With NFL training camps in full swing, "Survivor" survivor Jimmy Johnson offered an apt comparison in describing his experience doing the CBS reality show in Nicaragua.
He said it was tougher than three-a-days.
"At least if you're going through those practices, you get a good night's sleep and you have food in your stomach," Johnson said Tuesday. "We got no sleep, and there were days we were existing on less than 100 calories a day. It was extremely difficult."