Whole egg may have potential benefits for enhancing muscle mass, independent of its protein content. The yolk comprises ∼40% of the total protein in an egg, as well as containing several nonprotein nutrients that could possess anabolic properties (e.g., microRNAs, vitamins, minerals, lipids, phosphatidic acid and other phospholipids). Therefore, the purpose of this narrative review is to discuss the current evidence as to the possible effects of egg yolk compounds on skeletal muscle accretion beyond those of egg whites alone. The intake of whole egg seems to promote greater myofibrillar protein synthesis than egg white intake in young men. However, limited evidence shows no difference in muscle hypertrophy when comparing the consumption of whole egg versus an isonitrogenous quantity of egg white in young men performing resistance training. Although egg yolk intake seems to promote additional acute increases on myofibrillar protein synthesis, it does not seem to further enhance muscle mass when compared to egg whites when consumed as part of a high-protein dietary patterns, at least in young men. This conclusion is based on very limited evidence and more studies are needed to evaluate the effects of egg yolk (or whole eggs) intake on muscle mass not only in young men, but also in other populations such as women, older adults, and individuals with muscle wasting diseases.
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The Effect of Whole Egg Intake on Muscle Mass: Are the Yolk and Its Nutrients Important?
Heitor O. Santos, Gederson K. Gomes, Brad J. Schoenfeld, and Erick P. de Oliveira
Isolated Leucine and Branched-Chain Amino Acid Supplementation for Enhancing Muscular Strength and Hypertrophy: A Narrative Review
Daniel L. Plotkin, Kenneth Delcastillo, Derrick W. Van Every, Kevin D. Tipton, Alan A. Aragon, and Brad J. Schoenfeld
Branched-chain amino acids (BCAA) are one of the most popular sports supplements, marketed under the premise that they enhance muscular adaptations. Despite their prevalent consumption among athletes and the general public, the efficacy of BCAA has been an ongoing source of controversy in the sports nutrition field. Early support for BCAA supplementation was derived from extrapolation of mechanistic data on their role in muscle protein metabolism. Of the three BCAA, leucine has received the most attention because of its ability to stimulate the initial acute anabolic response. However, a substantial body of both acute and longitudinal research has now accumulated on the topic, affording the ability to scrutinize the effects of BCAA and leucine from a practical standpoint. This article aims to critically review the current literature and draw evidence-based conclusions about the putative benefits of BCAA or leucine supplementation on muscle strength and hypertrophy as well as illuminate gaps in the literature that warrant future study.
Effect of Two- Versus Three-Way Split Resistance Training Routines on Body Composition and Muscular Strength in Bodybuilders: A Pilot Study
Alex S. Ribeiro, Brad J. Schoenfeld, Danilo R.P. Silva, Fábio L.C. Pina, Débora A. Guariglia, Marcelo Porto, Nailza Maestá, Roberto C. Burini, and Edilson S. Cyrino
The purpose of this study was to compare different split resistance training routines on body composition and muscular strength in elite bodybuilders. Ten male bodybuilders (26.7 ± 2.7 years, 85.3 ± 10.4 kg) were randomly assigned into one of two resistance training groups: 4 and 6 times per week (G4× and G6×, respectively), in which the individuals trained for 4 weeks, 4 sets for each exercise performing 6–12 repetitions maximum (RM) in a pyramid fashion. Body composition was assessed by dual energy X-ray absorptiometry, muscle strength was evaluated by 1RM bench-press testing. The food intake was planned by nutritionists and offered individually throughout the duration of the experiment. Significant increases (p < .05) in fat-free mass (G4× = +4.2%, G6× = +3.5%) and muscular strength (G4× = +8.4%, G6× = +11.4%) with no group by time interaction were observed. We conclude that 4 and 6 weekly sessions frequencies of resistance training promote similar increases in fat-free mass and muscular strength in elite bodybuilders.
Effect of Conjugated Linoleic Acid Associated With Aerobic Exercise on Body Fat and Lipid Profile in Obese Women: A Randomized, Double-Blinded, and Placebo-Controlled Trial
Alex S. Ribeiro, Fábio Luiz C. Pina, Soraya R. Dodero, Danilo R. P. Silva, Brad J. Schoenfeld, Paulo Sugihara Júnior, Rodrigo R. Fernandes, Décio S. Barbosa, Edilson S. Cyrino, and Julio Tirapegui
The aim of this study was to analyze the effects of 8 weeks of conjugated linoleic acid (CLA) supplementation associated with aerobic exercise on body fat and lipid profile on obese women. We performed a randomized, double-blinded and placebo-controlled trial with 28 obese women who received 3.2 g/day of CLA or 4 g/day of olive oil (placebo group) while performing an 8-week protocol of aerobic exercise. Dietary intake (food record), body fat (dual-energy X-ray absorptiometry), and biochemical analysis (blood sample) were assessed before and after the intervention period. Independent of CLA supplementation, both groups improved (p < .05) oxygen uptake (CLA group, 13.2%; PLC group, 14.8%), trunk fat (CLA group, −1.0%; PLC group, −0.5%), leg fat (CLA group, −1.0%; PLC group, −1.6%), and total body fat (CLA group, −1.7%; PLC group, −1.3%) after the 8-week intervention. No main effect or Group × Time interaction was found for total cholesterol, triglycerides, and plasma lipoproteins (p > .05). We conclude that CLA supplementation associated with aerobic exercise has no effect on body fat reduction and lipid profile improvements over placebo in young adult obese women.
