A runner friend of mine told me that you can calculate (very roughly) the calories burned during a run by multiplying one’s weight in Kilograms by the distance in Kilometers.

Does anyone know of a similar formula for bike riding? I realize that speed plays a role in both sports, but we’re talking good hardy training (bike average speed of 26 km/h (15.6 mph).

On a similar note, I saw once a bike/running comparison which said that a distance ratio of 5 to 1 would result in about the same work-out. Since the Tour de France riders regularly do 200km, by this calculation they are effectively doing the effort of a marathon (42km) twenty days in a row! We all know that the TdF is the height of endurance sports, but this ratio seems way off to me. My friend and I thought 8 to 1 sounded much better. Any opinions?

My magic ratio is 7:1. A 20 mile (32.2km) bike ride is roughly equivalent to hoofing it 3 miles (4.8km).

One more thing.

If you want to burn more calories, crank it up, or head into the wind. Your calories/mile increase as your average speed increases due to increased wind resistance.

It is about 4 or 5 to 1 if you do it right. Try riding faster you will see. That 4 this is correct. You can't really consider a 20 mile ride at 15mph a hardy training ride. The guys in the tour average this up mountains.

I don't think there's any sure fire calculation to this.

A few weeks ago, I went to a performance laboratory where they had me put on a mask that covered my nose and mouth. They attached a heart rate moniter to me and had me ride a bike. By measuring my oxygen intake and monitering my heart rate, they were able to tell me exactly how many calories I was burning at a specific heart rate. The readout they gave me came from the computer that was connected to my mouth that measured the maximum amount of oxygen I was intaking while riding.

You can also do this test while running.

As far as I know, these types of tests are the ONLY way to measure the amount of calories that one expends while exercising. The usual calculations and myths out there that people typically use to try and estimate their caloric output are flawed- no one person's body type is similiar to another person's. There are a lot of factors that will influence the amount of calories you burn while exercising- from how fast or slow you ride, to how high your VO2 max is, to how much testosterone a person has, to what percent heart rate you exercise at, to how much lean body tissue (muscle) a person has.... all these things need to be taken into account, plus a lot of other factors.

I know there are some great places out there in Germany you can go to get tested. My suggestion- if you're truly interested and serious about knowing about caloric intake, find a high peformance facility where you can get tested. The best ones are the ones that will check lactic acid levels and have you wear the mask that measures your oxygen intake and records the measurements on the computer. Otherwise, all those methods everyone discussed is no more accurate than taking some numbers and putting them on a dart board and throwing a dart at the numbers to determine your caloric expenditure.

Good luck, and start looking for a facility to get those answers! Then get a heart rate moniter and start measuring your performance for real!


Koffee Brown

Thanks for the info on getting tested. I think we were having more of a coffee table discussion about it, rather than wanting all the science of getting tested--although you're certainly right about the value of being scientific about it, and about the heartrate monitors (where the differences between running and cycling are rather interesting).

With respect to the ratio question, I still think that 4 or 5 to 1 is too high. This ratio is speed independent. Just as there are the pros in the Tour and there are many serious cycles who don't quite meet those speeds, there are elite runners who pack a 2:10 marathon and there are very respectably fit athletes who need 3+ hours. I don't see anyone organizing events of 20 day, 20 marathons one after another. Sure there are 3-day marathon events and 12-hour runs and so forth. But, someone who holds that 4 or 5 to 1 is correct needs to come up with an argument and evidence to convince me. (And, by the way, 15-16 mph, is a "beginning of the season average" and I was talking 40 to 80 mile rides, not 20.)

Cheers,
Jamie

Why the guys on the tour can do this is because cycling does not beat your body up like running does. Your knees, feet and back could not take the pounding of running those distances day after day. But people do do 100 + mile long running races.

