1. Military Performance Division, United States Army Research Institute of Environmental Medicine, Natick, MA 01760, USA
2. Endocrine Unit, Massachusetts General Hospital, Boston, MA 02114, USA
3. The Warrior Health Research Institute of Military Physiology, Israel Defense Forces' Medical Corps
4. Heller Institute of Medical Research, Sheba Medical Center, Tel-Hashomer 52621, Israel
5. Center for Advanced Orthopedic Studies, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA
6. Department of Orthopaedic Surgery, Harvard Medical School, Boston, MA 02215, USA