> The numbers in that study make absolutely no sense as anyone who has exercised will tell you.

I've exercised, they make sense to me.

> Bicycling at 12-13mph same level of energy expenditure as push-ups? Nope. > Running at 9 min/mile more exertion than push-ups? Nope.

I agree that to me bicycling at 12-13mph or running at 9 min/mile sounds easier than push-ups. But that is because push-ups exercise a much smaller muscle group, that is much easier exhausted (and that is much less trained in my case). I can run at 9 min/mile for hours, but will exhaust my chest muscles before 50 push-ups. That doesn't mean that energy wise one is harder than the other. My heart rate during push-ups or pull-ups doesn't surpass 140 bpm, which is about the same as when running 9 min/mile.

If you look at the physics: your center of gravity moves about 20cm up and down during a push-up (in 1 second). During running your center of gravity moves up and down 10 cm twice-thrice a second.