Creatine supplementation, sleep deprivation, cortisol, melatonin and behavior

McMorris T, et al.

Published in Physiology & Behavior

Methodology

Randomised, placebo-controlled study in which participants received creatine or placebo for 7 days before 24 hours of sleep deprivation, with repeated cognitive/behavioural testing and salivary cortisol and melatonin sampling.

Key Findings

In sleep-deprived participants, creatine supplementation (20 g/day for 7 days) attenuated the decline in performance on complex tasks requiring executive function and reduced the rise in salivary cortisol during 24 hours of sleep deprivation, without altering melatonin rhythm; simple tasks were unaffected.

Conclusions

During sleep deprivation with moderate-intensity exercise, creatine supplementation only affects performance of complex central executive tasks.

Limitations

Very small sample of young rugby players; short loading protocol; laboratory sleep-deprivation model of limited real-world relevance; multiple behavioural and hormonal endpoints without correction; unreplicated.