The response to muscle unloading during spaceflight varies tremendously from individual to individual. Factors contributing to this variability need to be identified if effective and efficient countermeasures to muscle wasting are to be developed. The aims of this investigation are to: 1) develop a new model for the study of atrophy in the arm; and 2) determine whether resistance training influences the muscle atrophy response. Two groups of subjects (matched on strength, equal numbers of men and women) will undergo 21 days of arm unloading. One group, TR/UN (n=16), will perform eight weeks of resistance training prior to unloading. The second group, UNLOAD (n=16), will not train prior to unloading. The unloading model, based on previous research by the P.I., primarily will consist of daytime suspension of the non-dominant elbow and shoulder. The arm will be free during sleeping and bathing to allow for some degree of mobility, similar to that during spaceflight. Atrophy will be assessed using magnetic resonance imaging (MRI) to measure the cross sectional area of muscle in the upper arm. Other dependent variables include muscle strength and fatigability, and arm limb volume. Data from this investigation will demonstrate the utility of a new model to study atrophy in the arm, indicate the degree to which the variability in the atrophy is influenced by prior muscle use, and generate data to support future proposals to investigate the influence of gender and genetics on atrophy, as well as strategies to counter muscle wasting during spaceflight.
| Mail: | Dr. Mary P. Miles |
|
Department of Health and Human Development |
| Montana State University | |
| Bozeman, MT 59717 |
| E-mail: | mmiles@montana.edu |
| Phone: | (406) 994-6678 |
| FAX: | (406) 994-6314 |
Montana Space Grant Home