I am somewhat new to biking, but not to fitness (can bench my bodyweight 10 times, can do over 10 dead hang--NOT kipping--pull-ups, etc.). I have a 30 minute ride that's a great, albeit short, workout/ride. I basically ride up and down a few modest hills before hitting a true one mile hill. I get to the end of it and return when my heartrate will stay at 85% max for several minutes, and I've progressed to a fair level of fitness with a one minute heartrate recovery that's slightly greater than 21.

I've done this ride many, many times and I've never felt any need or cravings for food after this ride. Recently, I've doubled the ride to a one-hour ride with one hill that's even longer and steeper which gets my heartrate to 90% for several minutes. Often, but not always, my body seems to crave food! I also feel somewhat fatigued with almost pre-flu like symptoms. I'm a lean individual (5'-10" and 160#) and I just don't normally "crave" or should I write "CRAVE(!!!)" food.

Does anyone else ever feel this way? Might it have something to do with pre-ride nutrition (note: I don't purposefully eat prior to the ride, but I'm definitely not riding while hungry). Might this go away with even more conditioning?

Your body is telling you it needs fuel. Give it some more.

You're burning a lot more of your glycogen stores by doing the double length ride vs the standard 30 min ride. It also sounds like a more intense ride as well. Yes, you should probably indulge yourself with some carbs pre and post ride.

It is very important that you eat shortly after your ride. Your food should be heating up in the microwave while you are in the shower. Eating within 30 minutes of the end of your ride will help you recover more quickly, and reduce soreness.

Sounds like hypoglycemia. Listen to your body. Better yet, don't let yourself get into that condition, as you do tend to overeat. About what Doctor Morbius just said.

The rules for cycling I used to teach in my Safe Cycling classes:
1) drink before you're thirsty
2) eat before you're hungry
3) rest before you're tired

At one hour, the OP isn't doing enough to deplete the glycogen stores in the muscles and liver. Unless he hasn't eaten anything at all in the day before the ride.

I am interested to know what sort of rehydration is happening on these rides.

I'm usually always hungry after riding...and I listen to my body.

Many of us with diabetes can move into the hypoglycemic range very quickly, though I'm sure you are right for those with a normal metabolism.

I don't see where he says he is diabetic. But it might be worth his while to check his blood glucose levels with a doctor.

I'm no expert, but I've read several places that strenuous exercise can consume all of your glycogen reserves in an hour. I know I started experiencing the symptoms once my rides got up around an hour.

Now I drink Gatorade for all rides over an hour. The sugars in it prevent hypoglycemia. As long as I have some sugar water I can ride as long as I want to.

Your over thinking it. If your hungry, just eat.

I regularly run or bike...typically 5 or 6 days a week, typically for between 1 hour to 1:20 each time I go out. For the most part, its in the morning, having not eaten since the previous night.

Shortly after I get done, I'm a ravenous pig...its so bad, I have to snack on something while I make my breakfast! According to all the calorie counters I've checked, I'm burning over 1k calories a workout. I'm not worried about it.

One hour is enough to deplete most of the glycogen stores if the exercise intensity is high enough.

Read post number one. The OP, in my opinion, is not sustaining a high intensity for long enough for this to happen.

So ... you're riding a minimum speed of 50 km/hour during your 1-hour workout? Good job! Have you considered racing?


Or ... if you're not ...

Then, no. You're not burning 1000 cal/hour. Those calorie counters notoriously over-estimate the number of calories burned. Some quite significantly.

We burn approx. 100 cal for every 5 km we cover. If you ride 20 km/h, you burn 400 cal per hour. If you ride 25 km/h, you burn 500 cal per hour.


A slight variation to that might be if you spent the whole hour climbing. So if you went out and climbed for 1 hour and then cycled back down for the 20 min ... you might burn a little bit ore than 100 cal for every 5 km, on the way up.

How long before the ride do you eat?

In other words ... if you ride at 6 pm, do you eat at lunchtime?

If it is a while, you could simply need a quick bite to eat before you go out ... like maybe a small granola bar or banana.

Not sure where you're getting that 100cal/5km rule...but according to this, I burn over 1k. See "bicycling, 16-19mph" (I weigh right around 185).

The old thinking was 40 cal/mile. That would work out to 125 cal/5 km.

But they're rethinking that, and dropping it to 30 cal/mile, which works out to about 94 cal/5 km. Some even say as low as 25 cal/mile which is only about 78 cal/5 km.

But the 100 cal/5 km is reasonably ballpark.


And links like the one you've linked to ... notoriously over-estimated like most of them.

I would love to see a source for this ballpark estimate, as well as reasoning that these numbers don't vary wildly once speed and weight of the rider are taken into account

Do a Google search on the 40 cal/mile estimate.

And whether you base it on 40 cal/mile or 30 cal/mile or 100 cal/5 km ... speed is factored in.

In the old imperial system, if you cycle 15 miles/hour, at 30 cal/mile you will burn 450 cal in an hour. But if you pick up the pace and average 20 miles/hour, you'll burn 600 cal in that hour.


As for weight ... not really that much of a factor. Maybe if you weighed in at 300 lb and could keep up an average speed of 20 miles/hour .... maybe ...


Go post this topic in the Training and Nutrition forum and see what sorts of responses you get.

Only the incinerator can burn 1000 cals per hour. At 5'10" & 160 yo is skinny, not much body reserves to rely on - eat something. A banana covered in peanut butter before your ride and see how that goes. Still hungry when home then feed muscles some protein - Whey protein shake is good. Try it and see, let us know how it feels after that.

Drag isn't linear. As you increase speed, you increase the effect of air resistance, so the calories burned isn't a straight line.

When the OP says this:

... it sounds like it could be hypoglycemia. What do you think is causing his symptoms?

It could be hypoglycemia.
It could be that the OP is dieting ... but hasn't told us that.
It could be that the OP just didn't eat for several hours before the ride.

Thanks for all of the replies. I come from a weightlifting background, so pre and post workout nutrition is very familiar with me. I always make sure that I eat something before a ride. I always eat something (usually 40g or more of protein and typically at least that many carbs, too). As for hydration, I have water with me, and I drink from time to time drinking about a pint for my 60 minute ride.

I think that I am borderline hypoglycemic. I have a blood glucose meter but I've only used it once. I was cutting grass and weedeating and I felt marginally "shakey." The meter said my blood glucose was 116. I have felt much shakier before, but NEVER AFTER A RIDE! I'm not shakey after a ride--I'm just craving food but it's a craving that seems almost impossible to satisfy AND I feel somewhat "under the weather." And it doesn't happen after every ride either.

I'm going to pay CLOSER attention to pre-ride nutrition. Perhaps I wasn't eating as much as I thought and then see if I can find a pattern.

EDIT: Just came back from my short (30 min) ride, and as always felt fine (not hungry with no flu-like symptoms) and took my blood glucose reading just for a benchmark if nothing else and it was 68!