Feats of strength

I'm not sure; maybe you have to be a cyclist, and know the pain that occurs after a long climb, and how fatigue has set into your legs, and how every pedalstroke is simultaneously a pain-generator, a motivator, and chinese water torture all in one.

Maybe only cyclists can appreciate the moment when somebody in a huge climb just pulls away from the rest of the pack, and conquers the pain with sheer strength.

But maybe you don't have to be a cyclist. If you can watch this video and not simply be amazed, then maybe you need to get your butt on a bike. ;-)