Int J Sport Nutr Exerc Metab. 2012 Jul 4. [Epub ahead of print]
Whey Protein Before and During Resistance Exercise Has No Effect on Muscle Mass and Strength in Untrained Young Adults.
Source
Faculty of Kinesiology and Health Studies, University of Regina, Regina, Saskatchewan, Canada.
Abstract
PURPOSE:
To determine the effects of whey protein before and during resistance exercise (RE) on body composition and strength in young adults.
METHODS:
Participants were randomized to ingest whey protein (PRO; 0.3g·kg-1 protein; n=9, 24.58±1.8 yrs, 88.3±17.1 kg, 172.5±8.0 cm) or placebo (PLA; 0.2g·kg-1 corn-starch maltodextrin + 0.1g·kg-1 sucrose; n=8, 23.6±4.4 yrs, 82.6±16.1 kg, 169.4±9.2 cm) during RE (3 sets of 6-10 repetitions for 9 whole-body exercises), which was performed 4 days per week for 8 weeks. Protein and placebo were mixed with water (600ml) and 50% of the solution containing 0.15g·kg-1 of protein or placebo was consumed immediately prior to the start of exercise and ~1.9% of the remaining solution containing ~0.006g·kg-1 of protein or placebo was consumed immediately following each training set. Before and after the study, measures were taken for lean tissue mass (dual energy x-ray absorptiometry), muscle size of the elbow and knee flexors and extensors and ankle dorsi flexors and plantar flexors (ultrasound), and muscle strength (1-repetition maximum chest press).
RESULTS:
There was a significant increase (p<0.05) in muscle size of the knee extensors (PRO: 0.6±0.4 cm, PLA: 0.1±0.5 cm), knee flexors (PRO: 0.4±0.6 cm, PLA: 0.5±0.7 cm), ankle plantar flexors (PRO: 0.6±0.7 cm, PLA: 0.8±1.4 cm), and chest press strength (PRO: 16.6±11.1 kg, PLA: 9.1±14.6 kg) over time, with no differences between groups.
CONCLUSION:
The ingestion of whey protein immediately before the start of exercise and again following each training set has no effect on muscle mass and strength in untrained young adults.
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