I don't want to put a lot of work into my hair, then have it ruined in gym.?

At my school, the first period is girls gym and they work us really hard because my school has a good rep for sports. I don't wanna wake up at 6 AM to go perfect my hair just to hang out in front of my school in the morning, I'd rather it last the whole day, including through athletics. But the rule is if your hair can be put up, it IS up. So my real question is, If i go style my hair (like straighten it or curl it) then work out in athletics with it up in a pony tail, then take it down after and get dressed will it still be straight/curled? Oh and i have no time to totally re-do my do after athletics, so that's not an option. Thanks in advance!