Effect of creatine supplementation during resistance training on muscle accretion in the elderly.

Sarcopenia, defined as the age-related loss of muscle mass, is a serious health concern. Contributing factors to sarcopenia include physical inactivity and undernutrition. Resistance training has a positive effect on muscle mass in the elderly. However, muscle loss is still observed in older adults who perform weight bearing exercise; suggesting that nutrition is important. Creatine supplementation has the potential to increase muscle accretion during resistance training, although the mechanism for its ergogenic effect is unclear. Creatine has the potential to increase cellular hydration and myogenic transcription factors and facilitate the up-regulation of muscle specific-genes such as myosin heavy chain possibly leading to muscle hypertrophy.