1 Physical Medicine and Rehabilitation Service, Department of Veterans Affairs, Northern California Health Care System, 10535 Hospital Way, Sacramento, CA, 95655-1200, USA. mdhoffman@ucdavis.edu.
2 Department of Physical Medicine and Rehabilitation, University of California Davis Medical Center, Sacramento, CA, USA. mdhoffman@ucdavis.edu.
3 Ultra Sports Science Foundation, El Dorado Hills, CA, USA. mdhoffman@ucdavis.edu.
4 Centre for Sport Research, School of Exercise and Nutrition Sciences, Deakin University, Victoria, Australia.
5 Department of Nutrition, Dietetics and Food, Monash University, Victoria, Australia.