David Goggins, a triathlete, ultramarathoner and retired Navy SEAL, is often nicknamed "the toughest man alive" or "the world's toughest man" for his extreme athletic feats.

DAVID Goggins is known today as the man who wins ultramarathon races and can do countless push-ups and pull-ups. But did you know he also served in the US military for 20 years and went to war in t… ...