelines, an extensive keyword search was undertaken across 7 electronic data bases. We identified 86,672 possible articles and following screening (n = 1140 in full-text) against specific inclusion criteria (adults aged ≥18 years, English, studies containing <1000 participants), extracted data from 156 manuscripts. Fifty-eight different survey systems were identified across 17 countries. Muscle-strengthening exercise frequency (85.3%), duration (23.7%) and intensity (1.3%) were recorded. Muscle-strengthening exercise questions varied significantly, with some (11.5%) requiring a singular 'yes' vs 'no' response, while others (7.7%) sought specific details (e.g. muscle groups targeted). Assessments of duration and intensity were inconsistent. Very few studies measured the validity (0.6%) and reliability (1.3%) of muscle-strengthening exercise questions. Discrepancy exists within the current assessment systems/surveys used to assess muscle-strengthening exercise in public health surveillance. This is likely to impede efforts to identify at risk groups and trends within physical activity surveillance, and to accurately assess associations between muscle-strengthening exercise and health-related outcomes.

Resistance exercise, alone and in combination with aerobic exercise, and obesity in Dallas, Texas, US: A prospective cohort study

BACKGROUND

Obesity is a significant and growing public health problem in high-income countries. Little is known about the relationship between resistance exercise (RE), alone and in combination with aerobic exercise (AE), and the risk of developing obesity. The purpose of this prospective cohort study was to examine the associations between different amounts and frequencies of RE, independent of AE, and incident obesity.

METHODS AND FINDINGS

Participants were 11,938 healthy adults ages 18-89 years with a BMI < 30 kg/m2 at baseline who completed at least 2 clinical examinations during 1987-2005 as part of the Aerobics Center Longitudinal Study. Self-reported RE participation in minutes/week and days/week was collected from a standardized questionnaire. Incident obesity was defined as a BMI ≥ 30 kg/m2 at follow-up. Incident obesity was also defined by waist circumference (WC) > 102/88 cm for men/women and percent body fat (PBF) ≥ 25%/30% for men/women at follow-up in participants who were not obese by WC (n = 9,490) or PBF (n = 8,733) at baseline. During the average 6-year follow-up, 874 (7%), 726 (8%), and 1,683 (19%) developed obesity defined by BMI, WC, or PBF, respectively. Compared with no RE, 60-119 min/wk of RE was associated with 30%, 41%, and 31% reduced risk of obesity defined by BMI (hazard ratio [95% CI], 0.70 [0.54-0.92], p = 0.008), WC (0.59 [0.44-0.81], p < 0.001), and PBF (0.69 [0.57-0.83], p < 0.001), respectively, after adjusting for confounders including age, sex, examination year, smoking status, heavy alcohol consumption, hypertension, hypercholesterolemia, diabetes, and AE. Compared with not meeting the RE guidelines of ≥2 d/wk, meeting the RE guidelines was associated with 18%, 30%, and 30% reduced risk of obesity defined by BMI (hazard ratio [95% CI], 0.82 [0.69-0.97], p = 0.02), WC (0.70 [0.57-0.85], p < 0.001), and PBF (0.70 [0.62-0.79], p < 0.001), respectively. Compared with meeting neither guideline, meeting both the AE and RE guidelines was associated with the smallest hazard ratios for obesity. Limitations of this study include limited generalizability as participants were predominantly white men from middle to upper socioeconomic strata, use of self-reported RE, and lack of detailed diet data for the majority of participants.

CONCLUSIONS

In this study, we observed that RE was associated with a significantly reduced risk of obesity even after considering AE. However, meeting both the RE and AE guidelines was associated with the lowest risk of obesity.

Reliability and Validity of Self-reported Muscle-strengthening Exercise in the Cancer Prevention Study-3

PURPOSE

This study examined the 1-yr reliability and construct validity of survey items relating to time spent on muscle-strengthening exercise (MSE) in a subset of a large prospective cohort.

METHODS

Participants (n = 293 men, 433 women; age, 32-73 yr) were selected from the Cancer Prevention Study-3. Information was collected using a 1-yr presurvey and postsurvey and four 7-d diaries throughout the year. The presurvey and postsurveys collected time spent on MSE in two ways: one question captured MSE activities performed during a typical 24-h period (24-h survey), and another question captured leisure-time physical activities performed in hours per week and months per year (LTPA survey). Time spent on MSE using the LTPA survey was calculated for individual MSE items and summed for total MSE time. One-year reliability was assessed by comparing the responses between the presurvey and postsurvey using Spearman's correlation coefficients. Construct validity was assessed by computing Spearman's correlation coefficients between responses from the postsurvey items and the diary. Additional analyses were conducted to examine whether reliability or validity varied by sociodemographic factors.

