The effect of protein timing on muscle strength and hypertrophy: a meta-analysis

Protein timing is a popular dietary strategy designed to optimize the adaptive response to exercise. The strategy involves consuming protein in and around a training session in an effort to facilitate muscular repair and remodeling, and thereby enhance post-exercise strength- and hypertrophy-related adaptations. Despite the apparent biological plausibility of the strategy, however, the effectiveness of protein timing in chronic training studies has been decidedly mixed. The purpose of this paper therefore was to conduct a multi-level meta-regression of randomized controlled trials to determine whether protein timing is a viable strategy for enhancing post-exercise muscular adaptations. The strength analysis comprised 478 subjects and 96 ESs, nested within 41 treatment or control groups and 20 studies. The hypertrophy analysis comprised 525 subjects and 132 ESs, nested with 47 treatment or control groups and 23 studies. A simple pooled analysis of protein timing without controlling for covariates showed a small to moderate effect on muscle hypertrophy with no significant effect found on muscle strength. In the full meta-regression model controlling for all covariates, however, no significant differences were found between treatment and control for strength or hypertrophy. The reduced model was not significantly different from the full model for either strength or hypertrophy. With respect to hypertrophy, total protein intake was the strongest predictor of ES magnitude. These results refute the commonly held belief that the timing of protein intake in and around a training session is critical to muscular adaptations and indicate that consuming adequate protein in combination with resistance exercise is the key factor for maximizing muscle protein accretion

The data do not seem to support a benefit to BCAA supplementation during periods of caloric restriction

J Int Soc Sports Nutr 13:1-015-0112-9, 2016 describe the efficacy of branched chain amino acid (BCAA) supplementation and resistance training for maintaining lean body mass during a calorie-restricted diet, and claim that this occurs with concurrent losses in fat mass. However, the reported results appear to be at odds with the data presented on changes in fat mass. This letter discusses the issues with the paper

Body composition changes associated with fasted versus non-fasted aerobic exercise

It has been hypothesized that performing aerobic exercise after an overnight fast accelerates the loss of body fat. The purpose of this study was to investigate changes in fat mass and fat-free mass following four weeks of volume-equated fasted versus fed aerobic exercise in young women adhering to a hypocaloric diet. Twenty healthy young female volunteers were randomly assigned to 1 of 2 experimental groups: a fasted training (FASTED) group that performed exercise after an overnight fast (n = 10) or a post-prandial training (FED) group that consumed a meal prior to exercise (n = 10). Training consisted of 1 hour of steady-state aerobic exercise performed 3 days per week. Subjects were provided with customized dietary plans designed to induce a caloric deficit. Nutritional counseling was provided throughout the study period to help ensure dietary adherence and self-reported food intake was monitored on a regular basis. A meal replacement shake was provided either immediately prior to exercise for the FED group or immediately following exercise for the FASTED group, with this nutritional provision carried out under the supervision of a research assistant. Both groups showed a significant loss of weight (P = 0.0005) and fat mass (P = 0.02) from baseline, but no significant between-group differences were noted in any outcome measure. These findings indicate that body composition changes associated with aerobic exercise in conjunction with a hypocaloric diet are similar regardless whether or not an individual is fasted prior to training

Novas perpectivas para a análise estatística da resposta da pressão arterial ao treinamento resistido em mulheres idosas hipertensas

