Training & Nutrition - How many calories do I burn when I bike?

Hello everyone!

I have recently become a biker out of necessity, since a quad injury forced me to stop running for a time. Also, that same injury prompted some depression, which prompted some poor eating choices, which prompted the pounds to start piling. So, now that I've been biking regularly for a few weeks, I have some questions.

1. The weight has not been coming off like I had expected. I know that with running you can burn approximately 100 calories per mile, but what about biking? Right now, I'm averaging 125 miles per week on my bike, with a long ride on Saturdays between 35-45 miles long. I'm doing a little bit of "speed work" maybe once or twice a week, with easy rides in between where I don't pay any attention at all to my speed. I weight 135 lbs, and I need to lose between 10-15lbs. Diet-wise, I'm basically doing the South Beach Diet which doesn't seem to affect my biking one way or the other. Any suggestions here?

2. What is the comparative ratio between biking and running? If I bike 30 miles, what is that approximately in running miles? Or is it just the rate of exertion that I should be measuring? Primarily, my concern is how much running fitness can I expect to lose with the biking I'm doing now?

Thanks for your help, I really appreciate it!

btb

You burn about 500-600 calories per hour.


Check out the Health and Nutrition links on my webpage:
http://www.machka.net/links.htm

Doesn't biking calorie-expenditure relate to speed? I know that for running, calories is based upon distance regardless of speed, but biking has exponential increase in wind-drag right? So if you go twice as fast, you have to put out 8x the power?

Doesn't biking calorie-expenditure relate to speed? I know that for running, calories is based upon distance regardless of speed, but biking has exponential increase in wind-drag right? So if you go twice as fast, you have to put out 8x the power?

Yes, power output scales like the cube of speed, but 40 cal./mile for the typical sport class cyclist is probably a good estimate.

http://caloriesperhour.com

Everything you need to know about calories and burning them off. Later.

http://caloriesperhour.com

Everything you need to know about calories and burning them off. Later.


BAH! This calculator won't take my speed of 18.5 MPH for 100.9 miles!

BAH! This calculator won't take my speed of 18.5 MPH for 100.9 miles!Interesting to see that I burn off close to 1000 calories more by riding the century at 17.5mph vs. 12mph. Too bad it doesn't go high enough to figure out my real century speeds... :(

Try this:
http://www.kreuzotter.de/english/espeed.htm

Hello everyone!

Thanks for the input, I appreciate it!

500-600 calories per hour? Wow. I had been figuring on about 30 cals per mile.

btb

That kreuzotter calculator seems a little low to me. No way I burn just 2700 calories doing a century @ 20mph. Here's another one from Bicycle Ride Calorie Calculator v1.01 (http://www.geocities.com/SiliconValley/Vista/6434/CalCalcApplet.html) that seems to match the caloriesperhour.com one, but allows speeds higher than 17.5mph...

Try this:
http://www.kreuzotter.de/english/espeed.htm


was going to offer same link.

I use a modified south beach. South beach is pretty good for the days on which you don't exercise, but it's not good for days in which you exercise. Make sure you get some quality carbohydrates before a long ride (clif bar and accelerade for me), and carbs during and after. Aim for something like 250-350 cal/hour - you want to take in enough carbs to offset the carbs that you are burning, but not to offset the fat that you are burning. If you do that, you should have a big appetite at the end of your rides.

If you don't fuel with carbs, you'll compromise the benefits of the ride (both for aerobic development and for weight loss).

You should be able to maintain most if not all of your aerobic capacity through cycling. You may lose some of your running muscles, however.

It's hard to lose weight and gain performance at the same time. If you're working hard, you don't want to be loosing weight very quickly.

I use ~20 kcal/km (~30 kcal/mile) for myself. It's in the ballpark, and that's the important bit.

Hey Eric,

Would you consider yourself in phase 3 of SB? I think that's mostly what I did when I was running a lot of miles.

The funny thing about cycling is that I don't seem to bonk...at all...during my long rides, even being on the SB phase 1! And I do ride long...usually around 30 per day, not real fast (maybe 12-13mph) but still pedaling constantly. I never could have run very far on phase 1.

You're right about losing my "running muscles". I have been running little bits here and there, (a total of 24 minutes this week...:D) and I feel like my legs are just learning how to run again! My IT band is starting to bother me, which wasn't the injury that stopped me from running before. I know I'm derailing my own post here (is that allowed?;) but I'm wondering if I'm doing something style-wise to aggravate my IT band. Could my bike also need adjustment? The pain is mostly in my hip, not so much my knee. And, my hip only bothers me when I'm trying to run a bit, not while I'm biking.

Thanks again!

btb

Hey Eric,

Would you consider yourself in phase 3 of SB? I think that's mostly what I did when I was running a lot of miles.

