[stadiaKab]

In mushing and other endurance sports I would think that drugs that help you stay awake and alert would be an advantage.

exactly. Lance Mackey tokes up - he has a medical marajuana license - and he made a big stink when the testing came about (though he is exempt as he uses it for pain management due to his cancer a few years ago). He then said that it didn't give any advantage, but it kept him alert... the way he said it though sounded like 1. the total opposite of what a dope high looks like and 2. was a major advantage to those that didn't get to use it...

he won his 3rd title off the stuff entirely, his 4th he was using again... the last two years though, more deserving men have won.