RESULTS

Reliability estimates for all MSE items were moderate (≥0.40) or strong (≥0.60) overall and across demographic strata. Reliability estimates were strongest for total MSE on the LTPA survey (Spearman ρ = 0.75; 95% confidence interval (CI), 0.71-0.78) compared with the 24-h survey (0.59; 95% CI, 0.54-0.64). In contrast, the validity estimates were similarly strong for the total MSE on the LTPA survey (Spearman ρ = 0.71; 95% CI, 0.67-0.75) and the 24-h survey (Spearman ρ = 0.68; 95% CI, 0.64-0.72).

CONCLUSIONS

The CPS-3 surveys have acceptable 1-yr reliability and validity for self-reported time spent on MSE. Reliability and validity estimates are acceptable across all sociodemographic subgroups.

The Influence of Specific Bioactive Collagen Peptides on Body Composition and Muscle Strength in Middle-Aged, Untrained Men: A Randomized Controlled Trial

It has been shown that specific collagen peptides combined with resistance training (RT) improves body composition and muscle strength in elderly sarcopenic men. The main purpose of this RCT study was to investigate the efficacy of the identical specific collagen peptides combined with RT on body composition and muscle strength in middle-aged, untrained men. Furthermore, in the exploratory part of the study, these results were compared with another group that had received whey protein in addition to the RT. Ninety-seven men completed this study and participated in a 12-week RT program. They ingested 15 g of specific collagen peptides (n = 30; CP-G), placebo (n = 31; P-G), or whey protein (n = 36; WP-G) daily. Changes in fat free mass and fat mass were determined by dual-energy X-ray absorptiometry (DXA), and isometric leg strength was measured. All participants had significantly (p < 0.01) improved levels in fat free mass (ΔCP-G = 3.42 ± 2.54 kg; ΔP-G = 1.83 ± 2.09 kg; ΔWP-G = 2.27 ± 2.56 kg), fat mass (ΔCP-G = -5.28 ± 3.19 kg; ΔP-G = -3.39 ± 3.13 kg; ΔWP-G = -4.08 ± 2.80 kg) and leg strength (ΔCP-G = 163 ± 189 N; ΔP-G = 100 ± 154 N; ΔWP-G = 120 ± 233 N). The main analysis revealed a statistically significantly higher increase in fat free mass (p = 0.010) and decrease in fat mass (p = 0.023) in the CP-G compared with the P-G. The exploratory analysis showed no statistically significant differences between WP-G and CP-G or P-G, regarding changes of fat free mass and fat mass. In conclusion, specific collagen peptide supplementation combined with RT was associated with a significantly greater increase in fat free mass and a decrease in fat mass compared with placebo. RT combined with whey protein also had a positive impact on body composition, but the respective effects were more pronounced following the specific collagen peptide administration.

The fit-active profile to better reflect the benefits of a lifelong vigorous physical activity participation: mini-review of literature and population data

Physical activity is favourably considered for its effect on metabolic fitness and body composition. This observation is generally supported by observational studies and is concordant with endurance-trained individuals' metabolic and morphological profiles. However, in some contexts, the measurement of physical activity habits may not provide an adequate representation of its benefits. In this paper, we review relevant literature on the respective effects of fitness and physical activity on anthropometric and metabolic variables and the informative potential of a classification based on aerobic fitness and activity indicators. The relevance to defining a profile based on both fitness and activity is reinforced by data from the Quebec Family Study showing that, in both men and women, "fit-active" individuals displayed a much more favourable morphological and metabolic profile than "unfit-inactive" individuals. Moreover, these benefits seemed to be more related to variations in fitness than in physical activity. In summary, evidence suggests that a profile combining information on aerobic fitness and physical activity may better reflect the lifelong impact of physical activity on body composition and health. Novelty: The fit-active profile better reflects the long-term benefits of vigorous physical activity participation on health. The reported benefits seem to be more related to variations in aerobic fitness than to those in physical activity.

