Hall explains that during the event

Hall explains that during the event he often asks himself why he would put himself through such agony; the answer becomes clear when the end is in sight. "It's a long endurance event, and several times during the day when you're in the middle of nowhere and you're away from spectators, you think, ‘Why am I doing this?'" says Hall. "But you get to the finish line, and it answers those questions all at once. It's an absolute adrenaline rush, and it's very emotional."The science behind the rush really comes down to the finish line, the top of the mountain, the next big wave ...