I was running today…to the beach and back…listening to my Dave Matthews jams and a young (early 20’s??) man passed me. He was just running with all of his might, of course not to be “beat” by a woman. So, I’m still in my zone around a 10 minute-mile and a few minutes up ahead he was bending over, trying to catch his breath and breathing heavily. So, I passed him and guess what? Here he comes again! Same thing happened, he seemed to have bonked and I passed him again, barely breathing hard or sweating. Restrained endurance is pure satisfaction.