There's a great story about an early effort at doping by the Arsenal football club. In 1925, Arsenal's manager, Leslie Knighton, was visited by a "distinguished West End doctor" who offered "courage-pills" (probably amphetamines) for an upcoming game against West Ham United. Having been reassured the pills were safe, Knighton accepted.
Just before the match began, Knighton's team took their pills. The problems began when the referee postponed the game due to thick fog.
Getting the boys back to Highbury that afternoon was like trying to drive a flock of lively young lions.
The entire team was violently restless and impossibly thirsty. The next week, the team dutifully swallowed the pills again. The match was again postponed. Once more came edginess and thirst. When they finally played West Ham, the energetic, drugged up team managed a nil-all draw. In the rematch, the poor old Arsenal players rebelled. No more drugs.
The only reason we know about the episode is because Knighton included it in his 1948 memoir, under the chapter title "I Dope Arsenal for a Cup Tie". At no time did Knighton have any ethical qualms. Neither, it seems, did the team. They had no sense that this was cheating. But they wanted to keep it secret nonetheless.