An IV drip of sugar might be fine for getting through a 23 mile sprint, but to be a true endurance athlete, fat is becoming the fuel of choice.
What do professional cyclist Dave Zabriskie, ultramarathon runner Timothy Olson, and gold-medal triathlete Simon Whitfield have in common? All of these elite endurance athletes have pushed away the time-honored plate of pasta in favor of a "paleo" approach to nutrition.
Read more: http://www.mensjournal.com/health-fitness/nutrition/paleos-latest-converts-20130618#ixzz3KZ4EsZXq
Yes, everyone's different, so what works for one, might not work for another. Also, some may have a rough transition from one type of diet to another, for a variety of reasons.
I know what you mean about Harley. He's his own worst enemy.