It wont be the weed. The THC helps you breathe. It dialates the bronchial tubes and the whole throat, thats why it helps people with asthma.

I'll tel you know, that not many kids your age could do 50 push ups.

You need to do some cardio/breathing work out stuff, but trust me, its not the weed.

[Might be the computer paper you use for joints though ??]