1. Department of Exercise Science, University of South Carolina, Public Health Research Center, 921 Assembly Street, Columbia, SC 29208, USA.
2. Department of Epidemiology, West Virginia University, Morgantown, WV 26506, USA.
3. Department of Kinesiology, Iowa State University, Ames, IA 50011, USA.
4. Department of Health and Physical Activity, University of Pittsburgh, Pittsburgh, PA 15260, USA.
5. South Carolina Statewide Cancer Prevention and Control Program, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA.
6. Department of Epidemiology and Biostatistics, University of South Carolina, Columbia, SC 29208, USA.
7. College of Nursing, University of South Carolina, Columbia, SC 29208, USA.