"bonking" question

[goldfinch]

Today I did an organized 50k ride. It went just fine, other than the fact I got a flat. But the SAG showed up while I was just starting to take off the wheel and they changed out the tube for me. Anyway, the ride had a long uphill at the start (category 5) and then was mostly flat, with a few minor hills. I felt great at the end and could have gone twice as far.

Initially I had planned to ride the 100k route but the ride was poorly supported and there were no porta potties supplied. I did not want a 65 mile ride with no clear potty stop so I did the short ride.

I was left at the end of the day feeling really energetic so I volunteered to take my hybrid bike to the grocery store for milk. The store is about three and a half miles away, mostly uphill, with an 8% grade about half way and total elevation increase of about 360 feet. I started riding and felt that I was a bit slow and actually wondered if my rear tire was low and stopped to check. Nope. Everything fine. I went up the 8% grade hill and was going slower and slower, feeling really whacked out. Nearing the top of the steepest grade I was feeling very jittery, like a "sugar low" but had no nutrition with me, after all this was a short ride to the grocery. The hill continued up for the final mile to the store and I was pouring sweat even though it is only in the high 60s out, and feeling like I would barely make it to the store. I got to the store and almost dropped my bike chaining it up. I staggered to the milk section, pulled out the milk and dropped it on the floor. The store was nice, I didn't have to pay for it. I went and bought a doughnut, not thinking clearly enough to know what to get and the case was right there. I ate the doughnut outside, waited a bit for the sugar to catch up, and rode/coasted to the motorhome. It took me a good hour and a half and some more food after I got back to feel mostly normal.

So, what do you folks think happened? I always think of bonking as running out of energy on a very long ride, not on a very short ride. After the morning ride I had a big lunch of burritos, chips, and salsa provided by the ride organizers. It was too much food so I skipped supper. I was going to have a small snack after I went to the grocery store.

[goldfinch]

Hmm. Could just be bonking. But have you had glucose levels checked lately?

My fasting glucose is fine. At least it was at my last doctors appointment in November. My spouse is type 1, I'll check a few times using his kit.

[zoom-zoom]

My fasting glucose is fine. At least it was at my last doctors appointment in November. My spouse is type 1, I'll check a few times using his kit.

That's not a bad idea, though maybe skipping supper was key. I have bonked on 5 mile runs when I've experimented to see just how low I can go with net carbs. Turns out I can run/bike a moderate amount on 100-150 net carbs/day. The time I bonked 4 miles into a run was when I went <50 for a few days. I'd imagine that going too low on general calories would have a similar effect.

[jessmarimba]

This happens to me a LOT. I'll be fine riding or running, and halfway home I'll feel like I'm going to pass out driving. Or I'll stop somewhere on the way home and nearly pass out walking around somewhere.

Is there such thing as a "delayed bonk" ? I always just chalked it up as a natural reaction to lots of exercising but I guess maybe it isn't. It hasn't happened so much lately but I've also learned that grabbing a soda on the way home can keep it at bay, which isn't really a healthy solution either.

[tulip]

Did you eat and drink during the 50k ride?

[goldfinch]

Did you eat and drink during the 50k ride?

One half of a cliff bar and drank only water. On a short ride like that I usually eat very little, if anything. But, I also ate only an apple and cheese for breakfast. So I might have under did the nutrition for the ride.

This morning my blood sugar is completely normal.

[zoom-zoom]

One half of a cliff bar and drank only water. On a short ride like that I usually eat very little, if anything. But, I also ate only an apple and cheese for breakfast. So I might have under did the nutrition for the ride.

And no dinner...? I think I know your problem -- eat more. Unless you're trying to lose weight you should probably be eating closer to 1500-2000 calories to fuel your activity level. It doesn't look like you had even close to half that.

[Catrin]

I am prone to hypoglycemia if I don't fuel before and during a ride - and sometimes this has happened on very short rides if I haven't eaten in the preceding few hours. Your experience sounds familiar, I think Zoom is right - you need more food. I know what would happen to me if I did that kind of ride on a small breakfast and little food during - but of course all of our bodies are different...

[goldfinch]

OK, I think I agree that I had a terrible food management day. Too little breakfast. Bad high calorie lunch. No food again for six hours when I did the big hill to the store. And then I ate a doughnut (bad! but did get that blood sugar up!) and supper to compensate after the hypoglycemia episode. My total calories for the day ended up at about 2200, which is too much and resulted from lazy planning.

[Jiffer]

I agree. An apple and cheese before a 30+ mile ride, especially if you were riding with any sort of intensity, is probably not enough. You don't want to over do your food intake, either, because then your body is using it's energy to digest and not help you ride well, so you have to find the right balance of carbs and protein and the right ones that work for you. Whey protein is a great pre-ride fuel, as well as post ride recovery. Speaking of recovery, you should be getting carbs and protein within 30 minutes of a ride. And the more long or intense the ride, the more real food within the four hour window.

Also, during the ride, anything longer than an hour, you should be having electrolytes. Even if it's less than an hour but hot outside or a high intensity ride, you should also be getting electrolytes.

You may been dehydrated. I don't know that you need more than a cliff bar "during" a 30-ish mile ride, but pre-ride fuel and post ride recovery are important.