Effects of Whey Protein Supplementation Associated With Resistance Training on Muscular Strength, Hypertrophy, and Muscle Quality in Preconditioned Older Women
Paulo Sugihara Junior, Alex S. Ribeiro, Hellen C.G. Nabuco, Rodrigo R. Fernandes, Crisieli M. Tomeleri, Paolo M. Cunha, Danielle Venturini, Décio S. Barbosa, Brad J. Schoenfeld, and Edilson S. Cyrino
The purpose of this study was to investigate the effect of whey protein (WP) supplementation on muscular strength, hypertrophy, and muscular quality in older women preconditioned to resistance training (RT). In a randomized, double-blind, and placebo (PLA)-controlled design, 31 older women (67.4 ± 4.0 years, 62.0 ± 6.9 kg, 155.9 ± 5.7 cm, and 25.5 ± 2.4 kg/m2) received either 35 g of WP (n = 15) or 35 g of PLA (n = 16) over a 12-week study period while performing an RT program three times a week. Dietary intake, one-repetition maximum test, and skeletal muscle mass by dual-energy X-ray absorptiometry were assessed before and after the intervention period. Both groups showed significant (p < .05) improvements in skeletal muscle mass and total strength, and the WP group realized greater increases (p < .05) in these measures compared with PLA (skeletal muscle mass: WP = +4.8% vs. PLA = +2.3%; strength: WP = +8.7% vs. PLA = +4.9%). Muscular quality increased (p < .05) in both groups (WP = +2.9% vs. PLA = +1.5%) without statistical differences (p > .05) noted between conditions. We conclude that WP supplementation in combination with RT induces higher increases in both strength and hypertrophy in older women preconditioned to RT.
Creatine Supplementation Does Not Influence the Ratio Between Intracellular Water and Skeletal Muscle Mass in Resistance-Trained Men
Alex S. Ribeiro, Ademar Avelar, Witalo Kassiano, João Pedro Nunes, Brad J. Schoenfeld, Andreo F. Aguiar, Michele C.C. Trindade, Analiza M. Silva, Luís B. Sardinha, and Edilson S. Cyrino
The authors aimed to compare the effects of creatine (Cr) supplementation combined with resistance training on skeletal muscle mass (SMM), total body water, intracellular water (ICW), and extracellular water (ECW) in resistance-trained men as well as to determine whether the SMM/ICW ratio changes in response to the use of this ergogenic aid. Twenty-seven resistance-trained men received either Cr (n = 14) or placebo (n = 13) over 8 weeks. During the same period, subjects performed two split resistance training routines four times per week. SMM was estimated from appendicular lean soft tissue assessed by dual-energy X-ray absorptiometry. Total body water, ICW, and ECW were determined by spectral bioelectrical impedance. Both groups showed improvements (p < .05) in SMM, total body water, and ICW, with greater values observed for the Cr group compared with placebo. ECW increased similarly in both groups (p < .05). The SMM/ICW ratio did not change in either group (p > .05), whereas the SMM/ECW ratio decreased only in the Cr group (p < .05). A positive correlation was observed (p < .05) between SMM and ICW changes (r = .71). The authors’ results suggest that the increase in muscle mass induced by Cr combined with resistance training occurs without alteration of the ratio of ICW to SMM in resistance-trained men.
Effect of Resistance Training Systems on Oxidative Stress in Older Women
Alex S. Ribeiro, Rafael Deminice, Brad J. Schoenfeld, Crisieli M. Tomeleri, Camila S. Padilha, Danielle Venturini, Décio S. Barbosa, Luís B. Sardinha, and Edilson S. Cyrino
The purpose of this study was to investigate the effect of two different resistance training (RT) systems on oxidative stress biomarkers in older women. Fifty-nine older women (67.9 ± 5.0 years) were randomly assigned to one of three groups. Two training groups performed an 8 week RT program either in traditional (TD, n = 20) or a pyramid (PR, n = 20) system 3 times per week, or a control group (CG, n = 19). The TD program consisted of 3 sets of 8–12 RM with constant load for the 3 sets, whereas the PR training consisted of 3 sets of 12/10/8 RM with incremental loads for each set. As compared with the CG, both TD and PR achieved upregulation of the antioxidant system as evidenced by higher (p < .05) values of total radical-trapping antioxidant parameter plasma concentration after intervention (TD= 930.4 ± 160.0 µmolTrolox, PR= 977.8 ± 145.2 µmolTrolox, CG= 794.4 ± 130.2 µmolTrolox). For the protein oxidation adducts, TD and PR presented lower (p < .05) scores compared with CG (TD= 91.2 ± 25.0 µmol/L, PR= 93.0 ± 30.3 µmol/L, CG= 111.0 ± 20.4 µmol/L). However, there were no differences (p < .05) between trained groups in the antioxidant capacity markers and in the protein oxidation adducts markers. The results suggest that 8 weeks of progressive RT promotes an improvement in markers of oxidative stress in older women independent of the load-management RT system.