Effect of creatine monohydrate on time to volitional fatigue during an incremental speed running and blood parameters

This study examined the effect of short term creatine monohydrate on time to volitional fatigue during running and blood parameters. Using a random, double blind design, eleven male subjects (age 20.23±1.18 years, height 173.32±4.55 cm, weight 67.05±1.89 kg) participated in an incremental speed running test on treadmill following 5 days of creatine supplementation (CRE; 20 g/d followed by 5 g prior to trial) or control (CON trial). The subjects began the test with a standardized warm-up procedure of a 5 minute and 2 minutes stretching exercise for lower limbs. Each subject initially ran at 9 km/h on a treadmill. Every 2 minutes, the speed was increased by 1km/h until the point of volitional fatigue. Creatine kinase, blood lactate, and blood glucose were measured after each trial. The results showed that the time to volitional fatigue was significantly longer in CRE than that in CON (15.08±0.91min; 11.21±0.91min, respectively) (P < 0.05). Levels of creatine kinase, blood lactate and glucose were significantly higher in CRE compared to CON. This suggests that the ergogenic effect of creatine monohydrate following 5 days of supplementation have a positive impact on endurance exercise.