1. Division of Exercise Physiology, West Virginia University, Morgantown, West Virginia;
2. Department of Physiology and Pharmacology, West Virginia University, Morgantown, West Virginia;
3. Geriatric Research, Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, Washington;
4. Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, Washington; and
5. Department of Medicine, University of California, San Francisco, San Francisco, California
6. Center for Cardiovascular and Respiratory Sciences, West Virginia University, Morgantown, West Virginia;
7. West Virginia Clinical and Translational Science Institute, West Virginia University, Morgantown, West Virginia;