Asker Jeukendrup, PhD, is a professor of exercise metabolism in the School of Sport and Exercise Sciences at the University of Birmingham in Edgbaston, Birmingham, UK. He is an active researcher credited with many of the new findings in sport nutrition in the past decade. He is a registered sport and exercise nutritionist, having worked with many elite athletes and clubs, including the professional cycling team Rabobank, the Chelsea Football Club, UK Athletics, the British Olympic Association, African runners, and several Olympic and world champions. Jeukendrup has published extensively in sport nutrition and was an invited delegate to the IOC Consensus Conference on Sports Nutrition in Lausanne in 2003. He is a fellow of the AmericanCollege of Sports Medicine and the EuropeanCollege of Sport Sciences, the Physiological Society, the Nutrition Society, BASES, the New York Academy of Sciences, and the American Diabetic Association. He is also the editor of the European Journal of Sport Sciences. In his leisure time, he enjoys running, cycling, and competing in triathlons. He has completed more than 17 Ironman-distance races, including the Ironman Hawaii four times. Michael Gleeson, PhD,is a professor of exercise biochemistry in the School of Sport, Exercise and Health Sciences at LoughboroughUniversity in Loughborough, Leicestershire, UK. Gleeson is an active researcher in sport nutrition and has worked with numerous world-class athletes and professional football clubs. He has taught sport nutrition at the university level and has published extensively in scientific and medical journals. He also was an invited delegate to the IOC Consensus Conference on Sports Nutrition in Lausanne in 2003. He has a particular interest and expertise in the effects of exercise, training, and nutrition on immune function and has been both vice president and president of the International Society of Exercise and Immunology. Gleeson is also a fellow of the EuropeanCollege of Sport Sciences and a member of the AmericanCollege of Sports Medicine, the Physiological Society, and the British Association of Sport and Exercise Sciences. He enjoys playing tennis, hill walking, and watching football and films.