CdCf

(All Imperial units in my post, for a change...)

I went for a ride today. 100 minutes and 25 miles.
About half an hour before the ride, I drank about 16 fl.oz. of tap water and another 12 of fruit juice (pineapple, orange, banana mix, no added sugar).

The temperature outside was around 55°F and the sky quite cloudy, almost overcast at times.
I didn't sweat much at all (I never do...) and I didn't feel excessively tired.

After the ride, I ate two vanilla/choc ice creams - this kind:


About 15 minutes later, I drank a 16 fl.oz. soft drink bottle (no caffeinated kind).

1-2 hours later, I gradually got a bad headache and felt hot, dizzy and nauseous, and my pulse shot up to between 100 and 125, from around 80-85 half an hour after the ride. My resting pulse is 55-60 normally, and maybe 65-70 in the evening following a long-ish ride during the day.

I drank some more fluids 4-5 hours after the ride (2-3 hours after the headache started), and now I feel pretty good again. Took some paracetamol too to take the edge off the headache.
My pulse is down to 60-65 and I'm cool again.

So, was this a clear case of dehydration?
Or something else?

Roody

Sounds like you got plenty of fluids (44 oz. in about 2 hours, by my calculation) but LOTS of sugar: fruit juice, soda, ice cream. Have you ever had your blood sugar checked?

CdCf

Yep, checked twice in the past 7 years. Nothing wrong with my blood sugar.

The total carbohydrate count for the stuff I listed is 140 g, over a period of 3 hours.
But it's not extreme, in my opinion. I always eat lots of sugar after any exercise.

Machka 

My guess ... it's not dehydration, it's something else. A 25 mile ride isn't that far, and it sounds like you drank enough for that.

The general guideline is one 750 ml (3 cup/ 26.4 oz) bottle of water or sports drink every 1 to 1.5 hours of riding. If you drank 28 oz before you went out and then another 16 oz when you got in, that should be fine. However, you might consider bringing a bottle with you when you ride.

As for food, though, you only mentioned two of those ice cream bars in the 7 hours after the ride. That's not enough. Those are too high in sugar to sustain you for that long a period of time. I would hope that you ate a real meal at some point in those 7 hours ... if you didn't, I've got a pretty good guess what brought on those symptoms.

And ... you might consider adding a bit of protein to your post-ride food. Too many simple sugars just aren't good.


One more thing ... are you lactose intolerant? If I ate two ice cream bars after a ride, I might have those symptoms too ... because I can't consume much lactose.

CdCf

Not lactose intolerant, nor allergic to anything as far as I can tell...
(I used to drink around a gallon of milk (0.5% fat) a day until very recently, when I decided to stop, for reasons not having to do with nutrition or health.
Never had any problems with that, and I'll probably take it up again later this year.
Plenty of good protein and slow carbs!)

I did eat more than that after the ride, though. About an hour after, I ate a can of white beans in tomatoes, plus a can of tuna another half hour later.
Couldn't really eat anything earlier than that after the ride, because I wasn't at home. I stopped at the local store to get some milk for my grandmother, so i ended up chatting with her for almost an hour...

I found a bottle that probably fits in my bottle cage. It has that shape, but I suppose bottle cages come in many different sizes, so I don't know if it fits mine.

The question is, if it wasn't dehydration, what then was it?
I spent an hour earlier trying to find info on dehydration and especially the symptoms, and it matched perfectly. Headache, dizzyness, nausea, high pulse...

And Machka, maybe 25 miles isn't far to you, but today's ride was the second longest I've ever done! I usually only ride 10-15...
Not only was it the second longest ride, it was also faster than I normally manage.

When I get my new saddle, I expect I'll be able to ride much farther, since my precious bits usually fall asleep after 10 miles as it is now. That prevents me from spending more than tens of seconds at a time in any kind of aerodynamic position...

operator

Sounds like you didn't eat enough, not that you didn't drink enough.

kf5nd

For that ride and temperature, personally I would only drink about 750 mL - 1000 mL of fluid, possibly even just plain water. You may be overhydrating, which would account for headache (brain swelling). Weigh yourself before and after the rides. You should not gain more than a kilo. If you do, stop drinking. If this doesn't help, see a doctor, you may have heart problems.

manual_overide

You didn't eat enough. Luckily you were at home when the bonk hit instead of out on your bike like me two weeks ago. I had only planned a 25-30 mile ride, but it turned into 45 instead because it was nice out Anyway, some peanut butter and a bottle of gatorade (and lots of water) lasted me until mile 40. I had exactly what you were experiencing. I knew it wasn't dehydration, because I've had that before too. This was different. I figured I must be bonking because I knew I didn't eat very much plus my tummy was telling my brain that eating my own legs might be a good idea. Anyway, after the ride was over I gave my tummy a plate full of barbeque and he forgot all about the whole leg idea

Make sure you eat enough good calories before you go burn them away on your bike next time.

Roody

I think you were just tired! Plain and normal tired. I bet if you try that same ride after a day or two of rest, you will find it a bit easier. One of the coolest things about cycling is how the rides get longer and faster as you go along. Just remember the principles of progressive training--make it a little harder each time!