Effects of Whey Protein and Collagen Supplementation

Effects of Whey Protein and Collagen Supplementation on Muscle Mass and Function During Training in Young Adults

The present project aims to investigate the effects of high-quality protein (whey protein) vs. low-quality protein (collagen) on muscle mass and function (e.g., strength and power) during a 10-wk resistance training program in young adults. It will be tested the hypothesis that leucine-matched collagen should promote similar gains on muscle function and mass compared to whey protein supplementation.

The purpose of this study will be to investigate the effects of whey protein vs. leucine-matched collagen supplementation on muscle mass and function after a 10-wk resistance training program. Initially, all participants will be submitted for a 2-wk familiarization period, and then randomized into two groups (N = 11 / group): whey protein group and leucine-matched collagen group. The following variables will be assessed from pre-to post-training: anthropometric, muscle thickness from vastus lateralis and biceps brachii muscles using ultrasound, training load, mean power and peak torque for unilateral arm flexion exercise using a isokinetic dynamometer, countermovement vertical jump, nutritional intake, and testosterone-to-cortisol ratio . Shapiro-Wilk and Levine tests will be used to test the normality and homogeneity of the measurements, respectively. Two-way ANOVA (group x time) tests for repeated measures will be performed to assess changes over time and between groups for all dependent variables. Violation of sphericity will adjust using Greenhouse- Geyser correction. The Bonferroni post-hoc test will detect specific differences between groups. When appropriate, the percentage of change (∆%) will be reported according to the following equation: ∆% = [(pre-average post average) / pre-average mean] × 100. Values will be express as mean ± standard deviation. O significance level α will be 0.05.

35 g of whey protein (7 d/wk) during a 10-wk resistance training program (3 d/wk; 3 sets of 8-12 repetitions with an interval of 1-2 minutes between sets and exercises) involving the leg press, leg extension, and arm flexion exercises. The load will be adjusted weekly.

35 g of collagen (7 d/wk) + 2 g of leucine during a 10-wk resistance training program (3 d/wk; 3 sets of 8-12 repetitions with an interval of 1-2 minutes between sets and exercises) involving the leg press, leg extension, and arm flexion exercises. The load will be adjusted weekly.

Inclusion Criteria: Men and women aged 18-35 years To be eutrophic (not overweight or obese) Exclusion Criteria: To present a history of musculoskeletal disorders Be attending a systematized weight training program for at least six months To make use of medicines that could affect muscle function. To have used ergogenic supplements and anabolic steroids for at least six months before study To have restrictions for exercises practice considering Physical Activity Readiness Questionnaire (PAR-Q) responses.