TONKONOGI, M., and K. SAHLIN. Physical exercise and mitochondrial function in human skeletal muscle. Exerc. Sport Sci. Rev., Vol. 30, No. 3, pp. 129–137, 2002. Muscle adaptation to endurance training involves qualitative changes in intrinsic properties of mitochondria. After training, the ADP sensitivity of mitochondrion is decreased whereas the effect of creatine on respiration is increased. This results in an improved control of aerobic energy production. Acute exercise does not adversely affect mitochondrial function.