Fatigue is a complex phenomenon that can be evoked by peripheral and central factors. The effects of creatine supplementation (CrS) on peripheral and central fatigue factors after exhaustive aerobic exercise are not fully understood. Thus the purpose of this study was to investigate central and peripheral fatigue factors after an exhaustive aerobic exercise following CrS. Twenty untrained male subjects participated in a placebo (Plc, n=10)/creatine (Cr, n=10), double-blind study conducted over 7 days period. The Cr group received 20 g (4 × 5 g) creatine monohydrate per day and Plc group received the same dosage of a glucose polymer. Each subject performed a graded treadmill exercise test to complete exhaustion. Blood lactate levels increased (P<0.05) immediately after the exercise in the Cr and Plc groups and there was no significant difference between two groups. While, blood lactate concentration decreased after the exercise in the both groups (P<0.05), the decrease of blood lactate concentration was quickly in the Cr group than the Plc group (P<0.05). Additionally, although serotonin: dopamine ratio was lower in the Cr group immediately after the exercise and during the recovery, no significant difference between two groups was observed. These findings suggest that although CrS effective to reduce blood lactate after an exhaustive aerobic exercise, central fatigue index was not affected by CrS.
