My FTP is 340. So even on my easy rides around 68-70% I’m burning 800+ calories in an hour based off the kj. My easy runs are around 7:45-8 min pace so I’m probably only burning 750-800 calories in an hour. I was always told that running burns more calories than biking but I guess this isn’t true for me any more. Just another reason why the bike can be good if someone wants to lose weight. I guess you need to get your power up but still it’s decent calorie burning machine as it is to running.
You are a terrible runner compared to your bike ability so it’s does make sense that your easy rides burn more calories than your easy runs. I’d say get your run speed up and the do the comparison
You can also bike way more miles a week then you can run in a week.
I think maybe running (not walking) forces you to burn a decent amount of calories. Biking lets you sluff off on a ride and still be biking. For average out of shape person, running would burn more calories per hour. For an awesome triathlete or pro biker… maybe not 
Well, it also matters how much you weigh for running in terms of how many calories you are burning. If you are 250 pounds, you are going to burn more calories running 8min./miles compared to someone at 140 pounds running 8min./miles.
My FTP is 340. So even on my easy rides around 68-70% I’m burning 800+ calories in an hour based off the kj. My easy runs are around 7:45-8 min pace so I’m probably only burning 750-800 calories in an hour. I was always told that running burns more calories than biking but I guess this isn’t true for me any more. Just another reason why the bike can be good if someone wants to lose weight. I guess you need to get your power up but still it’s decent calorie burning machine as it is to running.
Alex,
How much do you weight? The old 100 Calories per mile estimator is good for a 150lber but low for heavier folks. Weight in pounds times .65 ought to give you a good value. If you only weigh 150lb you’re a absolute monster on the bike.
Hugh
I weigh 185
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Running has to be harder and burn more calories per hour than cycling.
Id check those figures.
I guess if you use the 0.67xweight in lbs for running it is by a little but I always went with 100cal per mile.
That’s an impressive FTP. You didn’t base that off of a Kickr workout did you?
That is inpressive, one day It’ll be mine along with that 4:45 IM split
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I weigh 185
I mistyped just a bit …it’s .65 X weight in pounds so that puts you at ~120 Calories per mile. One of those little 100 pounders is only burning ~65 Calories per mile. No wonder they’re always complaining they can’t eat much despite their mileage;)
Hugh
Running should burn slightly more kcal/hr than biking, but the advantage of biking is that you can log a LOT more hours. A three hour ride isn’t uncommon, a three hour run (outside of a race) is.
Also remember that riding outside means you are going to have times where power output is lower (ex. descending), so riding has built in “rests” that running (and indoor cycling) does not.
I have close to the same bike, run, and weight as you (slightly lower FTP, slightly faster easy run pace, slightly lighter) and I log my daily food intake so I have a pretty good idea of how many calories I can eat relative to the work done in each sport. From personal experience I definitely burn more calories running. My body weight fluctuates rapidly, and I will often see weight gain after bike days and weight loss after a similar effort running. It might just be that running shakes things loose, and the obligatory bathroom break after a run accounts for the difference, but this pattern has been very consistent.
I weigh 18584kg and you should be burning about 1 Cal/kg/km. 8:00/mi is 5:00/km or 12km/hr which is over 1000 Cals/hr or about the same as riding at 280W. Sounds comparable to me.
lots of stupid myths in this thread. If you got 3 hours to train, running will burn more calories hands down. If you say you are burning 800 cals in 1 hour on the bike, are you riding a fixie up a 25% grade hill? Most calorie counters over estimate burn rate on a bike.
cals burned per 1km running = your bodyweight in kg
cals burned per 1km on bike = take what is about multiply by 1/4
cals burned per 1km on swim = double the run burn.
Um…OK. You do realize that to burn 800 calories in an hour on the bike only requires approximately 222 watts average?
lots of stupid myths in this thread. If you got 3 hours to train, running will burn more calories hands down. If you say you are burning 800 cals in 1 hour on the bike, are you riding a fixie up a 25% grade hill?** Most calorie counters over estimate burn rate on a bike**.
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Including your thoughts on the possibility of the OP burning as many calories biking as he says 
340 X .7 = 238 watts = 857kj/hr =~857 Calories per hour at cruise power that he could sustain easily for an IM.
Calorie computers that base their estimate on measured power output are pretty darn accurate. I do agree that those that do not use power are often wildly optimistic.
Hugh
lots of stupid myths in this thread. If you got 3 hours to train, running will burn more calories hands down. If you say you are burning 800 cals in 1 hour on the bike, are you riding a fixie up a 25% grade hill? Most calorie counters over estimate burn rate on a bike.
cals burned per 1km running = your bodyweight in kg
cals burned per 1km on bike = take what is about multiply by 1/4
cals burned per 1km on swim = double the run burn.Not sure if you meant to respond to me but it seems you are mistaken on the amount of calories burned on the bike. I was over 900 Cals in a 1 hr commute home from work yesterday (in the rain) and my FTP is nowhere near the OPs.
While I agree that in general, running tends to burn more calories, there are enough exceptions that you definitely can’t blanket rule it.
For example, run 11min/mile at recovery pace, and see if you burn more calories than 1 hour all-out FTP test. Good luck saying that running burns more calories.
A pure cyclist who has no run background will almost certainly burn more calories on the bike than if you made them run.
800/hr on bike is only 222w for folks at 345w ftp, that can about be considered a recovery ride. not really, but really easy(at least indoors where there are no stops to factor in. it would only be 41 tss/hr
my indoor rides are a min of 900/hr on the bike on easy days and my ftp is not 345. most are closer to and over 1000/hr
edit: for instance, first hour tonight watching madness. I would have to run 10mi at the .65 number mentioned above. when I was running, that would last for about 2 miles and that was a long long time ago
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