Resistance Exercise Training and Amino Acid Leucine Supplementation in Frail Elderly Women

Frailty is a clinical entity associated with an increase in risk for disease and death and becomes more common as people age. Frailty has a strong relationship with the age-related loss of muscle and strength, termed sarcopenia. Sarcopenia and frailty are strongly associated with disability, especially in women. Adequate protein intake, the amino acid leucine, and resistance exercise training have been individually shown to increase muscle mass to varying degrees. However, no studies have investigated how a longer-term resistance exercise training program with leucine supplementation when protein intake is optimized could increase muscle mass in frail and pre-frail elderly women. In addition, this is the population that stands the most to gain from such an intervention. The purpose of this study is to investigate the effects of the amino acid leucine added to resistance exercise training on muscle mass and physical performance in frail and pre-frail elderly women with adequate protein intake. We hypothesize that combining leucine in diet with an exercise program would be superior to exercise alone in stimulating muscle protein synthesis and phosphorylation status of muscle cellular key-regulatory proteins, leading to enhanced gains in muscle performance. A total of 24 subjects will take part in this study, conducted at the McGill University Health Centre (MUHC) Royal Victoria Hospital and the Institut Universitaire de Gériatrie de Montréal (IUGM). All subjects will undergo adjustments to their diet to optimize protein intake and a resistance exercise training program. Half of the participants will receive a supplement of powdered leucine (an amino acid), and the other half of the participants will receive a placebo in the same powder form. Neither the participants nor the study investigators will know which participants are receiving the leucine nor which are receiving the placebo. Each subjects participation in this study will involve 4 total visits: 2 initial s