It was 100 miles, not 100 km. I didn't feel the onset of any symptoms until the 70th mile.

It was not hot -- in fact, it was cold. The winds around the Golden Gate make it a perpetually brisk environment.

I ate all the food I had on the bike in the first 65 miles. At first, I couldn't bring myself to ask someone else for food. Later, I was on the bridge's 5-foot bike path and there was no way I was stopping on it.

My main concern is this: how can I tell the difference between normal, expected fatigue and an impending bonk? I wasn't having neurological symptoms until I got on the bridge and couldn't stop. When I first started feeling bad, it just felt like I was baked. I thought "Wow, I'm going slowly, but man, my legs are just so tired. No big deal. Let the others pass you."

- Warren