SRM cranks have a force measuring device, so they can calculate the amount of power the cyclist is applying. Compined with a cadence facility and a heartrate moinitor, you can do some pretty good analysis of power output and efficiency.

i think the reason it's hard to have a ratio here between running and cycling is that running is comparitively simple - raise foot and move body forward and wind resistance is less of a factor at running speeds - cycling has the drivetrain and gears and wind resistance and tire pressure, etc. that determine how many calories are needed for a given distance and so many are rider-dependent...

as far as tour de france - i agreee with the post that it has to do with running's high impact nature on knees and back - there are guys that do a marathon every weekend (some 70 year old guy has done like 40 a year for 12 years or something) - but most people like me who had knee problems just TRAINING for a marathon... cycling is so much easier on the body, so if you can generate the power and fuel your body for the endurance than tdf is possible, but if there were a 20-day marathan-per-day i think most of the field would drop out before the finish which is not the case in tdf...

as a general rule, i would think at low speed 'recreational' riding something like 7:1 might be correct but at high speed i think the 4 or 5:1 does sound more correct due to air resistance which increases much more than linearly as speed increases... from 30-40mph most of the difference in energy is not basic power (force x distance) but because of wind drag.

I bike and run regularly. When I run, I cover a 5 mile course at 8 min miles. When I bike, I cover a 20 mile course at 17+ mph. At the end of a run, I'm pretty tired; but at the end of a ride, I'm wiped out. My legs are like rubber bands.

I like the 5:1 ratio.

For me it is exactly the opposite. I can ride all day at 17 mph. But, I have my doubts whether I would even survive a 5 mile run. Okay, I am not a runner. Perhaps natural preferences and differences in physiology play too much of a role for any ratio to make sense for a broad group of folks.

I've read everyone's points on wear and tear on the joints, mechanical advantages on the bike, wind resistance and all. But, I still want to know how the TdF riders can possibly be doing the equivalent of a marathon-a-day 20 days in a row. Perhaps elite marathoners could do this if their knees would hold out.

Cheers,
Jamie

Cribbed from:

https://www.discoverfitness.com/MET_value_table_.html

"To determine how many calories you are burning from a given physical activity, you need to know three things: (1)your body weight in kilograms, (2)the amount of time you performed the physical activity for and (3)the rate of energy expenditure (expressed as METS), which you will determine from the table below.

...
Bicycling: 12-13.9 mph, 8
Bicycling: 14-15.9 mph, 10
Bicycling: 16-19 mph, 12
Bicycling: > 20 mph, 16
Walking: 4.0 mph 4
Running: 6 mph (10 min. mile) 10
Running: 6.7 mph (9 min. mile) 11
Running: 7.5 mph (8 min. mile) 12.5
Running: 8.6 mph (7 min. mile) 14
Running: 10 mph (6 min. mile) 16 ... "

According to this table, running at 6mph and bicycling at 15mph require comparable caloric expenditure PER UNIT TIME, implying a calorie/distance ratio of 2.5:1.

They dont. The drop out rate is about the highest for any professional sporting event. Everyday there is a cut-off time and riders who are late are out of the game.

The leaders are helped by their team mates, who shield them from the wind, and generally put them into a race-winning position. These domestiques would be expected to ride themselves out of the race if neccessary.

Not everyday is an all-out race. The leaders establish their lead in the time trials, and maintain it in the mountains, but on many sections, they do just enough to stay in the lead, and no more. On these days, lesser riders and specialists make a bid for the winning line. A stage win can mean big earnings, so riders may blow their chance of finishing for a stage. This is part of the tactical side of pro racing.

There are rest days, the riding is not 20 consecutive days, and some of the stages are shorter than others.

For many, just finishing the TdF is the highlight of their career, and there is a special prize (The Red Lantern) for the rider who finshes last.

I see the chart.

Does the weight take into account lean body mass vs. being a doughboy?

Does the chart account for male vs. female?

Does the chart account for people who are better at running than cycling?

The most important question- does size really matter?

Question, questions, questions.....


Koffee Brown

Ok, I have a question for you, now, my friend.

Why do you want to know the answer to this difficult question, one which has so many variables, such as body weight, wind resistance, etc.?

