1. Division of Biostatistics, and
2. Department of Health and Human Performance, Human Performance Laboratory, University of Montana, Missoula, Montana 59812;
3. Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana 70808;
4. Departments of Genetics and Psychiatry, Washington University School of Medicine, Saint Louis, Missouri 63110;
5. Department of Health and Kinesiology, Texas A&M University, College Station, Texas 77843;
6. Department of Kinesiology, Indiana University, Bloomington, Indiana 46405;
7. School of Kinesiology and Leisure Studies, University of Minnesota, Minneapolis, Minnesota 55455