Creatine is often taken by athletes as a supplement for those wishing to gain muscle mass (bodybuilding). There are a number of forms but the most common are creatine monohydrate (creatine complexed with a molecule of water) and Creatine ethyl ester (CEE).
Creatine increases the activity of satellite cells, which make muscle hypertrophy possible. Creatine supplementation appears to increase the number of myonuclei that satellite cells will ‘donate’ to damaged muscle fibers, which increases the potential for growth of those fibers.
Changes in substrate oxidation may influence the inhibition of fat mass loss associated with creatine after weight training when they discovered that fat mass did not change significantly with creatine but decreased after the placebo trial in a 12-week study on ten active men. The study also showed that 1-RM bench press and total body mass increased after creatine, but not after placebo. The underlying effect of creatine on body composition has yet to be determined, no effect on body composition, but had less overall emphasis on metabolic effects.
Creatine use is not considered doping and is not banned by the majority of sport-governing bodies.