Science fair!

What I'm doing for my science fair project is trying to find out if brass instrument players or woodwind players have a larger lung capacity. I'm investigating how much air a person can breathe into a balloon and then measuring the diameter across the balloon. I expect the woodwinds to have a larger lung capacity because it seems to take more air to play a woodwind instrument than a brass instrument. I picked this because it's kinda fun to find out considering I'm in band and most of my friends are too. It's already started up a competition with the band kids! :P