The Ancient Greeks were also the first to use stimulants in the form of potions of brandy and wine as part of their sport training routine. The Roman gladiators also used unspecified stimulants to overcome fatigue and injury. Most of these stimulants were derived from plants.
Source: Holt, R. I., Erotokritou-Mulligan, I. & Sönksen, P. H. (2009). The history of doping and growth hormone abuse in sport. Growth Hormone & IGF Research, 19(4), 320-326. http://doi.org/10.1016/j.ghir.2009.04.009.