O objetivo principal do estudo foi apresentar procedimentos estatísticos para uma melhor interpretação dos dados sobre a responsividade, explicar como lidar com o efeito da regressão a média (RM) e descrever como determinar alterações clinicamente importantes na pressão arterial (PA) pelo cálculo da diferença clínica (DC). Vinte e sete mulheres idosas hipertensas foram incluídas e o treinamento resistido (TR) consistiu em um modelo linear periodizado. O TR durou 10 semanas, com duas sessões realizadas por semana. Os responsivos foram classificados com base nas diferenças da pressão arterial sistólica (PAS) entre os momentos T1 (primeiras 3 semanas) e T4 (semanas 9-10). As análises estatísticas no presente estudo foram realizadas utilizando a ANOVA de medidas repetidas, análise de covariância (ANCOVA) e modelo linear misto (MLM). Conclui-se que quando uma ANOVA de medidas repetidas é aplicada, os resultados mostram uma redução não significativa de -2,24 mmHg, mas a classificação dos participantes por responsividade fornece uma interpretação diferente dos resultados. Além disso, a PAS inicial foi o preditor mais potente da resposta pós-exercício da PAS, conforme analisado pela RM. Finalmente, as reduções de -2,24 mmHg não foram estatisticamente significativas e nem clinicamente importantes, mas caíram dentro do erro de medida.The main goal was to present statistical procedures for a better data interpretation of responsiveness, explain how to deal with RTM effect, and describe how to determine clinically important changes in BP from significant real difference (SRD). Twenty-seven hypertensive elderly women were included, and RT consisted of a periodized linear model. The RT lasted 10 weeks, with two sessions performed per week. Responders were classified on the basis of SBP differences between time-points T1 (first 3 weeks) and T4 (weeks 9-10). Statistical analyses were performed using One-Way Repeated Measures ANOVA, an analysis of covariance (ANCOVA), the linear mixed model (LMM) was used in the present study, and SRD was also calculated. In conclusion, when one-way repeated measure ANOVA was conducted to determine whether there was a statistically significant difference in SBP levels over the course of 10-week RT, results showed a non-significant reduction of -2.24 mmHg, while classifying subjects by responsiveness provides a different perspective of the results. Furthermore, initial SBP was the more powerful predictor of post-exercise SBP response, as analyzed by the regression to the mean effect. Finally, the reductions of -2.24 mmHg was not statistically significant nor clinically meaningful, but fell within the measurement error of the SBP measurements

Efficacy of progressive versus severe energy restriction on body composition and strength in concurrent trained women

Purpose This study evaluated the concurrent training (CT) effect in combination with either progressive energy restriction (PER) or severe energy restriction (SER) on body composition and strength-related variables in resistance-trained women. Methods Fourteen women (29.5 ± 3.8 years; 23.8 ± 2.8 kg·m −2 ) were randomly assigned to a PER (n = 7) or SER (n = 7) group. Participants performed an 8-week CT program. Pre- and post-intervention measures of fat mass (FM) and fat-free mass (FFM) were assessed by dual-energy X-ray absorptiometry and strength-related variables were assessed through 1-repetition maximum (in the squat and bench press) and countermovement jump. Results Significant reductions in FM were observed in PER and SER (Δ = − 1.7 ± 0.4 kg; P = < 0.001; ES = − 0.39 and Δ = − 1.2 ± 0.6 kg; P = 0.002; ES = − 0.20, respectively). After correcting FFM for fat-free adipose tissue (FFAT), no signifi- cant differences for this variable were found either in PER (Δ = − 0.3 ± 0.1; P = 0.071; ES = − 0.06) or in SER (Δ = − 0.2 ± 0.1; P = 0.578; ES = − 0.04). There were no significant changes in the strength-related variables. No between-group differences were found in any of the variables. Conclusion A PER has similar effects to a SER on body composition and strength in resistance-trained women performing a CT program. Given that PER is more flexible and thus may enhance dietary adherence, it might be a better alternative for FM reduction compared to SER.Funding for open access publishing: Universidad Málaga/ CBUA. Funding for open access charge: Universidad de Málaga / CBU

The impact of sarcopenic obesity on inflammation, lean body mass, and muscle strength in elderly women

Objective: The objective of this study was to apply the newly standardized definition for sarcopenia from the Foundation for the National Institutes of Health (FNIH) and the current definition for obesity to 1) determine the prevalence of sarcopenic obesity (SO) in obese elderly women; 2) compare the muscle strength, lean body mass, and markers of inflammation between obese elderly women with SO and nonsarcopenic obesity (NSO), and 3) elucidate the relationship between appendicular lean mass adjusted for body mass index (aLM/BMI) with muscle strength, lean body mass, and obesity indices. Methods: A total of 64 elderly obese women (age: 68.35±6.04 years) underwent body composition analysis by dual-energy X-ray absorptiometry. Participants were classified into two groups according to the definition of SO and NSO. Blood samples were collected for total cholesterol, triglycerides, high-density lipoprotein, low-density lipoprotein, uric acid, urea, interleukin-6 (IL-6), glucose, and creatine kinase (CK) measurements. Results: The SO group presented a significantly greater BMI, fat (%), glucose, a marginal trend toward significance for uric acid, and IL-6 compared to the NSO group. In addition, the SO group displayed lower values for muscle strength and lean body mass. From a correlation standpoint, a higher aLM/BMI was positively associated with lean body mass and muscle strength and negatively associated with a lower BMI and percentage body fat. Conclusion: The definition criteria from FNIH and obesity permit the ability to illustrate the prevalence and identify SO in elderly women with low muscle mass, low muscle strength, and impaired markers of inflammation