The funny thing about cycling is that I don't seem to bonk...at all...during my long rides, even being on the SB phase 1! And I do ride long...usually around 30 per day, not real fast (maybe 12-13mph) but still pedaling constantly. I never could have run very far on phase 1.

You're right about losing my "running muscles". I have been running little bits here and there, (a total of 24 minutes this week...:D) and I feel like my legs are just learning how to run again! My IT band is starting to bother me, which wasn't the injury that stopped me from running before. I know I'm derailing my own post here (is that allowed?;) but I'm wondering if I'm doing something style-wise to aggravate my IT band. Could my bike also need adjustment? The pain is mostly in my hip, not so much my knee. And, my hip only bothers me when I'm trying to run a bit, not while I'm biking.

Thanks again!

btb

I never did phase 1 and 2, because I didn't really have much weight to lose - I just wanted to be healthier. I am essentially on phase 3.

Bike position can certainly cause IT band problems - seat too low is one possibility.

I could probably ride a long long time at 12-13 MPH without extra nutrition. Riding at 18-20, I use a hydration drink the whole time - there's nothing worse than bonking in the middle of nowhere with no stores around.

Try this:
http://www.kreuzotter.de/english/espeed.htm

Kewl! According to this, I'm at the starvation threshold. :)

On the other extreme, we have this site which over-estimates by 200-300%: http://www.gmap-pedometer.com

On the other extreme, we have this site which over-estimates by 200-300%:

Note the name of the website. "pedometer" as in walking.....

Note the name of the website. "pedometer" as in walking.....yeah, that's really odd, because walking a certain distance will certainly burn off fewer calories than riding that distance at 20mph. For a 60-mile ride I did last weekend, it calculated 8800 calories :eek: !!! I would think that walking that distance would've only burned off 2000-2500 calories max. Riding it at 20mph would probably burn off 3000. I'd like to see the mathematical models these calculators use to compute their calorie totals.

man... it's nearly a 1000 calories just for one work day...:eek:

yeah, that's really odd, because walking a certain distance will certainly burn off fewer calories than riding that distance at 20mph. For a 60-mile ride I did last weekend, it calculated 8800 calories :eek: !!! I would think that walking that distance would've only burned off 2000-2500 calories max. Riding it at 20mph would probably burn off 3000. I'd like to see the mathematical models these calculators use to compute their calorie totals.

Riding is far more efficient than walking or running, so energy spent walking a specific distance should be much higher. 8800 for 100 km sounds too high, but riding a bicycle is at least twice as efficient, so if you spent 3000 kcal riding, you'd be looking at maybe 6000 walking.

I can't put much faith in those calculators. When trying to gain weight 3-4 years ago I was eating 6000 calories a day and barely gaining. Everybody's metabolism is different, the numbers those spit out are guesstimates, you can however get your BMR checked to get some kind of baseline number of what you burn in a day.

Fitday is pretty good at spitting out calories burnt that are simillar to my Polar HR monitor for the given activity. Arent they all just estimates anyway. Later.

yeah, that's really odd, because walking a certain distance will certainly burn off fewer calories than riding that distance at 20mph. For a 60-mile ride I did last weekend, it calculated 8800 calories !!! I would think that walking that distance would've only burned off 2000-2500 calories max. Riding it at 20mph would probably burn off 3000. I'd like to see the mathematical models these calculators use to compute their calorie totals.

Did it ever occur to you how long it would take to walk 60 miles.... At 4 mph, a brisk walk, it would take you 15 hours. You could jog it, but it would be like running 2.3 marathons. It is certainly more work to cover that distance on foot than on a highly efficient bike.

I'll tell you that from my experience, I only lose weight when I eat like a mofo! When I don't eat a lot (of the right foods) when I cycle, I don't lose weight, but rather my body turns what little I do eat into fat because it thinks it's starving and that it needs to store fat instead. I bike around 150 miles a week and found that if I eat a TON of food, I lose weight easy. I also weight train a couple times a week to maintain upper body strength. If I don't eat, I bonk instantly and it takes days to recover.

For instance, I rode 55 miles today in 3hrs... went through tons of water and about 5 gel packs... got home, ate an apple.. hour later I ate 2 full heads of brocolli, 4 chicken legs, and about 1/4 lb of sphaghetti... I'm about to explode, but it's that 4hr window you have after exercising to get in 3g of carbs per kg of body weight to maximize carb absorbtion... for me, at 90kg it works out to about 270g of carbs within that 4hr window... I bonked bad on wed after only 15 miles (like almost collapsed 'cause I didn't eat much for the 2 days prior to that and had to leave work kinda bonk), ate crazy amounts of food for 2 days, then did 55miles today no problem.

I got a lot of good info from this website and it's helped improve my cycling tremendously. Nutrition is 2nd only to getting on that bike and riding!

http://www.cptips.com/nutrtn.htm