[boneitis]

I must take a moment to second the bit about proper push-up form.

Fantastic exercise you can do just about anywhere.

I went an hour out of town to watch the Perseids a couple months back. I'm a bit of a gym rat, so I did sets of push-ups to keep my body temperature up, though I'm already shivering by the time I'm starting each set. So, I completely neglected to even think about the proper form (I made the classic mistake of squaring outward my elbows), and further aggravating the circumstances was dealing with the awkward road angles/grades.

With just a handful of sets, I'm pretty sure I permanently damaged my right shoulder. Ugh. The Perseids were fantastic, though :)