Impact of Four Weeks of a Multi-Ingredient Performance Supplement on Muscular Strength, Body Composition, and Anabolic Hormones in Resistance-Trained Young Men

Risk Associated with the Use of Selected Ingredients in Food Supplements

This review focuses on four new product categories of food supplements: pre-workout, fat burner/thermogenic, brain/cognitive booster, and hormone/testosterone booster. Many food supplements have been shown to be contaminated with unauthorized substances. In some cases, the ingredients in the new categories of dietary supplements were medicinal products or new synthetic compounds added without performing clinical trials. Some of the new ingredients in dietary supplements are plant materials that are registered in the pharmacopoeia as herbal medicines. In other cases, dietary supplements may contain plant materials that have no history of human use and are often used as materials to 'camouflage' stimulants. In the European Union, new ingredients of dietary supplements, according to European Food Safety Authority or unauthorized novel food. Furthermore, selected ingredients in dietary supplements may be prohibited in sports and are recognized as doping agents by World Anti-Doping Agency.

A Systematic Review with Meta-Analysis of the Effect of Resistance Training on Whole-Body Muscle Growth in Healthy Adult Males

We performed a systematic review and meta-analysis to study all published clinical trial interventions, determined the magnitude of whole-body hypertrophy in humans (healthy males) and observed the individual responsibility of each variable in muscle growth after resistance training (RT). Searches were conducted in PubMed, Web of Science and the Cochrane Library from database inception until 10 May 2018 for original articles assessing the effects of RT on muscle size after interventions of more than 2 weeks of duration. Specifically, we obtain the variables fat-free mass (FMM), lean muscle mass (LMM) and skeletal muscle mass (SMM). The effects on outcomes were expressed as mean differences (MD) and a random-effects meta-analysis and meta-regressions determined covariates (age, weight, height, durations in weeks…) to explore the moderate effect related to the participants and characteristics of training. One hundred and eleven studies (158 groups, 1927 participants) reported on the effects of RT for muscle mass. RT significantly increased muscle mass (FFM+LMM+SMM; Δ1.53 kg; 95% CI [1.30, 1.76], p < 0.001; I² = 0%, p = 1.00). Considering the overall effects of the meta-regression, and taking into account the participants’ characteristics, none of the studied covariates explained any effect on changes in muscle mass. Regarding the training characteristics, the only significant variable that explained the variance of the hypertrophy was the sets per workout, showing a significant negative interaction (MD; estimate: 1.85, 95% CI [1.45, 2.25], p < 0.001; moderator: -0.03 95% CI [−0.05, −0.001] p = 0.04). In conclusion, RT has a significant effect on the improvement of hypertrophy (~1.5 kg). The excessive sets per workout affects negatively the muscle mass gain.

The Effects of a Multi-Ingredient Performance Supplement Combined with Resistance Training on Exercise Volume, Muscular Strength, and Body Composition

The effects of a multi-ingredient performance supplement (MIPS) incorporating a mixture of branched chain amino acids, beta-alanine, glutamine, creatine, and piperine on resistance training (RT)-induced adaptations remains unclear. Therefore, the purpose of this study was to investigate the effects of this investigational MIPS during six weeks of RT on performance and body composition. Thirty recreationally trained males and females were recruited for this pair-matched, double-blind, placebo-controlled investigation. Subjects were assigned to consume either an experimental MIPS (MIPS) (n = 15) or a placebo (PLA) (n = 15) concurrently with a six-week periodized RT program. Body composition, one-repetition maximum (1RM), and muscular power were assessed at pre- and post-training. Weekly relative volume load was compared between groups. The MIPS and PLA groups demonstrated a significant increase in total body mass (MIPS = +2.9 ± 1.3%; PLA = +2.5 ± 1.7%) and lean mass (MIPS = +5.0 ± 2.1%; PLA = +3.1 ± 1.9%) (p < 0.001) with no changes in fat mass. There were no group × time interactions for any of the body composition measures. Both groups demonstrated similar improvements in maximum strength for the back squat, bench press, and deadlift as well as lower body power from pre- to post-training (p < 0.001). Within the limitations of the current investigation, results failed to demonstrate the benefits of the experimental MIPS for muscular strength and body composition across six weeks of RT compared to PLA.

