Chaco

I've seen a lot of calorie measurements in the forums that are really ridiculous, all the way from 800 calories per hour (possible, but not likely) to 1,600 calories per hour.

Looking at Juan Antonio Flecha's power meter statistics helps put things in perspective.

Flecha's Functional Threshold Power (FTP, or the average power a rider can produce for 1 hour without fatiguing) is a massive 420 watts. The average young male novice cyclist in reasonably good condition has an FTP of 200 to 230 watts.

With this in mind, look at Flecha's calorie consumption in the TDF in the first 9 stages: 34,569 calories in 39 hours and 2 minutes, for an average of 886 calories per hour. That means if you are a young novice male in reasonably good shape, your calorie consumption per hour is likely to be around half of Flecha's, or 443 calories per hour.

The calorie consumption per mile is even more sobering: 989 miles in 9 stages, which equals 35 calories per mile. So, if you can produce the power output of a Flecha, then you can reasonably claim you burned 350 calories in your 10 mile ride. But if you're a clydesdale like me, 20 to 25 calories per mile is about the best you'll do, and even that's only if you're pushing it pretty hard.

freighttraininguphill

...and this is one reason why I love climbing so much. It burns more calories, and I don't have to force myself to ride hard. The hill takes care of that part for me.

dsprehe89

I don't have any science to back my believe up, buy I have to disagree completely with you one that. First off, every persons body works differently and burns calories at different rates, and on top of that, from what I have always know, heavier people burn more calories than lighter people because they have to do more work to move their body compared to the lighter person. With knowing that, I would think that a clyde would burn more calories in 1 mile that a light 130lb person.

Teon

I would imagine that a lot of it also has to do with the type of bike you ride, the weight of the bike, what sort of terrain you ride, what sort of elevation changes exist on your ride, if you have a tailwind or headwind, etc., etc., etc......

Studies like this are good, but usually they seem to be only useful in estimating a range, i.e., depending on all the variables, you'll most likely burn anywhere between 200-500 or so calories per hour of bicycling. And even with that wide a range, I would imagine that one would still encounter a very broad YMMV.

It's a good thing that I enjoy bicycling so much, as the sheer joy of riding keeps my mind from thinking about these kinds of things.

youcoming

There are a lot more factors involved here. One is effecincy. I will never be able to produce the watts of a pro as my body is not as effecient. They can maintain those level through training and that training enables the body to produce said watts with less calories burned. And as stated everyone burns them differently, I have no idea how many calories I burn by riding but I'm sure it's all relative to a degree.

Drew Eckhardt 

Only if you're racing 2000 miles in 24 days (only 2 off the bike) with centuries on 15/21 riding days and up to seven in a row.

Looking at a representative hard week totaling 3616 kilojoules I average 593 kilojoules/hour (560 - 700 Calories with cycling metabolic efficiency varying from 20-25%) over 6:06 time on the bike 4/7 days. One 42 minute hard effort (5 at zero power, drops the average) totals 508 kilojoules or 725 kj/hour (690 - 860 Calores an hour).

I have weak spindly legs good for a 235W critical power with 3616kj averaging out to a pleasant 165W endurance pace (stopping for traffic lights, phone calls from my wife, etc. included).

3616 kilojoules over 95.4 miles is 38 per or 36-45 Calories per mile and 360-450 Calories/10 miles or 508 kj / 11.8 miles is 43 kj per mile or 41-51 Calories/mile.

There's a difference between sustainable power an hour at a shot, a hundred miles at a time, on a 418 mile week long supported tour with 30,000 feet of climbing, or (I'm guessing on this one) racing 987 miles in 9 days.

Bike racing isn't about average power.

40 Calories/mile is a pleasant couple hours in the hills. A few thousand quality miles in your legs with some structure help to get there.

CraigB

I was told there wouldn't be any math.

mkadam68

A couple thoughts:

• Ratio of FTP doesn't have anything to do with ratio of kcals when comparing two individuals.
• If speed is the same, moving a larger mass requires more energy production than a smaller mass, therefore more kcals expended.
• The more efficient an engine is (human body), the less energy is required for the same power output, i.e.: fewer kcals for the same wattage.

bautieri

I've been saying 30 calories a mile now for some time providing you are riding flat terrain and not coasting downhill. Hills, figure more but what goes up also goes down so maybe they average out. There are too many variables to peg a solid number, but I wholeheartedly agree that the calories burned estimate by calorie tracking devices are wildly optimistic. Often laughably so.

