Oral creatine supplementation facilitates the rehabilitation of disuse atrophy and alters the expression of muscle myogenic factors in humans.
Level 2 - randomized trial
Individual double-blind randomized controlled trial
PubMed 11600695 · doi:10.1111/j.1469-7793.2001.0625c.xd
What was done
A double-blind trial evaluated 22 young healthy volunteers whose right leg was cast-immobilized for 2 weeks, followed by a 10-week knee-extension rehabilitation program (3 sessions per week). Subjects received either oral creatine monohydrate (20 g daily tapering to 5 g daily) or placebo (maltodextrin). Quadriceps cross-sectional area (NMR imaging), maximal knee-extension power (Wmax), and vastus lateralis needle biopsies (fibre diameters and protein expression of MyoD, myogenin, Myf5, and MRF4) were measured before and after immobilization, and after 3 and 10 weeks of rehabilitation.
What was found
Immobilization decreased quadriceps cross-sectional area by approximately 10% and Wmax by approximately 25% identically in both groups, with no changes in myogenic factor protein expression. During rehabilitation, cross-sectional area and Wmax recovered significantly faster in the creatine group compared to placebo (P < 0.05 for both). Post-rehabilitation, myogenin protein expression increased in the placebo group but not in creatine (P < 0.05), whereas MRF4 protein expression increased in the creatine group but not in placebo (P < 0.05). Changes in MRF4 expression correlated with changes in mean muscle fibre diameter (r = 0.73, P < 0.05).
Why it matters
Oral creatine supplementation accelerates muscle mass and strength recovery following disuse atrophy, a response linked to differential expression of muscle regulatory factors such as MRF4.
Limits
The sample size was small (n = 22). The study was conducted in young, healthy volunteers with brief cast immobilization, which may not directly translate to elderly populations or clinical patients recovering from major injury or surgery.
Cited by
- supports Creatine supplementation increases myogenic regulatory factors during rehabilitation from muscle disuse or injury.