I usually have a piece of toast with peanut butter before a ride. I typically ride first thing in the morning, though. If it were afternoon or evening, it would depend on when I ate last and how long/hard I intended to ride. My husband can easily ride on nothing. Maybe not nothing "all day" and then ride, but nothing before a morning ride. But, yes, it sucks to get out there and realize you have zero energy all of a sudden.

I learned on my long and grueling climbing century, when the weather was not too bad, but hotter than expected (80's), that I need to "make myself" drink more. And I DID drink more, but apparently not enough. About half way through the ride, I wasn't feeling so great. Losing energy and my stomach wasn't feeling so great. I knew I needed to fuel, but the thought of eating or drinking anything at all was not appealing. I was probably dehydrated. If I had drank more to begin with, I might have avoided this.

Dh had warned me too, not because of the heat, because it was supposed to be in the 70's, but because of the higher elevation than I usually ride.

Anywho, lesson learned by both of us.