Association of meeting both muscle strengthening and aerobic exercise guidelines with prevalent overweight and obesity classes - results from a nationally representative sample of German adults

OBJECTIVES

German national physical activity guidelines specify adults (≥18 years) should engage in at least: (i) 150 min of aerobic moderate-to-vigorous-intensity physical activity/week (MVPA); and (ii) muscle-strengthening exercise (MSE) 2 days/week. However, the relationship between MVPA and MSE and overweight/obesity has not been examined among German adults. Aim of this study was to examine whether meeting the guidelines for both MVPA and MSE is associated with a lower prevalence of overweight/obesity compared to meeting MVPA or MSE alone or none of them, among a nationally representative sample of German adults.

METHODS

The cross-sectional study drew data from the 2014 German Health Update (GEDA) (n=22,822; ≥18 years). Physical activity (MVPA-MSE), height/weight, socio-demographic, health and lifestyle factors were assessed by self-report via validated questionnaires. Generalized linear models with Poisson regression were used to assess prevalence ratios of Body Mass Index-derived (BMI) overweight/obesity across categories of physical activity guideline adherence (met neither; MSE only; MVPA only; met both).

RESULTS

Compared to other physical activity groups, meeting both the MVPA-MSE guidelines was associated with the lowest prevalence rate of overweight/obesity (Adjusted Prevalence Ratios [APR] range: 0.25-0.73). Associations between BMI and physical activity were strongest among Class II obesity (APR range: 0.25-0.45). The associations remained consistent after adjusting sociodemographic and lifestyle factors.

CONCLUSIONS

Meeting the combined MVPA-MSE guideline, as suggested in the German national physical activity recommendations, showed the lowest overweight/obesity prevalence. Promoting uptake and adherence of both MVPA and MSE at the population level could help to reduce the public health burden of obesity.

The epidemiology of muscle-strengthening exercise in Europe: A 28-country comparison including 280,605 adults

OBJECTIVE

Muscle-strengthening exercise (use of weight machines, free weights, push-ups, sit-ups), has multiple independent health benefits, and is a component of the Global physical activity guidelines. However, there is currently a lack of multi-country muscle-strengthening exercise prevalence studies. This study describes the prevalence and correlates of muscle-strengthening exercise across multiple European countries.

METHODS

Data were drawn from the European Health Interview Survey Wave 2 (2013-14), which included nationally representative samples (n = 3,774-24,016) from 28 European countries. Muscle-strengthening exercise was assessed using the European Health Interview Survey Physical Activity Questionnaire. Population-weighted proportions were calculated for (1) "insufficient" (0-1 days/week) or (2) "sufficient" muscle-strengthening exercise (≥2 days/week). Prevalence ratios were calculated using multivariate Poisson regression for those reporting sufficient muscle-strengthening by country and by sociodemographic/lifestyle characteristics (sex, age, education, income, self-rated health etc.).

RESULTS

Data were available for 280,605 European adults aged ≥18 years. Overall, 17.3% (95% CI = 17.1%-17.5%) reported sufficient muscle-strengthening exercise (≥2 days/week). Muscle-strengthening exercise was geographically patterned with the lowest prevalence reported in South-eastern European countries (Romania, Malta and Cyprus: range: 0.7%-7.4%), and the highest prevalence in the Nordic countries (Iceland, Sweden, and Denmark: range: 34.1%-51.6%). Older age, insufficient aerobic activity, poorer self-rated health, lower income/education, being female, and being overweight/obese were significantly associated with lower likelihood of reporting sufficient muscle-strengthening exercise, independently of other characteristics.

CONCLUSIONS

Most European adults do not report sufficient muscle-strengthening exercise, and prevalence estimates varied considerably across countries. Low participation in muscle-strengthening exercise is widespread across Europe, and warrants public health attention.

Muscle-strengthening Exercise Epidemiology: a New Frontier in Chronic Disease Prevention

This current opinion provides an overview of the emerging discipline of muscle-strengthening exercise epidemiology. First, we define muscle-strengthening exercise, and discuss its recent addition into the global physical activity guidelines, which were historically mainly focused on aerobic physical activity (walking, running, cycling etc.). Second, we provide an overview of the current clinical and epidemiological evidence on the associations between muscle-strengthening exercise and health, showing a reduced mortality risk, and beneficial cardiometabolic, musculoskeletal, functional and mental health-related outcomes. Third, we describe the latest epidemiological research on the assessment, prevalence, trends and correlates of muscle-strengthening exercise. An overview of recent population estimates suggests that the proportion of adults meeting the current muscle-strengthening exercise guideline (10-30%; ≥ 2 sessions/week) is far lower than adults reporting meeting the aerobic exercise guideline (~ 50%; ≥ 150 min/week). Fourth, we discuss the complexity of muscle-strengthening exercise promotion, highlighting the need for concurrent, coordinated, and multiple-level strategies to increase population-level uptake/adherence of this exercise modality. Last, we explore key research gaps and strategies that will advance the field of muscle-strengthening exercise epidemiology. Our objective is to provide a case for increased emphasis on the role of muscle-strengthening exercise for chronic disease prevention, and most importantly, stimulate more research in this currently understudied area of physical activity epidemiology.

