1. Introduction
Muscle mass, MPS, muscle mass accrual
The aim of this study was to compare the potential additional effect of chia flour, whey protein, and a placebo juice to resistance training on fat-free mass (FFM) and strength gains in untrained young men. Eighteen healthy, untrained young men underwent an 8-week whole-body resistance training program, comprising three sessions per week. Subjects were randomized into three groups that after each training session consumed: (1) 30 g whey protein concentrate containing 23 g protein (WG), (2) 50 g chia flour containing 20 g protein (CG), or (3) a placebo not containing protein (PG). Strength tests (lower- and upper-limb one repetition maximum (1 RM) tests) and body composition analyses (dual-energy X-ray absorptiometry; DXA) were performed before (PRE) and after (POST) the intervention. Resistance training increased FFM and the 1 RM for each of the strength tests similarly in the three groups. FFM increased by 2.3% in WG (Muscle mass is essential for health and sport performance. Muscle mass is tightly regulated by muscle protein synthesis (MPS) and muscle protein breakdown. The main stimuli for MPS are amino acid availability and resistance training, which synergically affect MPS, contributing to muscle mass accrual over time [Protein supplementation has repeatedly been demonstrated to enhance lean mass and strength gains after resistance training in healthy young subjects with an optimal daily protein intake around 1.6 g/kg/d [Here, we hypothesized that chia flour supplementation would enhance the effects of a resistance training program on fat-free mass (FFM) and strength gains to the same extent as whey protein, due to its high protein and 