Brian J. Sharkey has nearly 40 years of experience as a leading fitness researcher, educator, and author. Sharkey served as director of the University of Montana's Human Performance Laboratory for many years and remains associated with the university and lab as professor emeritus. He is also a consultant with the U.S. Forest Service in the areas of fitness, health, and work capacity. Sharkey is past president of the American College of Sports Medicine and served on the NCAA committee on competitive safeguards and medical aspects of sports, where he chaired the Sports Science and Safety subcommittee, which uses research and data on injury to improve the safety of intercollegiate athletes. He also coordinated the U.S. Ski Team Nordic Sportsmedicine Council. Steven Gaskill is in the department of health and human performance at the University of Montana. Gaskill worked for the U.S. ski team for 10 years as head coach of the Nordic combined (ski jumping and cross-country skiing) and cross-country teams and as director of the coaches' educational programs. He has coached at three Olympic Games, and 20 skiers who have trained under him have competed in the Olympics. In 1992, the U.S. Ski Association named him the U.S. Cross-Country Coach of the Year. Sharkey and Gaskill also coauthored Sport Physiology for Coaches (Human Kinetics, 2006).