ABSTRACT
Creatine has been well-studied as an endogenous metabolite, nutrient and dietary supplement. This chapter provides background information on creatine metabolism and summarizes the effects of supplemental creatine on health, exercise performance and training adaptations. Creatine is a guanidino phosphate that was first isolated from animal meat by the French chemist and philosopher Michel Eugene Chevreul in 1832. Numerous studies have confirmed creatine monohydrate supplementation can increase intramuscular creatine content. Creatine supplementation can increase intramuscular creatine and phosphorylcreatine concentration by approximately 20% within seven days, although this response varies between individuals. Because creatine and phosphorylcreatine are an important source of energy for muscle contraction during high-intensity activity, an increase in intramuscular creatine and phosphorylcreatine should increase available energy during exercise, prolonging the work capacity of skeletal muscle, delaying the onset of muscle fatigue and improving performance. Intermittent exercise, characterised by bouts of low- and high-intensity activity, has unique physiological and metabolic requirements.
