Creatine is stored in muscles as creatine phosphate. The level of creatine phosphate in muscles is a main determinant of muscle power output. Creatine supplementation is a method that is designed to increase muscle creatine levels and muscle performance.
A recent study tested the effects of creatine supplementation on repeated bouts of all-out exercise. Subjects were tested after 4 days of creatine supplementation (25 g/day) or control (no creatine). The test involved subjects cycling for 30 seconds as hard as possible 3 times in a row with 6 minutes recovery between bouts.
Four days of creatine supplementation increased muscle creatine levels by 16%. The greater muscle creatine resulted in enhanced power output during the first cycling test (6%) and improved even more during bout 2 (7%) and bout 3 (10%).
The results confirm that short-term creatine supplementation augments muscle creatine levels and muscle power output during intermittent high-intensity exercise.