Definition of "creatine" [creatine]

• A nitrogenous organic acid, C4H9N3O2, that is found in the muscle tissue of vertebrates mainly in the form of phosphocreatine and supplies energy for muscle contraction. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Players showed high levels of an enzyme called creatine kinase, which is a sign of vigorous exercise."
• "Although muscle damage is usually associated with elevated levels of an enzyme called creatine phosphokinase, the CMAJ research shows that's not always the case."
• "While working in the fitness industry I read somewhere that creatine, which is meant to allow you to work out longer without fatigue or cramping, simply forces your body to absorb water."