My friend's and my reason for wanting to know this came from idle chit-chat about our sports. In fact, neither of us is particularly calorie conscious. Somehow, I think we had the idea that calories burned would be *a* way to compare the two sports. But, in reading these posts and in thinking about it, I have certainly come to the conclusion that such a comparison is really hard to make in any meaningful way.

Cheers,
Jamie

First, let me apologize for resurrecting this old thread.

I am not concerned about calories, in general, with respect to my cycling. However, my Polar M52 HRM changed my life by showing me how few calories I burned during strenous workouts. BTW, I don't work for Polar.

The M52 allows you to input your age, gender, weight, height and activity level (high, med, low). Then using this information and the heart rate data from your workout it will give you calories burned - during the workout and at the end.

I believe it to be fairly accurate. . . or at least, accurate enough if you care about calories. My observations, based on 2 years with this HRM:

1) Calories consumed is totally dependent on the intensity of the workout. In my case, while on my wind trainer with no interruptions, 500 calories per hour is a pretty good zone 2-3 workout, 700 - 800 calories/hr is a hard zone 4 workout, but in an XC race last September I burned 1,000 calories in one hour. Yes, I was trashed for two days. I'm confident that were I running for an hour in the same HR zones, I would have burned the same calories.

2) After observing how hard it is to burn 500 to 1,000 calories in a workout, I changed my eating habits and dropped 30 lbs. I had always thought I was burning a lot more calories. Basically, I had to kill myself for an hour to burn off a Big Mac, fries and a Coke.

3) Now the calorie counter feature of the HRM is not of much use to me, I'm ready to move on to a new HRM.

4) As my fitness improved and I lost weight my calorie burn stayed fairly constant, but I went a lot faster.

5) Don't compare sports, compare intensities.

I read that Lance's average HR for a flat stage in the TdF is 128bpm. Keep in mind that he's in the draft, but 128 is in my recovery zone and I'm 42 yrs. old. I'd bet he's not burning 400/hr at that level of intensity.

A friend of mine who was into sports physiology and crap like that used to tell me there are 3500 calories in a pound of fat; during exercise, of moderate to intense effort, the body will burn approximately 500 calories per hour. He used to claim that a person who walks vigorously will burn just as many calories as the guy on a bike or a runner if they each do it for the same length of time. The biggest fluctuation in body weight is caused by the loss or retention of water.

well, a marathon for a runner is 26.2 miles. for the biker it is a century at 100 miles.
Where did those numbers come from (well other than greek times) ... don't they equate the the sort of ultimate in distance each in their own respect? (not talking about ultra marathons now)

I believe this to be true. To put it onto perspective: To lose 2 lbs of fat per week you must strip 7000 calories from your person. That might mean, on average, eating 500 calories less than you usually do each day, and excercizing to burn 500 calories each day for 7 days. This is why it's hard to lose much more than 2 lbs per week and keep it off!!

Dax

There are a lot of variables in this.

Are we talking about burning calories or losing fat?

As for burning calories, you should be able to estimate it from speed and weight of rider. But the best way would be to measure the CO2 expelled by the rider during the ride. But I rather doubt that anyone has done that one.

A lb of fat has 3500 calories. But to lose a lb, you might not lose a lb of fat - you probably lose a little bit of water and tissue associated with the fat and again, I don't think that is really a known thing.

For me, a good finagle facter for calories burned is 30-50 calories per mile. On long tours with big miles and climbing, I can eat a bunch of food (as long as I avoid calorie packed fats) and lose 1 lb per day. So I am consuming something like 2500 calories and still running a 3500 calorie deficit. That suggests, for me, that the 50 calorie per mile is probably closer to actual. Of course, people on the same tour GAINED weight but they did not pass up an opportunity to eat all the fattening food they could gobble up (and they probably sagged a few times too).

I think it is 5:2 because my heart rate is around 75%-90% when biking and I only travel 9 miles in 35 minutes. I travel 5 miles when running but I think I burn more when running because more muscles are being stressed.