Effects of oral creatine and resistance training on serum myostatin and GASP-1.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 20026378 · doi:10.1016/j.mce.2009.12.019
What was done
In a double-blind randomized controlled trial, 27 healthy male participants (mean age 23.42 ± 2.2 years) were assigned to one of three groups for 8 weeks: control (CON), resistance training plus placebo (RT+PL), or resistance training plus creatine supplementation (RT+CR). The training protocol consisted of 3 sessions per week (3 sets of 8-10 repetitions at 60-70% of 1RM for whole-body exercise). Blood sampling for serum myostatin and GASP-1, muscular strength testing, and body composition analysis (whole-body DEXA) were performed at baseline, week 4, and week 8.
What was found
Resistance training caused a significant decrease in serum myostatin and an increase in GASP-1. Creatine supplementation combined with resistance training resulted in a greater decrease in serum myostatin than resistance training alone (p < 0.05), but had no additional effect on GASP-1 (p > 0.05). Exact numerical concentrations, effect sizes, and quantitative results for muscle strength and DEXA lean mass were not provided in the abstract.
Why it matters
This trial suggests that creatine's ability to augment resistance training adaptations may operate partly through enhanced suppression of myostatin, a catabolic regulator of muscle mass.
Limits
The sample size was small (27 participants across three arms) and limited strictly to young healthy men. The abstract omits the creatine dosage regimen, numerical values, confidence intervals, and quantitative results for strength and body composition outcomes.
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