We always did the 12 minute stopwatch run on the third day of cross country practice, a sure sign the fun of summer had ended. My high school coach like use, Greg Wilson, would bring dozens of students with to a local track in our Kansas City suburb at 6 a.m., click his and force us to run around the oval, lap after lap time, as many as we could finish. The local police had their training center atop a hill nearby, and, below it, our track felt like a jail, runners trapped, splayed across the lanes, many walking after a few minutes. When Wilson shouted into a megaphone to stop, even the well-conditioned few were hunched over and heaving. Whether you were one of the fastest or slowest runners, 12-minute run’s induced misery did not discriminate.

I assumed for years my coach had concocted this excruciating workout. In fact, my pain was universal.

The 12-minute run was and is perhaps the world’s most effective and popular conditioning test. I was enduring the same torture as Pele did as a soccer star, as Michael Jordan did as a college basketball player.

Cooper has achieved international fame for inspiring the modern exercise movement through his book Aerobics. He’s less known for creating the 12-minute , or, as others call it, the Cooper Test. This month marks the 50th anniversary of the Cooper Test’s publication, and in that time the 12-minute run has been used by championship World Cup, NFL, and college basketball teams, police recruits, and thousands upon thousands of high school and amateur athletes worldwide, many of whom, like high school me, have no idea how the test came to be and what makes it an ideal conditioning tool for.