ESSENTIAL AMINO ACIDS AND RESISTANCE EXERCISE IN AGING

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This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The loss of muscle mass leads to overall weakness, immobility and physical dependence, and can be responsible for an impaired response to stress, which is associated with higher mortality rates during infection, surgery, and trauma. Amino acids and weight lifting can both increase muscle size. It has been shown that muscle growth post-exercise is less in the elderly as compared to young volunteers. However, there have been no studies that have examined the combined effect of amino acids and resistance exercise. We hypothesize that amino acid ingestion following a bout of weight lifting exercise will improve short-term muscle growth in older men. The specific aims are to determine if 20 grams of essential amino acids ingested one hour following a bout of weight lifting exercise will stimulate short-term muscle growth in older men to the same extent as seen in the young. Six healthy young and older male volunteers will be enrolled. One hour following the exercise session each subject will receive 20 grams of essential amino acids. We will then assess changes in blood amino acid content, hormone changes such as insulin and testosterone from the blood samples. Each muscle sample will be used to measure muscle protein synthesis and to assess changes in cell signaling pathways the control protein synthesis. These studies will provide insight into why muscle loss is occurring with age and will then help us to develop scientifically-based interventions for improving muscle size.