Effects of Creatine Monohydrate Loading on Sleep Metrics, Physical Performance, Cognitive Function, and Recovery in Physically Active Men: A Randomized, Double-Blind, Placebo-Controlled, Crossover Trial.
Level 2 - randomized trial
Individual randomized double-blind placebo-controlled crossover trial
PubMed 41470776 · doi:10.3390/nu17243831
What was done
Fourteen physically active men completed a randomized, double-blind, placebo-controlled crossover trial evaluating 7 days of creatine monohydrate loading (20 g/day) versus placebo while maintaining standardized exercise routines. Sleep metrics were tracked continuously using wrist-worn actigraphy. Post-supplementation testing included the Sleep Subjective Quality (SSQ) scale, Hooper well-being questionnaire, a 5 m shuttle run test (measuring total distance, best distance, performance decrement, fatigue index, and rating of perceived exertion), the Feeling Scale for affective valence, the Digit Cancellation Test (DCT) for cognitive function, and perceived recovery status and DOMS scales measured pre-exercise and up to 72 hours post-exercise.
What was found
Creatine significantly improved subjective sleep quality compared to placebo (d = 0.81, p = 0.009) and was associated with an earlier in-bed time (r = 0.60, p = 0.026). Objective actigraphy measures showed no significant differences in sleep latency (t = 0.98, p = 0.35), sleep efficiency (t = 0.018, p = 0.98), or total sleep time (t = 0.25, p = 0.81). Creatine improved cognitive performance on the DCT (d = 0.77, p = 0.013), lowered muscle soreness on the Hooper questionnaire (d = -0.59, p = 0.046), and increased 5 m shuttle run total distance (r = 0.88, p < 0.001) and best distance (r = 0.76, p < 0.05). Creatine had no significant effect on rating of perceived exertion, fatigue index, performance decrement, or post-exercise recovery scores up to 72 hours (all p > 0.05).
Why it matters
This study provides preliminary evidence that short-term creatine loading can enhance cognitive function and subjective sleep perceptions alongside sprint performance, though it did not alter objective actigraphy-derived sleep duration or efficiency.
Limits
The sample size was very small (n = 14) and restricted entirely to physically active men. Objective sleep was evaluated via wrist actigraphy rather than gold-standard polysomnography, and the abstract does not report the length of the washout period between crossover phases.