Originally Posted by
chasm54
And to me, too. Yes, I think the problem here is less how much you ate on the ride - a 250 kcal shortfall wouldn't normally be that significant - but the fact that you were energy-depleted at the start, because of the 1100 kcal/day. You can crash diet, and you can undereat when on the bike, but you can't do both and expect it not to affect your stamina.
Well I'd already planned for it, and honestly, it caught me by surprise. I pulled of a 30 mile ride while only consuming
800/day earlier in the spring, and was OK afterward aside from some very mild nausea due to dehydration. Hilly limestone in Iowa, but I managed to push through it. And last week it was rather windy, not a cloud in the sky, and 90 degrees - 30 miles of mixed terrain with no problem and no additional calories. The week before that was a tough 90 degree hilly gravel ride. More on it in a second.
Originally Posted by
sstorkel
Sounds like a textbook bonk to me! Lots of people get a little tired and call that a bonk. In my experience, a true bonk makes you feel like you don't have the energy to stay on the bike and coast, let alone turn the pedals over. The nasty thing about a bonk is that it's difficult to recover from it if you stay on the bike: the body can only absorb 250-300/calories of energy per hour so even a moderate pace will have you burning calories almost as soon as you consume them. When I bonked while riding down the Pacific coast, the only way I could recover was to take a long lunch where I literally sat on the beach and did nothing. Even after that, I could feel that my energy levels were still somewhat depleted.
The standard recommendation is to consume around 250 calories/hr while riding. 4x250 = 1000 calories, so it's not surprising you came up short. Especially given how little you're eating these days! I'm a big fan of low-calories diets, but at 175lbs I don't think I could survive on 1100 calories/day. 1400-1500 calories/day (net) is about as low as I can go before I start to feel lethargic.
After more thought, it must have been. My last bonk, all I wanted to do was lay down and go to sleep, and I couldn't stand up. No amount of food that I had to force into my mouth could correct it, after 2 hours I finally made it back.
This time, though, I do realize my mistake. It was mis-judging the amount of energy exerted over the time. My longest ride prior to this, time-wise, was about 2.5 hours and I had no problem pulling it off. Yet they were later in the day, hence more of a base for intake before.
My baseline was too low before I started, the deficit had started before I could get a chance to replenish it. Lesson learned, and don't mis-judge mother nature, either.