Calories: treadmill v pavement

my guess is that fewer calories are needed to run at the "same speed" on a dreadmill, because the ground is effectively moving beneath you, you're not having to propel your body forwards in the same way. it's difficulty to get a 100% accurate measure of calories used during activity, but a decent rule of thumb is that you'll burn about 100 calories per mile running outside. Perhaps a little more. it shouldn't make a significant different what pace you're running at. Calories are a measure of energy, and the force required to move an object of mass X over a distance Y should be the same regardless of the speed, so the energy required to generate that force should be pretty much the same regardless of speed.

Cue a lengthy and heated discussion of armchair physics and biology, in which someone will no doubt compare someone else to Hitler.

AgentGinger wrote (see)

my guess is that fewer calories are needed to run at the "same speed" on a dreadmill, because the ground is effectively moving beneath you, you're not having to propel your body forwards in the same way.

That's pretty much what happens when you run outside though.  When you start running you gain forward momentum, so the relative motion is (broadly) the same.  If you didn't "propel your body forwards" on the treadmill, you'd fly off the back!  The biggest difference is that running outdoors you also need to overcome the force of air resistance, and this is the main reason that treadmill running is relatively more easy.  (Another variable that may partly even this out is the lack of cooling effect when running on a treadmill, unless you've got a fan blaring away.)

So I reckon I'd also think calorie expenditure is more - for a given speed - outdoors, but even if that's right I bet it's negligible.  Perceived effort can work either way; some people perceive treadmill running to be harder, either because of boredom thresholds or just the concentration of staying on the thing; other people might move from treadmill to outdoors and find that harder either because of the new requirement for working out your own pace, or because of the impact of running on a different surface.

I always think of bisuits as being half-a-mile each.  (50 calories).

From my armchair () I'd say that outdoor running is slightly more calorific too.  I'm not sure you can say that speed has no influence on calories burned though.  If I drive my car for 10 miles at 40mph, it burns far less petrol than if I drive the same distance at 80mph.  I think it's the same with the body...  if you get above the aerobic threshold, then you burn your fuel more inefficiently (as your muscles desperately seek rapid access to energy), so you use more calories for a given distance.

There's the complication that slower running burns body fat rather than stored glycogen... so altough slower running might burn fewer calories, I think that it is probably more effective for PRACTICAL weight loss.

I hope that some other physiologist well give me a critique from their armchair.

Why an enquiry about calories?

There's a synopsis of the whole debate here:

http://www.weightlossresources.co.uk/exercise/running/road-versus-treadmill.htm

I always feel like the treadmill is harder work.  I think its because, even if I've set it at a comfortable speed, I'm running RIGHT at the front of the thing because I'm so scared of flying off the back.  Apparently, the gradient is a big deciding factor.  I put it at 2% - my knees do not react well to landing on a flat treadmill - and apparently that helps.

I found the treadmill good prep for running outside, but also found different muscles working/hurting/needing stretching once I started making it out of doors. 

Good luck with those pavements - I'd pick them over a gym every time now!

I don't think there will be a significant difference between the two in the number of calories burned.  If you run for longer you will burn more calories - so have a go at running outside, if you enjoy it more you are more likely to run for a longer amount of time and therefore burn more calories.

Outside in the cold, if not dressed up too much you'll burn 1000 kcal/hour running or walking.

The only problem is resisting the urge to attack a cream doughnut on return.

Damn! I'm thinking about cream doughnuts now.

Mmmm doughnuts 

i can testify for this as i built up my running career on the dreadmill.

its alot harder outside so more calories burnt there, plus like RicF said take the chill factor (or excessive sun) and youve got extra calrofic running 

stutyr wrote (see)

I don't think there will be a significant difference between the two in the number of calories burned.  If you run for longer you will burn more calories - so have a go at running outside, if you enjoy it more you are more likely to run for a longer amount of time and therefore burn more calories.

Unless we start taking calorifiers (is that right?) out on our runs, I don't think we'll really know what the difference is, so in the mean time I agree with stutyr that, in practical terms, what will be most significant is whichever form of running gets you out there for the most amount of exercise.  I just wouldn't burn as many calories if I only had the treadmill to run.  Would send me round the bend.

Calorie counting (consumption vs. expenditure) is fraught with error on both sides, so even if you knew the answer I don't think it would be of much practical use.  Eat more healthily and do more exercise, and the balance will shift in the right direction.

I only bought a dready a few months ago and still getting used to it. Just bought it for an occasional alternative... However I am really slow on it. I can run far quicker outside in the wind with hills. 

So for me my effort is a lot more so I imagine I would burn more calories on it.

Sounds great Debs! I started running on a treadmill and would regularly run on the thing for 1.5-2hours ut for me it was to do with pacing - I just couldn't seem to get the hang of it when running by myself outside and would just knacker myself much too early. Eventually though I started to go outside and now I would never swap back - something about being in the open air has just so many psychological benefits I find! Also, once you have run somewhere, you HAVE to run back to get home so I like that motivation!!

The treadmill may not be accurate for distance OR calories burned.  If you get a Garmin, it will tell you how many calories it thinks you've burned, which also may not be accurate.

I can run much faster on a treadmill, but it bores me senseless - three miles is the most I can stand.  How Runniff managed 2 hours beats me.

Get outside and enjoy the fresh air, the uphills and the downhills - which you never get on a treadmill!  Don't worry about the calories.

I cant even begin to imagine doing over an hour on a treadmill, regardless of fitness levels (which would currenlty be a problem for me) I'd feel mentally exhausted and very bored. 

After my run last night I was amazed at how much quicker the time went, I think as long as I can do at least 3.5 miles 3 times a week (to help with my weight loss) I think I'm going to start to look at miles rather than calories. 

My route last night was an "out and back" route so once I was half way through my run I had no choice on doing the rest of my run, I had to get back home.  It was weird though, coming up to the half way point I was starting to feel worn out, once I knew I was over half way I seemed to get my second wind

I know everyone thinks the treadmill is boring but I do have some killer running playlists on my ipod and I used to sort of sink into a trance, madly mouthing the song lyrics and thus probably looking quite unhinged. These days I dont use an ipod running, i find outside I feel more connected with my environment and more relaxed afterwards if I don't....

I have a treadmill at home and I've just joined the gym close to my studenty home.  They both bore me silly and there's no way I could do more than about half an hour on one, but they're useful in some ways.  If I want to do intervals, I like using a treadmill.  If I want to run downhill, I use the treadmill (knee issues = useless at hills).  If I'm coming back from being ill, I use the treadmill - that way, if I can't go any further I'm not stuck.

Running outdoors is so much more fun than watching the same spot on the wall until you run straight out of your mind.  Whatever the calorie difference is, you'll burn more calories in the long run doing something that you actually enjoy, because you'll do it more.  So do whichever one you prefer!