Effect of creatine supplementation during cast-induced immobilization on the preservation of muscle mass, strength, and endurance.
Level 2 - randomized trial
Individual randomized crossover trial
PubMed 19130643 · doi:10.1519/jsc.0b013e31818efbcc
What was done
Seven creatine-naïve healthy men aged 18–25 years were evaluated in a single-blind crossover study to test the effects of creatine on muscle preservation during upper-limb disuse. Participants had their dominant or nondominant arm randomly assigned to immobilization in a long-arm plaster cast at 90 degrees elbow flexion. Subjects received placebo (maltodextrin; 4 x 5 g/day) during days 1–7 and creatine (4 x 5 g/day) during days 15–21, with casts removed during days 8–14 and 22–29. Lean tissue mass (DXA), 1RM isometric elbow flexion/extension strength, and muscular endurance (isokinetic repetitions at 60% 1RM) were measured at baseline, post-cast, and study completion.
What was found
During immobilization, creatine supplementation resulted in significantly better retention across all measured parameters compared to placebo (all p < 0.05): - Lean tissue mass: +0.9% with creatine vs. -3.7% with placebo - Elbow flexor strength: -4.1% with creatine vs. -21.5% with placebo - Elbow flexor endurance: -9.6% with creatine vs. -43% with placebo - Elbow extensor strength: -3.8% with creatine vs. -18% with placebo - Elbow extensor endurance: -6.5% with creatine vs. -35% with placebo
Why it matters
This demonstrates that short-term creatine loading can attenuate the loss of muscle mass, strength, and endurance caused by acute limb immobilization, even without exercise.
Limits
The sample size is very small (n = 7) and restricted to young healthy men. The single-blind crossover design used a fixed treatment sequence (placebo followed by creatine) rather than a randomized order, leaving potential for order or learning effects. Immobilization was limited to 7 days in the upper limb.
Cited by
- supports In a cast-immobilization trial, creatine supplementation maintained muscle strength.