Robert Hoffman, MS , retired from the U.S. Army as a lieutenant colonel in 1991. During his 22 years in the military, Hoffman completed assignments around the world. He commanded a brigade headquarters company in Germany, a ranger company in Vietnam, and a Special Forces SCUBA detachment at Fort Bragg, North Carolina. He also commanded the 4th Ranger Training Battalion at Fort Benning, Georgia, where in addition to working with rangers, Hoffman trained U.S. drug enforcement agents who were being deployed in South America. Hoffman spent three years as the director of training for the Army's Soldier Physical Fitness School and helped to develop the Army's Total Fitness program. He also spent four years as a professor in the department of physical education at West Point. While there, he was an assistant cross country and track coach and a junior varsity basketball coach. Hoffman was certified as a fitness instructor by the American College of Sports Medicine (ACSM) and as a master fitness trainer by the U.S. Army. He received a master's degree in physical education from Indiana University and was a member of the American Society of Law Enforcement Trainers. Hoffman was also the author of Running Together: The Family Book of Jogging , and he helped write the army's Physical Fitness Training field manual. Hoffman passed away in July 2016. Thomas R. Collingwood, PhD , has been involved in implementing law enforcement programs for 40 years. He developed and directed the continuing education division of the Cooper Institute for Aerobics Research, where he created the institute's police instructor course that has trained more than 10,000 police fitness coordinators. He also designed the FitForce national law enforcement fitness program. Collingwood has worked with more than 200 law enforcement agencies worldwide to design fitness programs and has conducted validation studies to define job-related fitness standards for 100 federal, state, and local law enforcement agencies. He is the author of 10 books and more than 100 publications in the field. Collingwood was a military policeman with the U.S. Army, a police psychologist with the Dallas Police Department, and a training director for the Kentucky Department of Justice. He has served as the national fitness director for the American Society of Law Enforcement Trainers and as a special advisor on law enforcement fitness to the President's Council on Physical Fitness and Sports and the International Association of Chiefs of Police (IACP). He also was an advisor for the redesign of the U.S. Army's Physical Readiness program. Collingwood holds a master's degree in exercise science from the University of Kentucky and a doctorate in psychology from the University of Buffalo, and he is a certified health and fitness director with the American College of Sports Medicine. The IACP, U.S. Drug Enforcement Administration, U.S. Marshals Service, and U.S. Secret Service have all recognized Collingwood for his work in the field of law enforcement fitness. He was the recipient of the Healthy American Fitness Leaders award presented by the President's Council on Physical Fitness and Sports and the National Jaycees. Collingwood resides with his wife, Gretchen, in Richardson, Texas.