I've brought it up to my parents before (I'm 16, also). I want to try it, but I'm not in any hurry right now.
My suggestions are to help them acclimate to the concept by bringing it up a few times, then showing them how passionate you are about trying it. Let them know that at the very least, you will stop if you feel ill or can't take it anymore.
"On the bright side, Mom, I'll be able to do more chores around the house..."
