RadS

Sport is supposed to make you feel energetic, right? That's not the case with me.

I'm a 25 y.o. male, BMI is in normal range, I've been cycling regularly for 6 years. So far I've cycled 2500km this year and two of my personal achievements this year are cycling 190km in a single day and 100km at 27kmph average (on a hybrid bike). So I think I'm fit enough.

Yet, for some reason, after most bike rides I feel tired and sleepy and have a slight headache. This lasts for a few hours. Basically, I need to assume that cycling in the morning will leave me unproductive until late afternoon

Most of my rides are 2-3h at as high a pace as I can sustain for that long, usually averaging 70-80% HRmax. I try to drink one 700ml bottle per hour (iso tabs or homemade iso drink). On rides longer than 1h, I'd usually eat a 200-300kcal snack each hour after the first one. I drink about two glasses of water and eat some bread/fruit/yogurt after each ride.

I found that this effect is less noticeable and burdensome:

• after light-pace, short rides (1h at HR zone 1-2)
• when I stick to my 700ml/hour iso drink plan (as opposed to taking water only or underestimating how long the ride will take). However, drinking this amount doesn't guarantee feeling well after the ride, it just reduces negative effects.

Do you have any advice or ideas how to reduce this effect? What am I doing wrong?

Carbonfiberboy 

Experiment. My guess is low blood sugar. A thesis might be that you are eating relatively high G.I. foods and then have a blood sugar crash after the ride. Try eating less during the ride and more after. At the pace you quote, you probably don't need to eat at all on a 2 hour ride. After a 2 hour ride, try eating small amounts of carbs every ~15 minutes. Say you took a bagel and put a good bit of cream cheese on it, then ate the bagel gradually over an hour post-ride. Then have a hunk of cheese and an oz. of walnuts to smooth things out. Try that, report back.

I don't need to eat or drink anything on a 2 hour ride unless it's a pretty warm day. Weigh yourself naked immediately before and after the ride. You should weigh about the same, maybe a little less after the ride because of lost glycogen and associated water. If you weigh more, you're eating and drinking too much. If you weigh a lot less, say 2 lbs. after a 2 hour ride, drink more. Try that, too.

Don't measure your effort by max HR. That's unreliable. Instead take a test and measure your effort off lactate threshold heart rate (LTHR):
CTS Field Test Instructions and Training Intensity Calculations - CTS

A good training objective is to control blood sugar better by increasing fat burning ability. A very good way to do that is to ride for 2 hours or so while eating nothing. That carries over into your daily life, reducing hunger between meals. By eating too much carbs, too frequently, you may have overstimulated your pancreas, giving you a mild case of hypoglycemia.

alsek

Pay attention to other things going on in your life - perhaps stress, lack of sleep, overworking, or other issues can also lead to fatigue in addition to cycling.

Cyclist0108

Dehydration?

Drink during the ride, and triple your water intake. See what happens.

elcruxio

Neither of these things really happen. You don't spike in either insulin or blood glucose when eating during exercise. Insulin secretion goes down by 40-60% when exercising and insulin sensitivity is drastically increased. Combine that with the fact that you can only absorb ~60 grams of carbs an hour and it soon becomes impossible to spike blood glucose during exercise.
Even pure fructose doesn't spike blood sugar during exercise.
I've also never heard of the possibility of overstimulating the pancreas since it's a reactive organ and the reaction stimuli is the current blood clucose level. After a good level is reached, the beta cells stop secreting insulin and considering human insulin has a half life of only a few minutes, it's very unlikely any drastics changes are allowed to happen. That is of course that we're talking about your average healthy person. If one has a disorder of hypoglycemia, then the situation changes and a doctor should be consulted.

Carbonfiberboy 

Except that I had this exact thing happen, which is the reason I made this post. A visit to the doctor and I failed my glucose tolerance test. Since then, I've been much more careful about my carb intake and also much more careful about stimulating fat burning both on and off the bike. I still get the exact response of this poster if I screw it up. And worse, all the way to sweating and hyperventilating. It's permanent damage and not to be poo-pooed.

My admonition about not eating on the bike is to improve fat burning, which will make the OP less hungry in civilian life, reduce the necessity to eat a lot of carbs after the ride and help get rid of that blood sugar drop after riding..

I screwed myself up by going on a fat diet - very low fat which meant as a vegetarian, very high carbs. I never had a problem with blood sugar before going on this stupid diet. You mean that neither of these things has happened to you.

elcruxio

So many questions...
Failed the glucose tolerance test how? Were you having a high blood glucose or low? And how was the test performed? Also, why is that given to anyone in a normal checkup is really weird. Did they do a fasting blood glucose test first?

Also considering you ate a high carb diet for a while, you may gotten a chronic high blood sugar. After you've been high for a while, when you come back down to normal levels you're going to have the symptoms of hypoglycemia.

And one option is just that something triggered a hypoglycemia disorder which would have started in any case at some point. It does happen. But you average healthy person doesn't get that from eating carbs. If something, they can get type 2 diabetes, where depending on the type of type 2, one symptom actually is having hypoglycemias.

gregf83 

I don't know about the headache but you're supposed to be sleepy after a hard 3 hr ride particularly when you don't do them very often. A short nap should help as would more riding and increased fitness.

Weighing yourself before and after the ride is good advice to determine if you're dehydrated.

Carbonfiberboy 

My doctor ordered a fasting glucose tolerance test when I reported in with my symptoms. I don't remember the numbers, but the message from the diabetes doc was that my test was abnormal and that I should cut back on carbs and increase fat and protein in my diet. He said I was in the range of being pre-diabetic. I immediately incorporated those changes in my diet.

