Abstract Rationale: Sleep deprivation has a negative
effect on cognitive and psychomotor performance and
mood state, partially due to decreases in creatine levels in
the brain. Therefore, creatine supplementation should lessen
the negative effects of sleep deprivation. Objectives: The
objective of this study was to examine the effect of creatine
supplementation and sleep deprivation, with mild exercise,
on cognitive and psychomotor performance, mood state,
and plasma concentrations of catecholamines and cortisol.
Method: Subjects were divided into a creatine group (n=10)
and a placebo group (n=9). They took 5 g of creatine
monohydrate or a placebo, dependent on their group, four
times a time a day for 7 days, immediately prior to the
experiment. The study was double blind. Subjects undertook
tests of random movement generation (RMG), verbal and
spatial recall, choice reaction time, static balance and mood
state pre-test (0 h), after 6, 12 and 24 h of sleep deprivation,
with intermittent exercise. They were tested for plasma
concentrations of catecholamines and cortisol at 0 and 24 h.
Results: At 24 h, the creatine group demonstrated sig-
nificantly less change in performance from 0 h (Δ)inRMG,
choice reaction time, balance and mood state. There were no
significant differences between groups in plasma concentra-
tions of catecholamines and cortisol. Norepinephrine and
dopamine concentrations were significantly higher at 24 h
than 0 h, but cortisol were lower. Conclusions: Following
24-h sleep deprivation, creatine supplementation had a
positive effect on mood state and tasks that place a heavy
stress on the prefrontal cortex.
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