Calories burned = confusion
 

I admit to being confused and feeling misled by the typical on-line calorie counting calculators for bicycling. The built-in calorie calculator for my Garmin Edge 200 GPS doesn't seem to be any better and is on the "low" end of the array of estimates. Based on my riding (mostly bike club rides of 2-4 hours) at 16-17 mph averages with moderate climbing of 1,000 ft to 3,000 feet, the calculators suggest that I'm "burning" around 1,100 calories per hour for my height/weight/age. A three hour ride will be 3,100 to 3,500 calories burned depending on altitude climbed and average speed by the estimate of the Garmin Edge 200. I understand that these calculators don't encompass wind, drafting, and a few other factors that would impact the overall result. And, FWIW, I don't own a power meter that might give me a more reliable estimate of calories burned.

Here's the dilemma I encounter. By tracking what I eat (lots of on-line help for that) and what I burn from cycling (using the calculators), I should be losing a LOT of weight, on the order of 4-6 lbs a week. That's just not happening :notamused:! I know enough about nutrition to be aware that not all calories are equal (glycemic indexing, etc.), and that timing has an effect on blood sugar/insulin/glucogon levels, but I have made adjustments in what I consume...and when to mitigate the effects of what I eat in line with my activities.

So either the calorie calculators are estimating much too high for calories consumed or there are more factors involved than I am considering. I'm hoping that wiser/smarter/more experienced folks than I can enlighten me.

I use My Fitness Pal to determine my calorie budget. Even choosing sedentary, if I follow their guidelines, I will not lose weight. I have determined I have to have my goal set at lose 1.5 pounds per week in order to maintain my weight. I let MFP keep track of the calories I burn while biking but I don't eat back my daily rides. Even my longer weekend rides, I don't eat back all the calories. This is the only way I seem to lose weight. :rolleyes:
My guess is that my metabolism in the toilet from years of dieting. And the only way to really determine what my BMR is to undergo expensive testing. :notamused:

Calorie calculators, i.e. Garmin, are terrible. Compared to my power tap, the garmin is almost double in its estimate, i.e. way off.

Here's an estimate that will work better than all those calculators ...

Assume you're burning somewhere between 400 and 600 calories per hour.



** If you are doing a climbing ride where you'll be going up for an hour or more, you might possibly be burning 600 calories per hour.

** If you are riding really hard, it's possible you might be burning 600 calories per hour.

** If you are obese, there's a chance you might be burning 600 calories per hour.

However, if you're riding a relatively flat ride, and a reasonably comfortable pace, and you're somewhere within normal weight limits, chances are you're burning at the lower end ... maybe somewhere between 400 and 500 calories.


And if you're trying to lose weight, assume you're burning 400-500 calories per hour. Always assume you consume more than you think you are consuming, and burn less than you think you are burning.

In your case, I'd estimate that a three-hour ride burns about 1500 calories.


If you want to lose 4-6 lbs a week, you need to have a 14,000 to 21,000 calorie deficit each week. A deficit of 2000-3000 calories per day. That's a lot!!

That sounds way high for 16-17 mph rides. I'd be curious about what calculator, and the numbers that were input to get those results.

Here are links to a few of bicycling calorie calculators...

How Many Calories Do You Burn Cycling? | Bicycling Magazine

Calorie Calculator - MapMyRide

Calculate Calories Burned Biking

I'm guessing that these and similar calculators may all be based on some long-past algorithm that gets repeated without question as time goes on. My first-hand experience suggests that Machka's idea of 400-500 calories an hour is closer to "reality" (whatever that is!). In my own case as a Clydesdale rider (6'5", 215 lbs), keeping up with the faster group on my club rides is a serious workout, so I believe that 500 calories per hour would be a good working estimate. Maybe another good option is to use the number from the Garmin edge but reduce by 60%.

Thanks for the comments and ideas!

Those are not the best calculators for a number of reasons, and they are all too basic to give anything accurate for actual rides. Height is not a large factor, and I think it's a roundabout effort to get a body mass index figure. Body mass index can also be deceptive because higher mass with lower body fat will burn far more calories than with higher body fat percentage. The ride you are calculating is also problematic because you are putting in one set of figures for a ride that is likely composed of distinctly different types of terrain. You can get a reasonable estimate by dividing the ride into climbing, descending and flat sections and then adding the results for total calories. The fact that you are 6'5" and 215 to me implies that you are fairly lean, and maybe 600-700 per hour might not be that far off. Try Bike Calculator and see what you come up with.

This one Bike Calculator makes it easier. Using your info with some guesses on the segments (3hrs total - 3000' climb @ 5%, 3000' descent @ -5%, remaining 110 minutes on the flats @ 18mph) I came up with around 700 calories per hour average.

Listen, I am a pretty fit but too fat cyclist weighing close to 200 lbs. On a flat course with no wind I can ride 24 miles in an hour. At that pace I am absolutely exhausted at the end onpf the hour and have burned almost exactly 1000 calories.

Burning 2000 calories in three hours is very hard. The algorithms used by most HR monitors are hopeless, and hopelessly overstated. For most purposes, you may as well estimate 25 calories per mile. You won't be far out and it'll save you a lot of expense on a powermeter.

I'm 175lbs. Ride 35-40 miles every other day. Somewhat rolling terrain. Avg. 16-17 mph. I figure 30 calories per mile. Just a rough guess as I'm not trying to lose or gain weight.

