it'll decrease your athletic ability. it's a depressant and the only benefit would be a decrease in sensation/awareness of pain...if you're a linebacker for a football team you may consider popping a few before a game, otherwise i'd suggest you dont. keep in mind vicodin is not only hydrocodone but acetominophen(tylenol)...increased heart rate and blood pressure and a higher risk of tremors or ultimately seizures in higher doses right before extreme physical exertion...
Heres a link to a CNS depressants reference page. I use it once in a while (aside from the trusty info over at www.erowid.org) http://www.healthandage.com/html/res/com/ConsDrugs/DrugCats/CentralNervousSystemDepressants.html