bigbones73

This may seem like a simple question but do Clydesdales/Athenas burn more calories when biking than "normal" size bikers? When I plug in the miles and the time it took me into an exercise tracker, it tells me the calories burned. It just seems logical to me that I am working twice as hard to move my big body down the road as a lightweight biker. Is there a formula that takes our weight into account?

Mark Stone

There's too many variables to think about when trying to figure out how many calories are burned during bicycling. We can get a rough estimate with experience, but to come up with a bullet-proof figure is unrealistic. Style of riding, speed, type of bicycle, tire pressure, hill flat or downhill, when you ate last, what you ate last, wind direction and speed, and several other variables play in. However, given the same circumstances and same riding speed, I would have to agree with you that a heavier rider would burn more calories because he or she is simply moving more weight. However, a thinner cyclist is able to travel faster and therefore may burn the same amount of calories during a given period of time, whereas a heavier person would burn more calories over the same distance (by staying on the bike longer). It can get complicated, but I think you're right.

sstorkel

Using a power meter is the best way to know how many calories you're burning. Estimates from websites and HR meters are often off by 1.5-2X. Lots of people seem to think the Kreuzotter equations give a decent approximation of calories burned. Just keep in mind that the real world isn't nearly as well-defined as their web form makes it out to be...

bigbones73

That is quite the equation. Traditionally, I have not been a calorie counter but I have been reading some articles which piqued my interest. I have been using Spark People to log my miles. Today I rode my bike 8 miles and according the their formula, I burned 799 calories. It just seemed like I had worked awfully hard for such a minimal calorie count. I'm happy with my bike riding gains and as I said, I'm not really overly concerned about the calorie thing but it just seemed that maybe Clydes should get some type of bonus.

Shellyrides

If you compare bike riding to other work outs we get huge burns compared to others! And yes the bigger you are the more you burn. At my weight I burn more fuel then some one at a standard weight just sitting on a couch. Put us on a bike and we really torch the calories.

Mark Stone

+1 to that. Exercise that is similar to bicycling changes our entire body from the inside, systemic changes. Our hearts are stronger, our circulatory systems are cleaner and stronger, our lungs are much more efficient. We think more clearly and carry a better outlook. With a regular aerobic program, enzymes proliferate in our muscles that continue to "burn" fat even when we are at rest. Our bodies have strengthened immune systems and heal from injuries faster. We not only lose weight, we become healthier. Cyclists as a whole have lower rates of heart disease, cancer, diabetes and alzheimers. Skin quality is improved. Sleep quality improves. We become more mobile. If people are primarily concerned about their calorie expenditure, that is fine; but they may be surprised down the road by the most important changes when we bicycle.

krobinson103

I'd have to disagree on this count. If I ride 90 miles I might get 4-5000 calories on Endomondo. And thats optimistically high. I think its more in the ball park of 2-3000 calories. I weigh in at 85kg and ride at 25-33km/h for 5-6 hours at a time. I think you should be looking at at about 400 calories for 8 miles.

SeanBlader

CardioTrainer on my HTC Evo says on Sunday I did 16.6 miles which was relatively flat, in 77 minutes, averaging 12.9 mph, for a total burn of 906 calories. That was with a 10 minute stop halfway to see why my bike path was closed off with chicken wire. I wouldn't disagree 73 that you might have expended more effort than me for your 8 miles, but unless you were on a serious climb for those 8 miles, in a serious headwind, or were on a far more inefficient bike than my Allez, I can't imagine that you only burned 107 calories less than me but rode less than half the distance.

I definitely don't want to make light of the effort you expended, and I would agree that those bigger than me at 5'10"/200 would burn more, but at the same time I can't imagine that you could be burning twice as much, bikes just aren't geared at the same level walking or climbing stairs are, then I might give you closer to a 40% bonus to calorie counting.

Moral of the story, calorie counters must not be particularly accurate, take the numbers with a grain of salt. In fact given the vagaries of GPS antennas and battery saving measures of mobile devices, I wouldn't trust my distance or speed to be particularly accurate either.

bigbones73

Well, at 6'4" and 370 pounds perhaps riding half the distance that you did in less than half the time would yield a similar result?

I was just curious about this topic and there certainly appears to be a variety of opinions. I like Tractorlegs' take on this which is how I really feel. Other things about the biking are more rewarding than counting calories.

Mithrandir

It's slightly more complicated than that.

Let's compare you to someone exactly half your weight.

On a flat road you will use twice as much energy accelerating to 'cruising speed', but once you reach that speed your energy expenditures will be very similar to theirs, so long as you maintain a constant speed. At that point you are mostly fighting the wind. There's two factors there;

1) you have a momentum advantage. Air resistance affects momentum and will thus slow you down less than someone who weighs less than you. IE on a flat you will slow down slower.
2) You have a position/form disadvantage. A smaller person can more easily obtain a more aerodynamic position, which if done right can eliminate any momentum advantage you have.