Muscle Strengthening, Aerobic Exercise, and Obesity: A Pooled Analysis of 1.7 Million US Adults

OBJECTIVE

Both aerobic physical activity and muscle-strengthening exercise are recommended for obesity prevention. However, at the population level, the independent and/or combined associations of these physical activity modalities with obesity are unknown. The aim of this study was to examine the associations between aerobic physical activity and muscle-strengthening exercise with obesity among a representative sample of adults.

METHODS

Data were pooled from four US public health surveillance surveys from 2011 to 2017. Cross-sectional associations between adherence to the aerobic physical activity (≥ 150 min/wk) and muscle-strengthening exercise (≥ 2 times/wk) guidelines with different classes of BMI-defined obesity were examined using Poisson regression. Prevalence ratios are reported as both unadjusted and adjusted for sociodemographic and lifestyle characteristics.

RESULTS

Data were available for 1,677,108 adults (≥ 18 years old). Compared with meeting neither guideline (reference category), meeting both guidelines was associated with the lowest adjusted prevalence ratios (APRs) for the following: Class I obesity and above (BMI ≥ 30.0 kg/m² ), APR = 0.54 (95% CI: 0.53-0.54); Class II obesity and above (BMI ≥ 35.0 kg/m² ), APR = 0.32 (95% CI: 0.31-0.33); and Class III obesity and above (BMI ≥ 40.0 kg/m² ), APR = 0.21 (95% CI: 0.20-0.21).

CONCLUSIONS

Among nearly 1.7 million US adults, meeting both aerobic and muscle-strengthening exercise guidelines was associated with a lower obesity prevalence, and associations were more pronounced for higher obesity classes.

Link between Physical Activity Type in Adolescence and Body Composition in Adulthood

PURPOSE

We investigated whether type of physical activity (PA) (sports, running, and fitness/dance) engaged in during adolescence is associated with body composition in late adolescence or early adulthood.

METHODS

Data were drawn from 631 participants in the Nicotine Dependence in Teens study, a prospective investigation of students ages 12-13 yr at inception. Self-report PA data were collected at baseline, in grade 7, and every 3-4 months thereafter during the 5 yr of high school (1999-2005). Anthropometric indicators (height, weight, waist circumference, triceps, and subscapular skinfold thickness) were measured at ages 12, 16, and 24 yr. On the basis of prior exploratory factor analysis, PA was categorized into one of three types (sports, running, and fitness/dance). Regression models estimated the association between number of years participating in each PA type (0-5 yr) during high school and body composition measures in later adolescence or early adulthood.

RESULTS

In multivariable models accounting for age, sex, and parent education, more number of years participating in running during adolescence was associated with lower body mass index, waist circumference, and skinfold thickness in later adolescence and early adulthood (all P < 0.01). This association was no longer apparent in models that accounted for body composition at age 12 yr. The number of years participating in sports was positively associated with body mass index in early adulthood (P = 0.02), but fitness/dance was not statistically significantly associated with any outcome.

CONCLUSION

Sustaining participation in running, but not in other PA types, during adolescence was related to lower body composition in later adolescence and adulthood. However, more research is needed to determine whether this association is attributable to a relationship between PA and body composition in early adolescence.

Muscle-Strengthening Exercise Among 397,423 U.S. Adults: Prevalence, Correlates, and Associations With Health Conditions

INTRODUCTION

Although muscle-strengthening exercise has multiple independent health benefits, little is known about muscle-strengthening exercise participation and associations with adverse health conditions among U.S. adults.

METHODS

In 2017, data were analyzed from the U.S. 2015 Behavioral Risk Factor Surveillance System. During telephone surveys, respondents reported how many times during the past week they engaged in muscle-strengthening exercise. Weighted weekly muscle-strengthening exercise frequencies were calculated for the total sample and across sociodemographic and lifestyle characteristics. A multivariable logistic regression assessed the odds of having self-reported adverse health conditions (e.g., diabetes, coronary heart disease) according to weekly muscle-strengthening exercise frequency.

