Don't hang up the cycling shoes!!!

I agree with the other posts. I think it was a combination of things. I think you probably over did it and didn't fill your body with what it needed. Electrolytes are a good thing to think about. My husband is big on getting the right "stuff" for your body and, after researching and trying different things, he gets Cytomax Lite. We get it in powder form and mix it into our sports bottles with water. You might want to look into that or something else. We like the taste. Not too sweet and no after taste. You should drink a sports bottle full every hour, probably more in extra heat and humidity ... even if you don't feel thirsty.

What you eat and drink before your ride is important too. You have to figure out what works for you and stick with it. I usually eat a banana and/or toast with peanut butter.

Also, your recovery is very important. We take Recoverite within 30 minutes of hard rides. It helps your muscles recover quicker, but also helps replace lost electrolytes along with some other things. I looked up some info on it and found something relating to stomach distress.

Unlike most recovery products that contain simple sugars, maltodextrin provides a large volume of easily digested and rapidly assimilated carbohydrate, vital for preventing stomach distress and promoting full, efficient restoration of muscle glycogen.

I know that headaches are a common symptom of dehydration, so you probably did dehydrate yourself on your ride. Also, when you push your body harder than its used to, it's going to want rest. It's very common to feel very sleepy after exerting yourself when you go past what you are used to. Your body is screaming for rest (literally sleep) so it can recover. I read in a book recently that said if it's possible, you should schedule in a nap after a hard ride.

If you want to do more crazy 20 mph rides like that (I'm totally jealous, by the way!), you might want to work on building up to it.

I live in California where it's rare to have a humid day. Yet, last summer we went through a crazy heat wave with a lot of humidity. Dh and I did our longest training ride for a century on our tandem in that sort of weather.... 110 when we finished I think. We were pouring water over our heads constantly to keep our bodies cool. That might help as well with the heat and humidity part of it.

I'm not sure I agree with the Ibuprofen idea. I took some before a long ride because the muscles in my back had been bothering me on long rides. I tried to cut it off at the pass. However, I ended up bonking on that ride and my husband thinks Ibuprofen might have been part of the reason. (Also pushing myself past my limits to keep up with my friends didn't help either!) I don't remember what he said about Ibuprofen, but he's read a lot about it because he "used" to take a ton of it and he tends to think it's not the best idea to have right before exerting yourself if you can help it.

Hope my thoughts are helpful. Keep riding your bike!!!