[wyre]

Certainly. TFA states the cannabis users experiences more exertion, while also contributing to more positive effect, enjoyment, and runner's high. Sure, if you took two identical runners the non-smoker would run faster/longer, but there is no such thing as two identical runners and the effects of smoking would be negligible compared to other factors such as sleep, diet, training, and recovery. If smoking cannabis can significantly improve any or all of those factors for the athlete their performance will be better overall than the benefits that not smoking grants.