RESULTS

Data were available on 397,423 adults (aged 18-80 years). Overall, 30.2% (95% CI=29.9, 30.5) met the muscle-strengthening exercise recommendations (two or more times/week) and 57.8% (95% CI=57.5, 58.2) reported no muscle-strengthening exercise. Older age, insufficient aerobic activity, lower income, lower education, poorer self-rated health, being female, and being overweight/obese were significantly associated with lower odds of meeting the muscle-strengthening exercise recommendations independently of other characteristics. After adjusting for confounders (e.g., age, sex, income, smoking, aerobic activity), when compared with those who did none, muscle-strengthening exercise was associated with lower odds for several adverse health conditions, including prevalent diabetes, cancer (non-skin), poor self-rated health, and obesity.

CONCLUSIONS

Three in five U.S. adults do not engage in any muscle-strengthening exercise, despite an association for muscle-strengthening exercise with better health conditions. Future muscle-strengthening exercise promotion strategies should target older adults, females, those with low education/income, and those with a poor health status.

Health outcomes associated with reallocations of time between sleep, sedentary behaviour, and physical activity: a systematic scoping review of isotemporal substitution studies

BACKGROUND

During a 24-h day, each given period is spent in either sedentary behaviour, sleeping, light physical activity (LPA), or moderate-to-vigorous physical activity (MVPA). In epidemiological research most studies have traditionally analysed the associations of these behaviours in isolation from each other; that is, without taking into account the displacement of time spent in the remaining behaviours. In recent years, there has been a growing interest in exploring how all the behaviours across the energy expenditure spectrum influence health outcomes. A statistical model used to investigate these associations is termed an isotemporal substitution model (ISM). Considering the increasing number of ISM-based studies conducted in all age groups, the present paper aimed to: (i) review and summarise findings from studies that employed ISM in sleep, sedentary behaviour, and physical activity research; (ii) appraise the methodological quality of the studies; and (iii) suggest future research directions in this area.

METHODS

A systematic search of ten databases was performed. The Newcastle-Ottawa scale was used to assess the methodological quality of the included studies.

RESULTS

Fifty-six studies met the inclusion criteria, all being of moderate or high methodological quality. Associations were reported for exchanged time varying from one minute to 120 min/day across the studies, with 30 min/day being the most common amount of time reallocated. In total, three different ISM methodologies were used. The most commonly studied health outcomes in relation to isotemporal substitutions were mortality, general health, mental health, adiposity, fitness, and cardiometabolic biomarkers. It seems that reallocations of sedentary time to LPA or MVPA are associated with significant reduction in mortality risk. Current evidence appears to consistently suggest that reductions in mortality risk are greater when time spent sedentary is replaced with higher intensities of physical activity. For adiposity, it seems that reallocating sedentary time to physical activity may be associated with reduced body mass index, body fat percentage, and waist circumference in all age groups, with the magnitude of associations being greater for higher intensities of physical activity. While there is a relatively large body of evidence reporting beneficial associations between the reallocation of time from sedentary behaviour to LPA or MVPA and cardiometabolic biomarkers among adults, there is a lack of studies among children, adolescents, and older adults. Although some studies investigated general health, mental health, and fitness outcomes, further investigation of these topics is warranted. In general, it seems that the strongest association with health outcomes is observed when time is reallocated from sedentary behaviour to MVPA. Most studies did not account for sleep time, which is a major limitation of the current evidence.

CONCLUSIONS

The current evidence indicates that time reallocation between sleep, sedentary behaviour, LPA, and MVPA may be associated with a number of health outcomes. Future studies should employ longitudinal designs, take into account all movement behaviours, and examine a wider range of health, psychological, social, economic, and environmental outcomes.

Programming and supervision of resistance training leads to positive effects on strength and body composition: results from two randomised trials of community fitness programmes

Background

Many sedentary adults have high body fat along with low fitness, strength, and lean body mass (LBM) which are associated with poor health independently of body mass. Physical activity can aid in prevention, management, and treatment of numerous chronic conditions. The potential efficacy of resistance training (RT) in modifying risk factors for cardiovascular and metabolic disease is clear. However, RT is under researched in public health. We report community-based studies of RT in sedentary (Study 1), and overweight and pre-diabetic (Study 2) populations.

Methods

Study 1 - A semi randomised trial design (48-weeks): Participants choosing either a fitness centre approach, and randomised to structured-exercise (STRUC, n = 107), or free/unstructured gym use (FREE, n = 110), or not, and randomised to physical-activity-counselling (PAC, n = 71) or a measurement only comparator (CONT, n = 76). Study 2 - A randomised wait list controlled trial (12-weeks): Patients were randomly assigned to; traditional-supervised-exercise (STRUC, n = 30), physical-activity-counselling (PAC, n = 23), either combined (COMB, n = 39), or a wait-list comparator (CONT, n = 54). Outcomes for both were BF mass (kg), LBM (kg), BF percentage (%), and strength.

