Famous racer from over 100 years ago, Bobby Walthour provides an example of discussion of doping in the press over 100 years ago, in 1901.
From "The World", December 1901, showing Madison Square Garden for a six race. At bottom, rider Bobby Walthour says he'll ride without "stimulants"
BOBBY WALTHOUR SAYS HE'LL WIN RACE WITHOUT STIMULANTS
"No, we do not take stimulants in any form, unless it is coffee now and then when we grow a bit sleepy. On the other hand they tell me that these foreigners use drugs. They use strychnine, which is a muscle stimulant. It is a bad business for them and sooner or later they will feel the bad effects of it."
"A man to do well in a race of this kind must keep his body clean and well nourished, and once he begins to take alcohol or strychnine he might as well just stop. I think we will win without much difficulty."