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.

Creatine monohydrate loading improved subjective sleep quality compared to placebo as measured by the Sleep Subjective Quality scale.

• Effect size d = 0.81, p = 0.009
• CrM was also associated with an earlier in-bed time (r = 0.60; p = 0.026)
• 14 physically active men ingested 20 g/day of CrM or placebo for 7 days
• Randomized, double-blind, placebo-controlled crossover design

Creatine monohydrate did not affect objective sleep parameters including sleep latency, sleep efficiency, or total sleep time.

• Sleep latency: t = 0.98; p = 0.35
• Sleep efficiency: t = 0.018; p = 0.98
• Total sleep time: t = 0.25; p = 0.81
• Objective sleep metrics were monitored using wrist-worn actigraphy throughout the 7-day intervention

Creatine monohydrate supplementation improved cognitive performance on the digit cancellation test.

• Effect size d = 0.77; p = 0.013
• Cognitive function was evaluated using the digit cancellation test (DCT)
• Assessment was conducted on the day following completion of the 7-day supplementation phase

Creatine monohydrate enhanced total distance and best distance during the 5-meter shuttle run test.

• Total distance: r = 0.88; p < 0.001
• Best distance: r = 0.76; p < 0.05
• CrM did not significantly affect RPE, fatigue index, or performance decrement during the 5mSRT (all p > 0.05)

Creatine monohydrate resulted in significantly lower muscle soreness scores as measured by the Hooper questionnaire.

• Effect size d = -0.59; p = 0.046
• CrM did not significantly alter other subjective recovery scales compared to placebo up to 72 hours following the end of the supplementation phase (all p > 0.05)
• Recovery and muscle soreness perceptions were evaluated at pre-exercise, 5 min, 24 h, 48 h, and 72 h post-exercise using PRS and DOMS scales

The study employed a randomized, double-blind, placebo-controlled crossover design with 14 physically active men receiving 20 g/day of CrM or placebo for 7 days.

• Participants maintained and standardized their habitual exercise routines across both intervention phases
• Sleep quality was rated using the Sleep Subjective Quality (SSQ) scale and well-being was monitored using the Hooper questionnaire on the day following completion of each supplementation phase
• Trial was registered at the Pan African Clinical Trials Registry (identifier: PACTR202309597156293) on 18 September 2023
• Affective valence was determined using the feeling scale (FS)