On a hill you will use slightly less than twice the energy, depending on the grade. The higher the grade, the closer the number gets to 2.0x.

3%: 1.57x
5%: 1.76x
8%: 1.85x
10%: 1.87x
15%: 1.89x
20%: 1.9x


Now here's where it gets tricky. This is just plain raw energy. It doesn't factor in how well your body converts fat into raw energy. If you put out the same wattage as someone half your size it will take you roughly twice as long to reach to top of a hill. But if you go the same speed, you will need to double the wattage, meaning your heart rate will be higher and you could potentially be burning far more than just 2x as many calories. The trick of course is being able to put out 2x the wattage... not too likely.

Then of course what goes up must come down. Descending. Clydes have an enormous advantage descending, mainly due to the airspeed momentum benefit I mentioned earlier. The wind just won't stop us when we're going downhill. I've passed people half my weight pedaling furiously in the big ring, while I was just coasting in a tuck. And by passed I mean flew by them like they were standing still. Going downhill we definitely use less calories.

So there's the 'answer'. It's highly variable based on circumstance and weight. Climbing hills and then descending will burn a lot more calories though.

Mithrandir

Well I've got some bad news for you. There's no way you burned 800 calories in 8 miles.

For example, I biked 17 miles in an hour tonight, and I estimate I only burned 600-700 calories. In general, you're looking at about 500-800 calories per hour, and the 800 figure only applies if you're going really fast or climbing really steep hills.

TrojanHorse

Let's be honest, if you burned that many calories by riding 8 miles or just doing normal activities, you'd be thin as a rail.

Really take any calorie estimates with a HUGE chunk of salt. The other thing to consider is that not all 8 mile rides are equivalent. Your power output / speed will make a huge difference.

socalrider

You can calculate your calories burned using your heart rate vs hr max.. Lets just say an average workout will burn 8 calories a minute while an intense workout at 90% or higher of your hr max will burn 16 calories a minute..

If you rode at 15mph for your ride at the most you will burn 512 calories but your more in the 250-350 calorie range for a 32 min ride. You cannot burn more than 16 calories per minute. Most calorie calculators overstate by 20 to 40%.

sstorkel

I ride for an hour during lunch 3-4 days/week along a relatively flat course. My speed averages 15-17mph and my PowerTap power meter suggests that I burn 500-550 calories depending on wind and my average speed. That's right in line with with the 541 calories predicted by the Kreuzotter equations. If I weighed 500lbs and made the same trip, the equations predict I'd burn 896 calories.

Unfortunately, it seems unlikely that you burned 799 calories riding 8 miles... unless there was significant hill climbing involved.

Idak

Calories burned on flat ground is related to drag. Wind, rolling resistance... Drag goes up with surface area. Surface area goes up slower than weight. Since most of us are clydes because we are carrying dead weight (fat), the calories burned on the same ride, at the same speed, go up over a lighter rider. But it doesn't go up linearly with weight. For runners, at slower speed, most of the effort is moving your center of mass go up and down so, all other things being equal, calorie consumption is linear with weight.

At the high fitness level, power is almost linear with weight, this is why time trialers and track guys are heavier than the uber climbers. I will show my age. Miguel Inderain had more power per drag than Mario Cippolini. Even through Mario had a little more power per weight.

There is a clyde bonus. I would gladly not be entitled to it.

sstorkel

Not sure I believe these numbers...

The Kreuzotter equations predict that a 160lb rider on a 17lb bike riding a flat road @ 16mph for 8 miles burns 264 calories. Bump the grade to 3% and the burn is 602 calories (2.28X). At 20% the burn is 2476 calories (9.39X) at an average of 1267 watts.

Running the same numbers for a 500lb rider: a flat road is 459 calories, 3% grade is 1448 calories (3.15X) and the 20% grade is 6922 calories (15.08X) at an average of 3,542 watts!

I used 70 degrees Fahrenheit for the temperature, 67.7 inches for the rider's height, and assumed they would have their hands on the tops of the bars.

brianogilvie 

I think Mithrandir meant those numbers to indicate how much more energy a Clyde would expend climbing a hill than a rider half of his or her weight. They approach 2.0 (twice as much energy) as the hill becomes steeper and a greater proportion of the energy goes into overcoming gravity.

Mithrandir

Right. My numbers were the actual joules required to climb the hill. Attempting to calculate calories burned producing those joules gets much more difficult (since overall speed makes a huge difference), and thus I didn't even bother to try to state those numbers.

My intent was only to show that you will only obtain near twice as much energy output for twice the weight in an optimal condition such as a 20% grade. And that, ladies and gentlemen, is the first and last time you will ever hear anyone describe a 20% grade as an optimal condition.

sstorkel

To convert from kilojoules to kilocalories, you divide by 4.18. The body is only 20-25% efficient when cycling, so if your power estimate is for the bike rather than the human body you need to multiply by 4-5 to figure out how many calories were actually burned.

As a quick estimate, most people assume that kilojoules = calories.