Results

Study 1: One-way ANCOVA revealed significant between group effects for BF% and LBM, but not for BF mass or strength. Post hoc paired comparisons revealed significantly greater change in LBM for the STRUC group compared with the CONT group. Within group changes using 95%CIs revealed significant changes only in the STRUC group for both BF% (− 4.1 to − 0.9%) and LBM (0.1 to 4.5 kg), and in FREE (8.2 to 28.5 kg) and STRUC (5.9 to 26.0 kg) for strength.

Study 2: One-way ANCOVA did not reveal significant between group effects for strength, BF%, BF mass, or LBM. For strength, 95%CIs revealed significant within group changes for the STRUC (2.4 to 14.1 kg) and COMB (3.7 to 15.0 kg) groups.

Conclusion

Strength increased in both studies across all RT treatments compared to controls, yet significant improvements in both strength and body-composition occurred only in programmed and/or supervised RT. As general increases in physical activity have limited impact upon body-composition, public health practitioners should structure interventions to include progressive RT.

Trial registration

Study 1: ISRCTN13024854, retrospectively registered 20/02/2018. Study 2: ISRCTN13509468, retrospectively registered 20/02/2018).

Sedentary behavior and compensatory mechanisms in response to different doses of exercise-a randomized controlled trial in overweight and obese adults

BACKGROUND/OBJECTIVES

To examine compensatory changes in sedentary behavior (SB) and light-intensity physical activities (LIPA) in response to a 22-week exercise training program in overweight/obese adults; and to determine if different forms of exercise training and physical activity recommendations interact with these compensatory changes.

SUBJECTS/METHODS

Eighty-nine overweight and obese individuals (body mass index (BMI): 25-34.9 kg/m2, 48% males), aged 18-50 years, were randomized into four intervention groups (strength, endurance, combined strength + endurance and physical activity recommendations) with a 25-30% caloric restriction of total daily energy expenditure for 22 weeks. Energy expenditure was measured by accelerometry before, during and after the program.

RESULTS

LIPA increased significantly (P<0.001) after three months and at the end of intervention compared to baseline (pre: 281±9 min; 3 months: 303±9 min; post: 312±8 min). SB percentage decreased by 5.3 at the end of the intervention (P=0.002). No interactions were observed between groups or sexes. Significant correlations were found between SB and body weight, fat mass, android fat mass and lean body mass before and after the intervention (P<0.05). LIPA was also significantly correlated with all these body composition variables in the pre-intervention, but only correlated with body weight at the end of intervention.

CONCLUSIONS

There were no compensatory changes after a combined exercise and diet program; where minutes in LIPA increased and %SB decreased after the program, without differences among exercise modes. Greater physical activity levels can contribute to a better percentage and distribution of body tissues.

Skeletal Muscle Microvascular-Linked Improvements in Glycemic Control From Resistance Training in Individuals With Type 2 Diabetes

OBJECTIVE

Insulin increases glucose disposal in part by enhancing microvascular blood flow (MBF) and substrate delivery to myocytes. Insulin's microvascular action is impaired with insulin resistance and type 2 diabetes. Resistance training (RT) improves glycemic control and insulin sensitivity, but whether this improvement is linked to augmented skeletal muscle microvascular responses in type 2 diabetes is unknown.

RESEARCH DESIGN AND METHODS

Seventeen (11 male and 6 female; 52 ± 2 years old) sedentary patients with type 2 diabetes underwent 6 weeks of whole-body RT. Before and after RT, participants who fasted overnight had clinical chemistries measured (lipids, glucose, HbA_1c, insulin, and advanced glycation end products) and underwent an oral glucose challenge (OGC) (50 g × 2 h). Forearm muscle MBF was assessed by contrast-enhanced ultrasound, skin MBF by laser Doppler flowmetry, and brachial artery flow by Doppler ultrasound at baseline and 60 min post-OGC. A whole-body DEXA scan before and after RT assessed body composition.