RandoneeRider

We might add that the human body is the single most efficient collection of parts-is-parts capable of adaptating to the environment and what fuels it. Repeat any given task over and over again, the body will learn (in short order) how to use the least amount of energy to complete said task.

All that I'm suggesting is (and I'm no dietician or expert in the field),
regardless of whether you're 'fat' or a fine tuned athlete, what used to require a given amount of calories to accomplish something.... may require less effort (calories too?) as the task is repeated and becomes less of a challenge (to the body).

That may be why I've run into people who insist that they rode a bicycle to lose weight, only eventually to become dissapointed that they could no longer lose the weight they did when first starting out. Even after only a couple months, I've noticed that it no longer takes the effort nor the energy to complete ten miles (on the bike) than I remember when first starting out. I've had to mix it up by finding different courses, either with hills, or flat and little wind where I can increase my average speed, or short bursts of having to stop & start again. Lately, I've thrown a curve at the body by walking three miles first thing in the morning...... and these leg muscles are REALLY hurt'n (and a bit confused) the last couple weeks!

sstorkel

The question is: will the Clyde toodling around the neighborhood burn more or less calories in one mile than a world-class bicycle racer who is pedaling along at 25mph? Aerodynamic drag being with it is, I suspect the fast guy burns more calories...

Drew Eckhardt 

Who are riding in the same group and taking the same length pulls.

Riding solo it's the most significant thing because the intensity you pick is some fraction of FTP - maybe 105% for hard 10 minute intervals, 85-95% for an hour sweet spot ride, 60% for a century.

At the same perceived intensity a big fit guy with a 300W FTP can do 100% better than some one out of shape at 150W.

Disregarding the solo ride scenario where speed can be whatever it needs to be -

That's only appreciable at low speeds (where rolling resistance dominates power demands) and on hills (where most of your power is going into hauling your carcass to the top).

On dead flat ground a 145 pound climber might take 158W to cruise at 20 MPH and 174W after he grows to 250 pounds in middle age. That's 10%.

OTOH a 2 MPH speed increase may demand 204W from the lighter rider burning 30% more calories over the same time or 20% more over the same distance.

Cycling metabolic efficiency varies from about 20-25% or .95 - 1.19 C / kilojoule. The 25% variation from efficiency pales compared to the 100%+ variation in FTP or the same fraction of it.

gyozadude

A number of states produce calorie-charts for work/exercise done. And Wisconsin produces some data and it matches what Physics would tell us. Cycling one mile and the energy consumed doing it is basically a function of linear work (i.e. - here comes the Math: Force x Distance). Force is equal to mass x acceleration where mass is the mass of the bike and rider and gear, and acceleration is what is necessary to overcome the sum of wind and rolling resistance and other forms of dissipative friction.

What this tells you is that for distance being the same (1mile), and rolling/wind resistance just a slightly higher number for bigger riders on less race-oriented bikes, the major factor in how many calories get burned per mile is mostly body mass and maybe a little due to frontal area and higher rolling resistance. Bigger person, more calories spent per mile. So for someone 130lbs on a 20lb bike, it's around 35 calories/mile (or 20 kcal/km for those not in the US). For someone 155 lbs plus 20+ lb bike, it's 45 cals/mile, and someone 190 lbs, it's a bit over 55 cals/mile - according to Wisconsin. See https://www.livestrong.com/article/13...king-one-mile/. And the variance is relatively small because Work has no time-component in it's factor. You could ride slow or fast. At higher speeds, you work for shorter time. Work may increase slightly at higher speeds because wind resistance increases as the cube of relative windspeed. But for bigger riders, the frontal surface area to mass ratio increases more slowly, to counter-act that cube-power increase.

So someone who's like 300lbs on a bomb-proof tank bike, may expect to burn 80 calories/mile. So if someone rode 20 miles in 1hr 20 min. Then 80cals/mile x 20 miles = 1600 cals. Yes. I used to ride 20 miles a day in college. I ate 6000 calories a day. I was 255lbs and built like a linebacker with just 7% body fat. It takes a body mostly muscle about 35 cals/kg of wt. to just survive and maintain weight. That means, if you weight 116 kg, just to support that weight, you must eat 116kg x 35 cals/kg = 4000+ cals per day! Yes! You can eat two slices of Costco pizza AND a chicken bake and not gain weight if you are mostly muscle and big. Then add the fact that you ride 20 miles per day, with 3000+ ft of elevation gain. That adds another roughly 85 cals/mile x 20 miles = 1700 cals. And we getting close to needing to eat around 6000 calories per day just to maintain weight.