I doubt that it would have happened anyway. I'd never had a blood sugar problem and wasn't overweight or sedentary. And this was back before I started serious cycling, so maybe 25 years ago. Cycling has helped, particularly working with Chapple's principles for improving fat burning, but the base problem is still there. I have to be careful. A favorite afternoon snack is now an ounce of walnuts or a jigger of virgin olive oil or a piece of cheese, rather than toast and jam.

If one experiences the OP's lethargy symptoms on a ride, the advice is to eat and the best thing is high G.I. carbs. As you say, that works great on a ride, but it's not good advice if one is experiencing blood sugar swings off the bike, which IMO is what the OP is experiencing. It's not normal for me or anyone I ride with to experience lethargy after a ride. OTOH I don't feel like going dancing either, just a little normal tiredness.

Rowan

OP, you are dehydrated. Simple as that. Your clue is in your paragraph in your first post about how, when you drink the 700ml/hour, your headache is mitigated.

As a by the by, I feel sleepy and get headaches if I am dehydrated after a ride.

You need to experiment a little more with the amount of fluids you drink combined with the electrolytes. You also need to maybe reduce your riding intensity a little so that you don't forget to drink or put it off until it is too late.

chaadster

Yeah, I don't think being tired after a hard 3hr ride is weird, either. The headache sounds like a classic heat exhaustion symption; are these hot weather rides?

Try drinking more, and see if that helps.

elcruxio

Was away for the weekend and did a hard 3 hour ride with friends and actually had the same symptoms OP had. Ran out of water and carbs but didn't drop my blood glucose (I know since I have a monitor and keep a pretty good track when riding) and my main suspects were mild glycogen depletion since on the way home after the ride I had hardly any strength left in my legs and also a big factor was that my shoulders were tight, which can cause tiredness and headaches and the issue was increased by cycling for a long time. I've noticed that if one's shoulders are tight, cycling is not usually the way to open them up due to the static position one is in. I don't however get tight shoulders from cycling if the issue is not yet present.

RadS

Apologies for leaving your valuable responses without reply for so long! Thanks for all the input.

OK, I'll try:
1. Weighing myself before and after the ride to check for dehydration
2. Increasing fluid intake
3. Increasing electrolyte intake

Will report back after a few rides.

I'm not sure if it's relevant, but used to avoid high GI carbs during my attempts at weight loss in previous years. I only started eating high GI foods when I got more into cycling, under the assumption that I need to eat lots of easily digestible carbs before and during longer rides.


I saw my GP the other day and he recommended to try the following:
1. Blood tests (incl. glucose, potassium, magnesium, sodium)
2. Supplementation with potassium and magnesium
3. Checking/increasing electrolyte intake during rides
4. Checking riding position
5. Checking blood pressure after rides
6. Just taking a rest for some time

Regarding #6, I wonder if the increase in cycling intensity this year could be a factor. I cycled only ~1500 km per year over the past 5 years, but this year I'm already at 3500km, doing intervals fairly regularly, increased average speed on a 100km ride by ~10%, etc.

fantom1 

Honestly it sounds like a lack of base fitness. Sure, the body can do a lot if you are mentally determined, but normally you pay for it afterwards.

2500km /155 days= 16.13km/day. Not exactly that much.

It sounds like you might be doing a long, hard ride once or twice a week, and doing nothing on the other days. That's not a good way to build up base fitness. Do you find an increased heartrate/nervous feeling and poor sleep after these rides (and especially right after you eat dinner)? If so, that's classic over-training.

Maybe you are paying too much attention to stats and body measuring computers than to what your actual body is telling you? People have forgotten to listen to their body and end up training worse because of it.

Or it could just be that you aren't eating enough (on or off the bike), or perhaps you are too thin (though that doesn't sound like the case), or trying to lose weight too quickly. Actually losing weight too quickly will lead to symptoms like you are describing. If you are too thin or have an eating issue (common in cyclists), you will end up feeling extremely tired after rides.

Stormsedge

I agree...if you are drinking 700ml/24oz every hour, you're getting behind the pace your body uses the fluids. I tend to drink that same amount every hour, but I drink 8oz every twenty minutes whether I am thirsty or not...starting with the first twenty minute mark. I drink 8-12oz before taking off, so with two 24oz bottles I'm good for two hours and twenty minutes on the bike without support. Experiment with electrolyte drinks to find one you like/tolerate. Personally, I keep one bottle plain water and the other with Nunn's tabs in it.

Carbonfiberboy 

Prescribing a specific water intake isn't a particularly good idea. Riders and conditions vary. I've used anywhere between 1/4 bottle and 1 liter/hour. I ride with a guy who will commonly complete a 3-4 hour moderately hilly summer ride, averaging ~18, drink only 1/2 bottle the whole ride, and still be going strong. Better is to look at physiological signs:

Huh, I haven't peed in 3 hours and can't pee now. I wonder why that is.
Wow, I have to stop and pee every hour. Why is that?
Huh, I'm sitting down and my resting HR is still 120. Weird.
Huh, I stopped sweating an hour ago but it's hot out. I wonder why that is.

Without a tell, you don't know what your hydration status is. Drinking large quantities of water without thirst is not a good idea. I've done 200k-400k rides in conditions varying between 33° rain and 104° heat. Water consumption needs to vary a lot even for one person, depending on conditions.

Stormsedge

Noted. What I meant is "this works for me" and "do something different if what you are doing doesn't work". I'd anticipate anyone reading forum inputs to use common sense and select ideas based upon knowing themselves and their equipment. Some opinions may vary. 👍🏻

TexMac

Funny same thing happened this past weekend. 3hr hard group ride in 90deg heat, I changed my snack from Clif bar to the Gatorade energy bar. Big mistake, by the time I was getting home, I felt weak and horrible like I was going to fait. A day later, still have a headache.