View Full Version : Too many calories during long rides?

08-06-2006, 07:00 PM
So I've seen a number of tables estimating calories burned while cycling based on weight and speed... and run across estimates ranging from 30-50 calories per mile.

It seems like experience may be as good a guide for non-elite athletes as trying to be absolutely precise in estimating calories burned based on wind, grade of climb, etc... So here's my question:

Yesterday I rode 84 miles, my longest ride yet by about 50 miles :). (The length happened partially by accident). I was riding by myself, and didn't know how my body would react to that distance, so I was assiduous about refueling (as a runner, I know what bonking feels like and I wouldn't want it to happen to me alone, 20 miles from home, on a bike, in 85 degree weather). I was riding at a pretty brisk pace for me (averaged 16.5 miles, which really means 18-19 much of the time, except for some of those long, shallow hills where I was struggling to hold 13 riding into a headwind). Over the course of five hours on the bike, I consumed a total of 750 calories -- a clif bar, a luna bar, two bottles of sports drink and a bottle of vitamin water -- based on your experience, does this sound like a vaguely appropriate amount? It felt ok -- no bonking, but didn't feel like I was stuffing myself either. However, I'm not in the habit of eating while exercising (I can't eat anything more substantial than gel within hours of running), and this sounds to me like a recipe for gaining weight -- that's like, half a day's calories for me off the bike (I'm ~120 lbs)... Thoughts? Advice for fueling during long (for me?) rides?

08-07-2006, 04:37 AM
Liza ~ That sounds fine, and no, you will NOT gain weight eating that many calories on a ride of that length because you burned many more! If you're really concerned/interested, you might want to invest in a Polar Heart Rate Monitor, which can estimate your calories burned during your rides (based on your height, weight, and intensity as measured by your heart rate). I'm small (~105 lbs) so don't burn nearly as much as a larger person, but on a ride of that length (~5 hours), I would typically burn about 2000 calories! And my husband would burn more like 3000. So as you can see, a ride day like that is not your normal day at all, and your caloric intake can definitely be adjusted accordingly! You could actually eat quite a bit more and not have to worry about gaining weight on day like that, but if you were okay on that amount of fuel and didn't bonk, then you know your body best. I would need to eat more like 1000 calories for a ride like that.

Congratulations on your longest ride ever. It's a rare athlete who can increase by 50 miles in one chunk without suffering mightily, so consider yourself rather elite! :D


08-07-2006, 07:19 AM
Sounds like a *great* ride :-) :-)

You burned more calories than you took in, I would be pretty sure. (My problem is my insatiable appetite teh day *after* a long ride, when I can eat three rides' worth of calories... I drink a lot of water :-))

08-07-2006, 11:11 AM
I go by how many hours I'm riding, not how many miles.

From The 10 Biggest Mistakes Endurance Athletes Make

by Steve Born

Improper Amounts of Calories

Too many endurance athletes fuel their bodies under the premise, "If I burn 500-800 calories an hour, I must consume that much or I'll bonk." However, as Dr. Bill Misner says, "To suggest that fluids, sodium, and fuels-induced glycogen replenishment can happen at the same rate as it is spent during exercise is simply not true. Endurance exercise beyond 1-2 hours is a deficit spending entity, with proportionate return or replenishment always in arrears. The endurance exercise outcome is to postpone fatigue, not to replace all the fuel, fluids, and electrolytes lost during the event. It can't be done, though many of us have tried." In other words, your body can't replenish calories as fast at it expends them (ditto for fluids and electrolytes). Athletes who try to replace "calories out" with an equal amount of "calories in" usually suffer digestive maladies, with the inevitable poorer-than-expected outcome, and possibly the dreaded DNF ("Did Not Finish"). Body fat and glycogen stores easily fill the gap between energy output and fuel intake, so it's detrimental overkill to attempt calorie-for-calorie replacement.

Keep this in mind if you're doing ultra-endurance events, especially if you've had to "alter the game plan" and are unable to stick to your planned hourly calorie intake. For example, let's say you've been consuming an average of 280 calories an hour but the heat or other circumstances (such as climbing a very long hill) prevents you from maintaining that desired hourly average. DO NOT try to "make up lost ground" by consuming additional calories; it's not only unnecessary, it may very well cause a lot of stomach distress, which will hurt your performance. Remember, during periods where fuel consumption may be less than your original hourly plan, body fat stores will effectively fill in the gap, thus eliminating the need to overcompensate with calories.

Recommendation: Intake of 240-280 calories per hour, on average, is sufficient for most endurance athletes. Lighter weight athletes (<120-125 pounds) may need less, while heavier athletes (> 185-190 pounds) may need slightly more. Experiment in training to determine your specific requirements, using 240-280 calories/hour as a base to work from. If you fall behind on your average calorie intake, do not consume excess calories to bring your average back up.

08-07-2006, 05:47 PM
I read the other day that our bodies can only absorb one "carb" (I assume he meant one carbohydrate gram) per minute. So, if you're riding 100 minutes, don't ingest more than 100 grams, or 400 calories, of carbs, even though you may have burned about 1000 calories during that time.

08-08-2006, 03:54 AM
I second the suggestion to purchase a HRM that gives you calories used. You correctly assessed that calories used can change with terrain, head winds, etc.

Sounds like a great ride!

08-08-2006, 04:15 AM
I rode the MS150 this past weekend. Friday night I had a plate of salad/spaghetti and breadstick.

Sat morning I fried up a couple eggs and had toast plus a glass of a hot cocoa concoction/coffee.

I biked 100 miles on Sat, ate throughout the day a couple energy gels, a ham sandwhich, orange slice, some soda, a bottle or so of gatorade, cracker packs, a candy bar, a brat, banana, a big plate of pasta, salad, green beans that night and ice cream.

Sunday I biked 50, I had scrambled eggs/pancakes/hashbrowns for breakfast, nibbled a little on the ride, half a ham sandwich at the checkpoint, candy bar, at then end they thankfully had chicken breast, baked potato and salad... I was getting really tired of carbs.

I did drink a little gatorade, a lot of water, and a can or two of pop during the rest of the day. And ate some other stuff.

I ended up gaining 3-4 pounds this weekend past my peak weight. I imagine that my body has retained a lot of garbage that may take a little while to flush out. It wasn't a flat ride, lots of rolling hills. Though we had a tail wind for much of both directions... yay!