However, here's the problem - if you get sedentary and put on fat, the body shifts and now you only burn 30 cals/kg of body weight. That's a 14% drop in calories needed. So if you stop riding, get fat, then you must cut 14% off the 4000kg maintainance, plus you aren't burning 2000 calories a day in hill work on the bike. So you gotta cut something like 2500 calories per day out of the diet. That's brutal for folks who love to eat. If you don't - then it's easy to put on even more fat, over load the liver, over load pancreas, increase chances for diabetes, etc.

BigUgly

The other day while going down a steep descent I was trying to produce 1.21 gigawatts so that I could get up to 88 mph. Unfortunately there weren't any thunderstorms in the area where I could poach a lightning strike or two. Needless to say instead of getting back to 1982 when I was skinny, I am still stuck here in fat 2011! (although not as fat as 2010).

All this math is making my brain hurt. Don't stuff yourself, stay away from soda and processed foods, and be active. Ride, Run, Walk, hike, row a boat, swim, take the stairs, go to the 'Enchantment under the Sea' dance, etc.

Dislclaimer: "No work was done while creating this message" - sorry I am bored, don't feel like working anymore and just passing time until the whistle blows

Teon

Crazydad

When did having a degree in data analysis become a prerequisite for losing weight on bike? How about we quit worrying about cal/hr, watts, etc. and just go ride?

jethro56 

Last summer when I first got my Garmin FR60 HR working to read Calories with the foot pod. I went on a long walk (7.2 miles) If I remember correctly it said I "burned" 1100 Calories. I went on long walks every day for 2 weeks. I then repeated my 7.2 mile walk... 600 Calories. Did I get in that much better shape? I think not. I probably got more efficent walking and my HR dropped nearer some baseline number that the equation used as a "no effort" level.

Chaco

Now my head's hurting too! I'm almost sorry I brought this up!

Granted, heavier people use more calories when they move. But in general, they're also less capable of sustaining high energy output, or even getting there in the first place.

In other words, I think using an average of 20 or 25 calories per mile for a Clyde is just about right. Much above that, and it's more like a rationalization to eat stuff you shouldn't.

goldfinch

Heavier people simply burn more calories to exist. My resting metabolic rate at 126 pounds is much, much lower than someone's metabolic rate at 250 pounds. And giving equivalent effort in exercise the heavier person is going to burn more calories.

dahut

Which explains why my arse remains the size of a couch cushion.

Crazydad

I agree that calorie counters are way optimistic. But comparing anyone to a pro level cyclist is a waste. Not to take this thread down a rat hole, but pro level athletes also have genetics on their side. Endurance athletes like cyclist have a more efficient metabolism than the general population, otherwise we all could be TDF riders with enough training. Pro athletes have a genetic advantage that allows them to be stronger, faster, more efficient than than normal. Even if I started training as a kid, I would never have approached the level of a TDF rider because it is not in my genes. So to use Flecha or any other pro athlete as a baseline for average people is unrealistic.

gyozadude

You don't have a flux capacitor on your bike? :-) And what's with the aversion to arithmetic? My job used to be coding the most efficient computational Physics algorithms and optimizing compilers for supercomputers. Talk about Math and dealing with artificial viscosity for some of these problems. Rewriting the Berkeley Lab gene sequence search algorithm in base 4 math was far easier than some of the Navier-Stokes simulations for Thermo-Nuke detonations. But heck, it pays the bills and they serve free Mtn. Dew and Diet Cokes in the frige at work.

dahut

I'd agree in the main. Comparing yourself to Flecha is bound to deliver nothing but a body blow to your esteem.
Let me make a suggestion.

GO ride tomorrow.

If you are huffing and puffing and your abdomen hurts from the exertion (not to mention your legs), then you are in the zone.
If you can keep that up for an hour, regardless of the terrain, then you have surpassed the vast majority of your fellow 50 years olds.

Have a beer in celebration of your accomplishments and put away the calculator. You sir, have done something special. Hoorah!

Crazydad

Amen! Just ride!

jethro56 

I remember when they added ones to computer programming. Writing code in all zero's was tedious. Of course then we had to make sure that none of our wires were kinked.Zero's would be able to flow thru kinks, but ones tended to get tangled up and cause blockage.