Does external temperature affect cals burned?

I'd be curious to know this also lol as my gym can't seem to regulate the temperature inside the gym lately with all the crazy weather outside lol

I've wondered that too - seems like keeping warm when exercising on super cold days would burn more, but I have no idea.

@cnsmith - love your profile pic!

Honestly, I can't see it affecting anything more than marginally. You would burn more calories at rest in a colder environment, but when you're exercising, your body isn't focused on keeping you warm, because generally, exercising means that your body has switched to "cool-down" mode, and is worried about dispersing heat out, and not keeping it in.

In warmer weather, I think the only effect is exhaustion from overheating, but that's because your body gets overwhelmed by its attempts to keep everything cool enough. I don't think it literally burns more calories, because it's not working "harder"; it just can't keep up with demand.

Don't know for sure, though, but I really think it's pretty marginal.

It does burn more calories to keep your body warm, so working out in the cold is helpful. However, you are more prone to injury when doing rigorous exercise in the cold, since your muscles stay so tight. The difference between the two is pretty minimal (about 2% from what I have read), so I don't really concern myself with it. Being a bigger guy, I enjoy cooler temperatures more. Alot of the places where I have seen this referenced are actually talking about what you are exposed to all day. Your body will burn extra calories over the entire day if you environment is a little cooler (below 70 F), even if you aren't exercising.

Do you have an HRM? Could you test it? Maybe walk outside (if it's colder) for 20 minutes and then inside somewhere for 20 minutes and compare? Just an idea

When I do my workouts at home I always make sure to turn off the fans and air because I find I sweat more that way so I figure I must be burning more fat since there is more sweat. I know Tracy Anderson suggests you workout in a hot room.

When I do my workouts at home I always make sure to turn off the fans and air because I find I sweat more that way so I figure I must be burning more fat since there is more sweat. I know Tracy Anderson suggests you workout in a hot room.

You burn more fat when glycogen is depleted. That wouldn't matter if it was hot or cold.

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I seem to recall a Canadian Armed Forces study from some years ago that suggested the difference was statistically insignificant. The one thing to be aware of when running long distances in extreme cold is hydration, you lose a fair bit of water through breathing (same thing that faces scuba divers - very low humidity air) and, as the frost on my fleece layer often attests to, you still perspire freely in cold weather.

When I do my workouts at home I always make sure to turn off the fans and air because I find I sweat more that way so I figure I must be burning more fat since there is more sweat. I know Tracy Anderson suggests you workout in a hot room.

we burn just a bit more calories when it's cold outside because our bodies work a little more to adjust to the external temperatures.
working out in a hot room makes you lose water so, as soon as you drink water/eat after your HOT workout, you'll gain that weight back

**Warning: Possible Bro Science incoming. I dont have any official proofs or links to the publications I have read this, I just vaguely remember reading about this and felt like sharing**

From what I've read, yes, body does try to warm up your external temperature. It will however try to warm up your internal temperature before it'll try to do that for external as a defense mechanism. This is why its said to drink ice cold water, since your body have to warm up that water and raise the waters temperature (proof, you never pee out that ice cold water). So, albeit negligible, your body does burn more calories trying to keep itself warm. HOWEVER, it'll also burn calories trying to keep itself cold. Sweating, like anything body does including breathing burn calories so obviously sweating to cool off your body burns calories too.

Now the question comes in, wether to workout in hot temp or cold. I have read its better to do it in hot temp. Mainly because during a decent workout, your body is warm itself and the cold temperature will not make an affect on it to try and keep itself warm. However, if the room temperature was hot, and your body is also exerting heat, then your body will try and cool itself more (which in a cold room, it'll have less to do) and hence you endup burning more calories in a hot room.

Accordng to an article on livestrong, you burn more fat in higher temperatures.
http://www.livestrong.com/article/373028-does-exercising-in-hot-temperatures-burn-more-fat/

I loved the disclaimer someone put about "bro" science. I guess what I'm going to say here is the same thing, except maybe it is "sis" science LOL.

If it is hot you will back off to keep from overheating … thus burn less calories. If it is cold you can hurt something because your are tense. If it is cool you can work out harder without overheating or injuring yourself, thus you burn more calories. Does it need to be extremely cold? No, just allow you to be comfortable. Will you sweat? Well of course you will. You know you will sweat if it is cold and you are working out. Don't go to extremes not too hot and not too cold. If you are working out outside, you can't control your climate, but you can control when you do it. So workout when it is cooler and not at high noon in the warmer weather. In the colder weather workout when it is warmer. Personally I kind of find this common sense.

So external temperature will affect cals burned, only in that it will effect how intense you are able to workout.