Oh, exercise. A necessary evil and a beautiful experience, wrapped up in an awkward bow. As a broke musician, I have to get a bit creative in the world of exercising. Due to the fact that I don't want to pay $50 a month for a gym membership, I have become quite the YouTube workout aficionado. My favorite thing to do right now is yoga. Here are some of my favorite yoga vids on YouTube that'll make you sweat your tail off.
(And just for reference, I'm at an intermediate level. Not a beginner, but I'm certainly not advanced. I can't do the majority of the arm balances and acrobatic stuff, so when the video asks me to do those, I try it for a minute, and then I just hop around 'til the next pose. :) )
Hope this will help you save money, too!