A physical therapist, Col Pauline Potts, and an exercise physiologist, Kenneth Cooper M.D., both in the US Air Force, were the first to use the term aerobic exercise during the 1960s. Dr. Cooper wanted to find out why some very strong people were poor at long-distance running, swimming and cycling. He researched people's performance in terms of their ability to use oxygen with the use of a bicycle ergometer. In 1968 Dr. Cooper published his book Aerobics. The book included scientific programs using aerobic exercises, such as swimming, running, cycling and walking. The book became a bestseller. All present aerobic programs use Cooper's data as a baseline.