Q: I was just wondering if paintball, since it tends to get your heart-rate up and usually there's alot of squatting/running/crawling involved, is a rather decent physical activity.

A: I don't know much about paintball unfortunately, but if it does involve all those different modes of activity then it should be a pretty good fat-burner. The only question I'd have is how much of the time you're moving and doing something versus staying in one place hiding? If you're moving at least 50% of the time, then it should very good.