Some of the newer devices/websites are more accurate. Strava figures calories from equations of motion and seems close to me. When I import my Garmin 800 ride data into TrainingPeaks, it seems to do a decent job of calorie estimation. My wife and I did a 50 mile, 2000' climbing ride at endurance pace, 3:20, on our tandem today. Strava said 1900 calories for both of us, while TrainingPeaks, which I believe uses HR, said 1100 for me, the captain, leaving 800 for my stoker. That's probably about right. Our team weight is 287 lbs. and I figure the bike weighs about 47 lbs. all up with gear and water. Strava estimated 156 watts average power for the whole bike.

That seem reasonable to you PM people?

My road bike has the PT and I recently got a Garmin that I use for power data and I also take it on my mtn bike which doesn't have power. Riding my mtn bike on flat recovery rides, I would estimate that Garmin produces numbers that are somewhere in the neighborhood of reporting 120%-160% of the calories that my PT would show. Just the other day I went out for an easy two hour spin on the mtn bike and the Garmin estimated ~1000 Cal. More likely around 800 Cal. Don't trust my numbers for extreme accuracy; what I do know is that the Garmin overestimates considerably.

I've been using Strava for my calorie estimation. For a flat road ride with no wind over about 12 miles it comes up at 600 ish for me (avg speed of about 16 mph).

Riding the mtn bike, Strava estimates mine by about half of what my friends with HR monitors get for the same ride, and I'm by far the biggest one at 6'5" and 283 lbs.

I'm thinking the Strava estimate is fairly close for me, but I'll probably never know for sure.

My first-hand experience suggests the same thing. :)

I think I understand your problem and I might be able to shine a little light on what is happening.

Just like smoking, or drinking, or any other addictive behavior over-eating is also a "disorder".... (or addiction). I get the idea you're looking for some logical way or means of losing weight.... without dealing with your eating disorder. Best of luck with that... but I don't think it will happen.

Never in my entire long life have I ever even once heard anyone say that their car just isn't burning fuel. I never hear that... because it never happens. Our bodies are not much different than machines when it comes to burning fuel. If we eat less than we burn... we lose weight, PERIOD. People prove that correct everyday by starving to death. Not that they WANT to starve. there just isn't enough food/fuel to keep their bodies alive. They get very thin, then they die.

It doesn't take so much food to stay alive. At six foot tall I can remain pretty darn happy and healthy on 1200 calories a day. Of course... at 1200 calories I lose weight. If I exercise... I lose a little more weight faster.

If I eat 2400 calories because... heck I rode a fast hard 30 miles today. I don't lose weight. I may not lose even an once. No matter how much my food addicted brain tells me I should.

It is good to track miles and such. But I would not plan on riding off the pounds so much. If you're not losing weight it isn't your Garmin's fault. You are just eating too much.

Bike Calculator seems to be a more realistic estimate of calories burned than the others that I have found. Thank you for that link.

The whole point of my original post was not to focus on losing weight, but rather to point out the poor estimates of calories burned using some of the readily "findable" calorie calculators, including that on the Garmin Edge 200. Losing weight is not a mystery if you consume fewer calories than you burn. As one poster correctly pointed out, just about any diet plan will work if you follow it.

Garmin has been one of the worst over the past ... many years. But yes, most calculators over-estimate the amount burned. It makes people feel better to think that they don't have to do much to burn a lot of calories .... until they realise they aren't losing weight.

I use a heart rate monitor that has my weight and age programmed in and it gives me a seriously accurate measure of calories burned.

I find that if I use Myfitnesspal.com and plug in 12-14 mph for my rides (even though I typically ride faster), that I get reasonable correlation between body weight changes and exercise. 1100 calories per hour is off the charts... I think 400-500 is a lot more realistic for most cyclists. And I don't think you can just assume that you will burn this over the course of a very long ride as you don't maintain the same intensity. I doubt touring cyclists riding ten hours per day consume 5K calories above their baseline metabolism.

- Mark

I very much doubt it. The algorithms used cannot take account of different circumstances and are an approximation at best.

My observation is that my Garmin 500 will overestimate calories by a factor of 1.5-2.0. Seems to be worse in high variability rides like crits and CX races, where your HR may stay elevated during recovery periods even though you aren't doing any actual work.

I agree. I've found that I need to multiply the calories displayed on my Polar HRM by 0.65 - 0.70 to get something realistic. 0.65 works for moderate efforts and 0.70 for interval sessions. YMMV.

Putting out a steady 200W will burn about 700 cal/hour, so 500 cal/hour would be about 140W. I've averaged 160W for 7 hours doing a double-metric century, which comes out to be almost 5,000 cal. And I'm not exactly fast - there are a lot of riders who are faster and put out more power (burn more calories) than me for longer times.

10 hours at a 140W average power is easy to imagine, even for 10 hours of riding.

A typical 75-mile day for a bicycle tourist and doing double-metic centuries aren't really comparable. Yes, you can have a 5K calorie day if you work hard enough, but most riders aren't remotely fit enough to do it. In the TDF, the riders consume about 4-5K during the race proper. We can nitpick the numbers, but the point is that most of the sources seem to dramatically overestimate calories burned in everyday normal riding. If you're assuming 800+/hr and not racing, you're not being realistic. And if you eat these calories every night assuming you'll burn them off, you'll gain weight.

- Mark