Charles E. Yesalis, MPH, ScD, is known worldwide for his research and teaching related to the use of anabolic steroids and other performance-enhancing drugs.

Dr. Yesalis received his Bachelor of Science and Master of Public Health degrees from the University of Michigan and he was awarded his doctoral degree by the Johns Hopkins University School of Hygiene and Public Health in 1975. He then joined the faculty at Johns Hopkins for one year. Dr. Yesalis was a member of the Department of Preventive Medicine and Environmental Health at the University of Iowa, College of Medicine from 1976-1986. Currently he is Professor of Health Policy and Administration and Exercise and Sport Science at The Pennsylvania State University.

Dr. Yesalis has testified six times before the U.S. Congress and acted as a consultant for the White House Office of National Drug Control Policy, the U.S. Senate Judiciary Committee, the National Institute on Drug Abuse, the Drug Enforcement Administration, and the Food and Drug Administration. Dr. Yesalis is the author and editor of four books on drugs in sport: The Steroids Game, Anabolic Steroids in Sport and Exercise (First and Second Editions), and Performance-Enhancing Substances in Sport and Exercise with Dr. Bahrke.

Michael S. Bahrke, PhD, is an Editor in the Scientific, Technical, and Medical Division of Human Kinetics Publishers. He has authored over 50 scientific papers on performance-enhancing substances and has made numerous presentations on the topic at various scientific meetings including the American College of Sports Medicine, American Psychiatric Association, National Strength and Conditioning Association, and the U.S. Drug Enforcement Administration. Dr. Bahrke has served as director for a National Institute on Drug Abuse-funded anabolic steroids research grant in Chicago. In 2002, along with Dr. Yesalis, he co-edited Performance-Enhancing Substances in Sport and Exercise.

Between Dr. Yesalis and Dr. Bahrke, they have directed the first national study of anabolic steroid use among adolescents and were the first to present evidence of psychological dependence on anabolic steroids. In addition, they have studied the incidence of steroid use among elite power lifters, collegiate athletes, and professional football players. In 1993, using nationwide data, they demonstrated the association between anabolic steroid use and violent behavior as well as an association with the use of other illicit drugs and alcohol. They also presented an estimate of lifetime AS use in the U.S. population (over one million). A recent study conducted by Dr. Yesalis showed a significant increase in AS use among teenage girls and boys since 1990.