Written by Bill Orban, the Royal Canadian Air Force Exercise Plans published in 1961 and United States Air Force Colonel Kenneth Cooper's books "Aerobics" (1968) and mass-market version "The New Aerobics" (1979) helped to launch modern fitness culture.[3][7][8][9] In the United States, a "Boot Camp Workout" audio compact cassette recorded by a Marine Corps drill instructor was released in 1984.[10] Indoor "boot camp workouts" at health clubs around the U.S. were popular in 1998.[7][8][11][12]