Snell worked for a tobacco company before moving to the United States of America in 1971 to further his education. He gained a B.S. in human performance from the University of California, Davis, and then a Ph.D. in exercise physiology from Washington State University. He joined University of Texas Southwestern Medical Center at Dallas as a research fellow in 1981. He was associate professor, Department of Internal Medicine and also director of their Human Performance Center. A member of the American College of Sports Medicine, Snell was honoured in 1999 as an Inaugural Inductee, International Scholar, into the Athlete Hall of Fame, University of Rhode Island.