If I was clever I'd put this video in a place where I can watch it often. I'm not so you will have to follow my link to Roni's post today. Future readers may not find it so I'll tell you a ssecret. It's a guy who lost 120 lbs and ran a marathon. That doesn't do it justice so believe me when I say you have to go to Roni's post and view it.
Maybe one day I will be clever enough to give you a direct link that will stand the test of time.