The Effect of Different Resistance Training Load Schemes on Strength and Body Composition in Trained Men

The purpose of this study was to evaluate the impact of moderate-load (10 RM) and low-load (20 RM) resistance training schemes on maximal strength and body composition. Sixteen resistance-trained men were randomly assigned to 1 of 2 groups: a moderate-load group (n = 8) or a low-load group (n = 8). The resistance training schemes consisted of 8 exercises performed 4 times per week for 6 weeks. In order to equate the number of repetitions performed by each group, the moderate load group performed 6 sets of 10 RM, while the low load group performed 3 sets of 20 RM. Between-group differences were evaluated using a 2-way ANOVA and independent t-tests. There was no difference in the weekly total load lifted (sets × reps × kg) between the 2 groups. Both groups equally improved maximal strength and measures of body composition after 6 weeks of resistance training, with no significant between-group differences detected. In conclusion, both moderate-load and low-load resistance training schemes, similar for the total load lifted, induced a similar improvement in maximal strength and body composition in resistance-trained men

Metabolic and hormonal responses to different resistance training systems in elderly men

Objective: To compare acute and sub-acute responses in hormonal profile and metabolic parameters in elderly people who participated in two methods of strength training (ST) with equalized loads.Methods and materials: A total of 12 elder individuals (653years) were randomly assigned to two training methods: constant intensity (CI, 3 sets of 10 repetitions with 75% of 1RM) and variable intensity (VI, 1st set: 12 repetitions at 67% of 1RM>2nd set: 10 repetitions at 75% of 1RM and 3rd set: 8 repetitions at 80% of 1RM). Both methods included the following exercises: leg press, knee extension, and squat with 1min rest intervals between sets. Free speed of execution and maximum range of movement were encouraged throughout each set for both protocols. Blood samples were analyzed included glucose, testosterone (T), cortisol (C), T/C rate, growth hormone (GH), and lactate at 2 and 24h post intervention.Results: There were no observed differences in glucose, testosterone, GH, and lactate concentrations both at 2 and 24h after the execution of the two training methods. However, significant increases in the levels of T/C rate and decrease on cortisol were observed immediately post exercise for both protocols.Conclusions: Although no significant differences were observed between the two interventions in relation to the hormonal and metabolic parameters analyzed, both training methods promoted a favorable response, with a slight superiority noted for the CI method relative to the hormonal profile.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Sao Judas Tadeu Univ USJT, Post Grad Program Phys Educ & Aging Sci, Translat Physiol Lab, Sao Paulo, BrazilNove de Julho Univ UNINOVE, Dept Phys Educ & Biophoton, Sao Paulo, BrazilFed Univ Sao Paulo UNIFESP, Obes Study Grp GEO, Interdisciplinary Lab Metab Dis, Santos, BrazilPraia Grande Coll FPG, Fac Phys Educ, Praia Grande, BrazilUniv West Scotland, Inst Clin Exercise & Hlth Sci, Hamilton, EnglandCUNY, Dept Hlth Sci, Bronx, NY USAFed Univ Sao Paulo UNIFESP, Obes Study Grp GEO, Interdisciplinary Lab Metab Dis, Santos, BrazilWeb of Scienc

The effect of inter-set rest interval duration on muscle hypertrophy: A systematic review with meta-analysis

The purpose of this systematic review with meta-analysis will be to investigate the effect of inter-set rest interval duration during resistance training on measures of muscle hypertroph