1. VA Medical Center, Research Service, VA Medical Center, Gainesville, Florida.
2. Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida.
3. VA Medical Center, Geriatrics Research, Education, and Clinical Center, VA Medical Center, Gainesville, Florida.
4. Department of Physiological Sciences, University of Florida, Gainesville, Florida.
5. Department of Orthopaedics and Sports Medicine, University of Florida, Gainesville, Florida.
6. Medical University of South Carolina, Charleston, South Carolina.
7. VA Medical Center, Charleston, South Carolina.