Creatine supplementation at 300mg/kg for one week (loading with no maintenance) in youth subject to six repeated 35m sprints (10s rest, known as the Running-based Anaerobic Sprint Test or RAST) noted that the increased average and peak power output seen in creatine was not met with a reduction in fatigue, although there was an attenuation in inflammation from exercise (TNFα and CRP).
Synthesis primarily takes place in the kidney and liver, with creatine then being transported to the muscles via the blood. The majority of the human body's total creatine and phosphocreatine stores is located in skeletal muscle, while the remainder is distributed in the blood, brain, and other tissues. Typically, creatine is produced endogenously at an estimated rate of about 8.3 mmol or 1 gram per day in young adults. Creatine is also obtained through the diet at a rate of about 1 gram per day from an omnivorous diet. Some small studies suggest that total muscle creatine is significantly lower in vegetarians than non-vegetarians, as expected since foods of animal origin are the primary source of creatine. However, subjects happened to show the same levels after using supplements.