cyclists,
athletes,
weight lifters,
skiers,
snooker players,
rugby players,
american footballers
all the above came to mind without too much thought,
some think that doping is a new problem.
About a 100 years ago an Italian running in the olympic marathon
collapsed just before the finishing line, he was found to have taken
strychnine which was a regular thing at that time.
Not so long ago the English rugby union sent out a memo to all clubs
with 5 groups of banned substances.
Many years ago when I was involved with cycle racing there were over
400 substances on the banned list.