RESULTS

After RT, muscle MBF response to the OGC increased, while skin microvascular responses were unchanged. These microvascular adaptations were accompanied by improved glycemic control (fasting blood glucose, HbA_1c, and glucose area under the curve [AUC] during OGC) and increased lean body mass and reductions in fasting plasma triglyceride, total cholesterol, advanced glycation end products, and total body fat. Changes in muscle MBF response after RT significantly correlated with reductions in fasting blood glucose, HbA_1c, and OGC AUC with adjustment for age, sex, % body fat, and % lean mass.

CONCLUSIONS

RT improves OGC-stimulated muscle MBF and glycemic control concomitantly, suggesting that MBF plays a role in improved glycemic control from RT.

Association of Physical Activity by Type and Intensity With Digestive System Cancer Risk

IMPORTANCE

Accumulating evidence indicates that common carcinogenic pathways may underlie digestive system cancers. Physical activity may influence these pathways. Yet, to our knowledge, no previous study has evaluated the role of physical activity in overall digestive system cancer risk.

OBJECTIVE

To examine the association between physical activity and digestive system cancer risk, accounting for amount, type (aerobic vs resistance), and intensity of physical activity.

DESIGN, SETTING, AND PARTICIPANTS

A prospective cohort study followed 43 479 men from the Health Professionals Follow-up Study from 1986 to 2012. At enrollment, the eligible participants were 40 years or older, were free of cancer, and reported physical activity. Follow-up rates exceeded 90% in each 2-year cycle.

EXPOSURES

The amount of total physical activity expressed in metabolic equivalent of task (MET)-hours/week.

MAIN OUTCOMES AND MEASURES

Incident cancer of the digestive system encompassing the digestive tract (mouth, throat, esophagus, stomach, small intestine, and colorectum) and digestive accessory organs (pancreas, gallbladder, and liver).

RESULTS

Over 686 924 person-years, we documented 1370 incident digestive system cancers. Higher levels of physical activity were associated with lower digestive system cancer risk (hazard ratio [HR], 0.74 for ≥63.0 vs ≤8.9 MET-hours/week; 95% CI, 0.59-0.93; P value for trend = .003). The inverse association was more evident with digestive tract cancers (HR, 0.66 for ≥63.0 vs ≤8.9 MET-hours/week; 95% CI, 0.51-0.87) than with digestive accessary organ cancers. Aerobic exercise was particularly beneficial against digestive system cancers, with the optimal benefit observed at approximately 30 MET-hours/week (HR, 0.68; 95% CI, 0.56-0.83; P value for nonlinearity = .02). Moreover, as long as the same level of MET-hour score was achieved from aerobic exercise, the magnitude of risk reduction was similar regardless of intensity of aerobic exercise.

CONCLUSIONS AND RELEVANCE

Physical activity, as indicated by MET-hours/week, was inversely associated with the risk of digestive system cancers, particularly digestive tract cancers, in men. The optimal benefit was observed through aerobic exercise of any intensity at the equivalent of energy expenditure of approximately 10 hours/week of walking at average pace. Future studies are warranted to confirm our findings and to translate them into clinical and public health recommendation.

Associations between nut consumption and inflammatory biomarkers

BACKGROUND

Increased nut consumption has been associated with reduced risk of cardiovascular disease and type 2 diabetes, as well as a healthy lipid profile. However, the associations between nut consumption and inflammatory biomarkers are unclear.

OBJECTIVE

We investigated habitual nut consumption in relation to inflammatory biomarkers in 2 large cohorts of US men and women.

DESIGN

We analyzed cross-sectional data from 5013 participants in the Nurses' Health Study (NHS) and Health Professionals Follow-Up Study (HPFS) who were free of diabetes. Nut intake, defined as intake of peanuts and other nuts, was estimated from food-frequency questionnaires, and cumulative averages from 1986 and 1990 in the NHS and from 1990 and 1994 in the HPFS were used. Plasma biomarkers were collected in 1989-1990 in the NHS and 1993-1995 in the HPFS. Multivariate linear regression was used to assess the associations of nut consumption with fasting plasma C-reactive protein (CRP, n = 4941), interleukin 6 (IL-6, n = 2859), and tumor necrosis factor receptor 2 (TNFR2, n = 2905).

RESULTS

A greater intake of nuts was associated with lower amounts of a subset of inflammatory biomarkers, after adjusting for demographic, medical, dietary, and lifestyle variables. The relative concentrations (ratios) and 95% CIs comparing subjects with nut intake of ≥5 times/wk and those in the categories of never or almost never were as follows: CRP: 0.80 (0.69, 0.90), P-trend = 0.0003; and IL-6: 0.86 (0.77, 0.97), P-trend = 0.006. These associations remained significant after further adjustment for body mass index. No significant association was observed with TNFR2. Substituting 3 servings of nuts/wk for 3 servings of red meat, processed meat, eggs, or refined grains/wk was associated with significantly lower CRP (all P < 0.0001) and IL-6 (P ranges from 0.001 to 0.017).

