It’s a saying that’s been around for years. I tried to track the origin of the phrase, but each lead pointed me towards a separate rabbit hole.
“If you ain’t cheatin’, you ain’t tryin’” is an old NASCAR expression. - Bleacher Report
The “if you ain’t cheating, you ain’t trying” quote was in Scarbrough’s story and was attributed to SMU Head Coach, Sonny Dykes. - bamahammer.com
The first time I heard the saying, “If you’re not cheating, you’re not trying hard enough” — made famous by former Chicago Cubs first basemen, Mark Grace — I was a freshman student-athlete at UCLA.