Fat metabolism and acute resistance exercise in trained women

This study investigated the effect of acute full-body resistance exercise [RE; one set of 10 repetitions at 40% 1 repetition maximum (1RM) and three sets of 10 repetitions at 65% 1RM] on subcutaneous abdominal adipose tissue (SCAAT) lipolysis and whole body substrate oxidation in young (age: 22 ± 1 yr), normal-weight and body fatness (body mass index: 20 ± 1 kg/m2; %body fat: 28.7 ± 1.4%), resistance-trained women. Microdialysis was used to measure SCAAT lipolysis at baseline, mid-RE, post-RE, and 30 min post-RE, and indirect calorimetry was used to measure whole body substrate oxidation at baseline and immediately post-RE in 13 women. Plasma concentrations of glucose, insulin, nonesterified fatty acids (NEFA), glycerol, growth hormone (GH), epinephrine (Epi), and norepinephrine (NE) were measured at baseline, mid-RE, and post-RE. Lipolysis (dialysate glycerol concentration) was elevated post-RE (baseline: 596.7 ± 82.8, post-RE: 961.4 ± 116.3 µM, P = 0.01). Energy expenditure (baseline: 1,560 ± 49; post-RE: 1,756 ± 68 kcal/day; P = 0.02) and fat oxidation (baseline: 5.64 ± 0.24; post-RE: 7.57 ± 0.41 g/h; P = 0.0003) were elevated post-RE. GH (baseline: 513.1 ± 147.4; mid-RE: 1,288.3 ± 83.9; post-RE: 1,522.8 ± 51.1 pg/ml, P = 0.000), Epi (baseline: 23.2 ± 2.7; mid-RE: 92.5 ± 16.6; post-RE: 84.5 ± 21.4 pg/ml, P = 0.000), and NE (baseline: 139.2 ± 13.6; mid-RE: 850.9 ± 155.3; post-RE: 695.3 ± 93.5 pg/ml, P = 0.000) were higher at mid-RE and post-RE. Therefore, one of the potential mechanisms behind RE-induced fat mass changes in resistance-trained women may be in part due to the accumulated effect of transient increases in SCAAT lipolysis, fat oxidation, and energy expenditure, mediated by GH, Epi, and NE release.

Multi-ingredient pre-workout supplements, safety implications, and performance outcomes: a brief review

In recent years, a new class of dietary supplements called multi-ingredient pre-workout supplements (MIPS) has increased in popularity. These supplements are intended to be taken prior to exercise and typically contain a blend of ingredients such as caffeine, creatine, beta-alanine, amino acids, and nitric oxide agents, the combination of which may elicit a synergistic effect on acute exercise performance and subsequent training adaptations compared to single ingredients alone. Therefore, the purpose of this article was to review the theoretical rationale and available scientific evidence assessing the potential ergogenic value of acute and chronic ingestion of MIPS, to address potential safety concerns surrounding MIPS supplementation, and to highlight potential areas for future research. Though direct comparisons between formulations of MIPS or between a MIPS and a single ingredient are challenging and often impossible due to the widespread use of "proprietary blends" that do not disclose specific amounts of ingredients in a given formulation, a substantial body of evidence suggests that the acute pre-exercise consumption of MIPS may positively influence muscular endurance and subjective mood, though mixed results have been reported regarding the acute effect of MIPS on force and power production. The chronic consumption of MIPS in conjunction with a periodized resistance training program appears to augment beneficial changes in body composition through increased lean mass accretion. However, the impact of long-term MIPS supplementation on force production, muscular endurance, aerobic performance, and subjective measures is less clear. MIPS ingestion appears to be relatively safe, though most studies that have assessed the safety of MIPS are relatively short (less than eight weeks) and thus more information is needed regarding the safety of long-term supplementation. As with any dietary supplement, the use of MIPS carries implications for the athlete, as many formulations may intentionally contain banned substances as ingredients or unintentionally as contaminants. We suggest that athletes thoroughly investigate the ingredients present in a given MIPS prior to consumption. In conclusion, it appears that multi-ingredient pre-workout supplements have promise as an ergogenic aid for active individuals, though further information is required regarding long-term efficacy and safety in a wider variety of populations.

Practical Issues in Evidence-Based Use of Performance Supplements: Supplement Interactions, Repeated Use and Individual Responses

Current sports nutrition guidelines recommend that athletes only take supplements following an evidence-based analysis of their value in supporting training outcomes or competition performance in their specific event. While there is sound evidence to support the use of a few performance supplements under specific scenarios (creatine, beta-alanine, bicarbonate, caffeine, nitrate/beetroot juice and, perhaps, phosphate), there is a lack of information around several issues needed to guide the practical use of these products in competitive sport. First, there is limited knowledge around the strategy of combining the intake of several products in events in which performance benefits are seen with each product in isolation. The range in findings from studies involving combined use of different combinations of two supplements makes it difficult to derive a general conclusion, with both the limitations of individual studies and the type of sporting event to which the supplements are applied influencing the potential for additive, neutral or counteractive outcomes. The repeated use of the same supplement in sports involving two or more events within a 24-h period is of additional interest, but has received even less attention. Finally, the potential for individual athletes to respond differently, in direction and magnitude, to the use of a supplement seems real, but is hard to distinguish from normal day to day variability in performance. Strategies that can be used in research or practice to identify whether individual differences are robust include repeat trials, and the collection of data on physiological or genetic mechanisms underpinning outcomes.

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.