Originally Posted by
Bassmanbob
I thought I may be mini-bonking because I was riding harder and harder, yet going slower and slower for about four or five miles. But the more I think about it, I think it was just a low glucose level due to what happyscientist said. As soon as I turned the corner and headed west, I was fine (the wind was coming off the ocean from the east on this weekend's ride).
Or maybe you were just riding into a significant headwind.
Use your training rides to experiment with nutritional strategies. If you are riding at high-for-you intensity for >2hr, you need calories. The harder you are working, the more issues you might have digesting food. So sometimes "real food" is worse than gels or other "bike food" because it needs to be digested. Sometimes "real food" is better than "bike food" because it contains protein and usually some fiber, which is digested more slowly and stays with you longer. It will depend on your unique physiology and also your training state (the more you train, the less the intensity of your rides may be and therefore the less you may need to eat).
Once you figure out what kind of things you can successfully eat on the bike, then try to minimize what you eat during your training rides, see if you can train your body to metabolize fat a little more efficiently.
Don't be afraid of carbs on the bike though, unless you figure out through trial-and-error that they are detrimental for you. Carbs-on-the-bike if a different thing than carbs-off-the-bike.