CONCLUSION

Frequent nut consumption was associated with a healthy profile of inflammatory biomarkers.

Optimizing Ligand Efficiency of Selective Androgen Receptor Modulators (SARMs)

A series of selective androgen receptor modulators (SARMs) containing the 1-(trifluoromethyl)benzyl alcohol core have been optimized for androgen receptor (AR) potency and drug-like properties. We have taken advantage of the lipophilic ligand efficiency (LLE) parameter as a guide to interpret the effect of structural changes on AR activity. Over the course of optimization efforts the LLE increased over 3 log units leading to a SARM 43 with nanomolar potency, good aqueous kinetic solubility (>700 μM), and high oral bioavailability in rats (83%).

The effects of whey protein with or without carbohydrates on resistance training adaptations

Background

Nutrition intake in the context of a resistance training (RT) bout may affect body composition and muscle strength. However, the individual and combined effects of whey protein and carbohydrates on long-term resistance training adaptations are poorly understood.

Methods

A four-week preparatory RT period was conducted in previously untrained males to standardize the training background of the subjects. Thereafter, the subjects were randomized into three groups: 30 g of whey proteins (n = 22), isocaloric carbohydrates (maltodextrin, n = 21), or protein + carbohydrates (n = 25). Within these groups, the subjects were further randomized into two whole-body 12-week RT regimens aiming either for muscle hypertrophy and maximal strength or muscle strength, hypertrophy and power. The post-exercise drink was always ingested immediately after the exercise bout, 2–3 times per week depending on the training period. Body composition (by DXA), quadriceps femoris muscle cross-sectional area (by panoramic ultrasound), maximal strength (by dynamic and isometric leg press) and serum lipids as basic markers of cardiovascular health, were analysed before and after the intervention.

Results

Twelve-week RT led to increased fat-free mass, muscle size and strength independent of post-exercise nutrient intake (P < 0.05). However, the whey protein group reduced more total and abdominal area fat when compared to the carbohydrate group independent of the type of RT (P < 0.05). Thus, a larger relative increase (per kg bodyweight) in fat-free mass was observed in the protein vs. carbohydrate group (P < 0.05) without significant differences to the combined group. No systematic effects of the interventions were found for serum lipids. The RT type did not have an effect on the adaptations in response to different supplementation paradigms.

Conclusions

Post-exercise supplementation with whey proteins when compared to carbohydrates or combination of proteins and carbohydrates did not have a major effect on muscle size or strength when ingested two to three times a week. However, whey proteins may increase abdominal fat loss and relative fat-free mass adaptations in response to resistance training when compared to fast-acting carbohydrates.

The Prospective Association between Different Types of Exercise and Body Composition

PURPOSE

Despite the widely accepted benefits of exercise on chronic disease risk, controversy remains on the role of exercise in weight loss. This study examined the effect of different exercise types on measures of adiposity across different fat categories.

METHODS

A total of 348 young adults (49% male; 28 ± 4 yr), participating in an ongoing observational study provided valid data over a period of 12 months. Fat mass (FM) and lean mass (LM) were measured via dual x-ray absorptiometry every 3 months. Percent body fat was calculated and used to differentiate between normal-fat, "overfat," and obese participants. At each measurement time point, participants reported engagement (min·wk) in aerobic exercise, resistance exercise, and other forms of exercise.

RESULTS

Most participants (93%) reported some exercise participation during the observation period. Total exercise or specific exercise types did not significantly affect subsequent body mass index after adjusting for sex, ethnicity, age, and baseline values of adiposity and exercise. Resistance exercise affected LM (P < 0.01) and FM (P < 0.01), whereas aerobic exercise only affected FM (P < 0.01). Any exercise type positively affected LM in normal-fat participants (P < 0.04). In overfat and obese participants, FM was reduced with increasing resistance exercise (P ≤ 0.02) but not with aerobic exercise (P ≥ 0.09). Additionally adjusting for objectively assessed total physical activity level did not change these results.

CONCLUSIONS

Despite the limited effects on body mass index, exercise was associated with beneficial changes in body composition. Exercise increased LM in normal-fat participants and reduced FM in overfat and obese adults. Adults with excess body fat may benefit particularly from resistance exercise.