Counsilman was born in Birmingham, Alabama, but grew up and learned to swim in St. Louis, Missouri. He swam collegiately for the Ohio State University under coach Mike Peppe; and while in college set world-bests in the 50 and 300 yard breaststrokes. During World War II, Counsilman served in the United States Army Air Forces in Italy as a B-24 Liberator pilot with the 455th Bomb Group of the Fifteenth Air Force. Post Ohio State, Counsilman went on to earn a master's degree at the University of Illinois, where he also served as an assistant coach, before pursuing doctorate degree in physiology from the University of Iowa where he was also the assistant coach under David Armbruster. It was at the University of Iowa that Counsilman coached his first two Olympians-Wally Ris and Bowen Stassforth. Following award of his doctorate, the now-dubbed "Doc" began teaching and coaching at Cortland State University, where he would remain from 1952 to 1957 leading into his time at Indiana University. While coaching at Cortland State University he took on at the time Freshman George Breen as a member of the swim team in 1953. George Breen would be molded by Doc Counsilman into a standout athlete, he would break the world record for the 1500 meter freestyle at an unspecified event and qualify for the 1956 Olympic Games in Melbourne where he set another world record in the 1500 meter freestyle with a time of 17:52.9 during the preliminaries, but wouldn't meet it, receiving bronze overall. Once at Indiana University, he would go on to continue to train George Breen for the 1500 where he would swim in the 1960 Olympics in Rome, earning another bronze metal. Doc Councilman would end up creating who is considered one of the finest Olympic distance swimmers in United States history.
Doc Counsilman is known as one of the greatest swimming coaches of all time. He was also an innovator in the sport, pioneering underwater filming, and even watching swimmers underwater, as can be seen in Royer Pool at Indiana University today. He was also the instigator of hypoventilation training, a training method which consists of swimming with reduced breathing frequency. Counsilman died in Bloomington, Indiana, in 2004, after suffering from Parkinson's disease. He has been inducted into various Hall of Fames, including: the International Swimming Hall of Fame, Ohio State Varsity "O" Hall of Fame, IU Athletics, the American Swimming Coaches Association and SUNY Cortland.