Hungrier? Exercising in much colder temperatures

This has happened several times this winter: I seem to get hungrier faster when I exercise outdoors in fairly cold winter temperatures. ie. temp. colder than minus -18 degrees C. Whether it's cycling, snowshoeing or simply hiking for a few hrs.

Yesterday we hiked in a park for only 7 km. in fresh snow 20 cms. deep @ temp. -23 degrees C. We were famished but discovered a nice restaurant in the park was closed for lunch. By the time we found store, I gobbled up a chococlate cookie within 2 minutes. :confused:

I'm beginning to believe that exercise in quite cold winter temperatures, simply burns off abit more calories....even simply by just standing around for half an hr. Wonder if someone has done a study on this..

Yup, I think it's pretty well established that cold surroundings cause your body to burn more calories to keep warm. I don't think you can completely compensate by dressing more warmly, and even then the extra clothing alone makes it a bit more of an effort to move. And there's only so much you can do to warm up cold air entering your lungs anyway. I'm not sure how much of it is automatic, and how much of it is simply the cold stimulating you to move more, though.

I wonder if it's not just your body burning more calories, but maybe the cold air stimulates hormone production and appetite increase independent of calories burned. It would make sense that we should have an instinct to consume more calories in cold weather, both to compensate for the increased energy expenditure and to increase insulation.

I read an interesting study that was pretty conclusive that you *do not* burn significantly more calories when it is cold, but cold does affect your appetite. If I'm remembering correctly cold doesn't stimulate hormone production that increases appetite, but rather decreases the effectiveness of hormones that suppress appetite.

The study was done by having people exercise in a cold pool or in a warm room. After exercise both groups were offered a selection of snacks. The cold pool group, I think, may have burned slightly more (I don't totally recall), but they also consumed more than the warm room group - significantly more, and definitely more that would have simply offset any additional calories expended by being cold.

Moral of the story was... watch your eating after exercising in the cold -you will feel more hungry than you really are!

I'll see if I can find the actual study. It was some time ago and I had I think, a PDF copy. I haven't been able to find it out on the web... It was quite interesting.

Would be useful Eden. Of course, the temperatures we were very cold (it is close to frostbitten face warning situation) vs. what someone living in Florida experiencing just freezing temp.

Or maybe a person' body acclimatizes over the years in northern climates, that their body would burn calories more slowly to "conserve"....similar to body adjusting to less food in general during periods of near starvation??

Nevertheless it nearly scared me on 2 separate occasions: Yesterday and last weekend I knew I couldn't cycle an extra 5 km. after a 30 km. ride in -15 degrees C weather...I desperately needed some food energy. Just a small amount of food, that's all. In the summer I wouldn't be hankering for food in this way.

I always feel like I burn a lot more calories in the cold. The first winter I cycled a lot, my weight dropped and I had to force myself to eat more.

There could have been other variables, and I didn't keep track of mileage. It's possible I traveled farther when I wasn't stopping to watch birds, chat with friends, etc.

Although my appetite does increase from long, hard rides in the warm weather, I do notice this much more at this time of year. Last Saturday, I did a measly 8-10K x country skiing, and maybe another 8K of snow shoeing. I was famished the rest of the day, despite eating a sandwich for lunch and a Luna Bar. I tried fighting it, but did succumb to a couple of healthier type snacks.
Perhaps this is why my weight is up a little. I am ravenously hungry...

Of course there is a link between appetite and cold weather. The unit "calorie" is used for the amount of energy needed to HEAT 1 gr of water by 1 kelvin. You can be sure that you need more energy to keep your body warm in winter. My coach said to increase the food intake by 10% in cold weather. But we do not ride in SUCH cold weather. Maybe when it's -5 or 0, but more than that...I use the trainer :)
Your body is telling you that it needs more energy, don't neglect its signals :)

Pretty sure that is actually that is incorrect.... You don't burn significantly more when it's cold. I haven't found the full study that I read yet, but here is a summary of one that is, if not the same one, similar.

Many people feel extremely hungry after immersion in cold water. As a result they simply replace all the calories they’ve burned with a large post-exercise meal, completely wiping out any potential weight loss benefits of the swimming.

In a University of Florida study, a group of men exercised for 45 minutes in both neutral (33 degrees Celsius) and cold (20 degrees Celsius) water temperatures. They were then allowed to eat as much food as they wanted.

The men burned a similar number of calories in the cold and neutral water conditions, averaging 505 and 517 calories, respectively. However, calorie intake after exercise in the cold water averaged 877 calories, which was 44% more than for the neutral temperature.

Granted the 10% your coach recommends isn't a huge amount more intake, but certainly much more than the difference in what was observed, which was only around 2% more, 10-12 calories, not 50.

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Originally Posted by shootingstar

Nevertheless it nearly scared me on 2 separate occasions: Yesterday and last weekend I knew I couldn't cycle an extra 5 km. after a 30 km. ride in -15 degrees C weather...I desperately needed some food energy. Just a small amount of food, that's all. In the summer I wouldn't be hankering for food in this way.

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Sounds like reactive hypoglycemia, to me. It's one reason I do really well on low carb diets. High carb = incredible blood sugar yo-yos and irrational hunger.

That's an interesting study, Eden! But I'd venture the idea that exercising for longer periods of time in cold weather is slightly different. 45 min isn't very long, and for the record, 20 deg C is considered excellent bathing temperature over here... ;)

But the study makes sense anyway. In cold climates, carrying a little extra fat is probably what evolution considers a really good idea. So maybe the stimulated appetite is to get you to eat a bit more and add a little insulation, so that you can survive the cold for longer. It would be interesting to see if people carrying extra body fat in the first place had the same appetite hike or if it plateaus once you better equipped to manage the cold.

I've done some longer skiing trips in cold weather, and I especially craved fatty foods after a day or two, not sugar.

At one point in time I did find something much more comprehensive.... they went into the details of why you get more hungry too, the processes that were being disrupted. You do burn a bit more in the cold, but that was the key - it wasn't that much more and not nearly as much as you *feel* like.

I'm not sure the time would really make too much of a difference -I'd guess the percentage more energy expended wouldn't change too much -though it may change another 1 or 2 percent or so for each 10-15C lower the temps go maybe? It would have to get pretty darn cold to get to a 10% extra calorie burn.

I'm not sure I'd survive winter in Norway these days... I've got too acclimated to this relatively neutral climate... It's around 0C here today and I find myself with little desire to go outside :rolleyes: In college we lived in a place with cold, cold winters. I remember putting on all of my warm clothes to go out cross country skiing when it was something ridiculous like -60F with the windchill. Sounds more than intolerable to me now.

I have not read these studies but when we camped in 0 degrees we all ate before getting in our sleeping bags to "stoke the furnace" as our A.T. guru told us to do (: I have never needed a snack before sleeping outside when its warm.......

I think there's a big difference between being sedentary in cold weather (when your body needs to generate heat to stay warm) vs. strenuous exertion (when it's still throwing off heat to avoid being overheated, just not as much as we do when it's warm).

It's probably a remnant of evolution that we're hungrier when it's cold - when we had nothing but our own and each other's body heat to keep us warm, we needed the extra calories.

I've sure experienced the "ravenous after swimming" thing.

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Originally Posted by zoom-zoom

Sounds like reactive hypoglycemia, to me. It's one reason I do really well on low carb diets. High carb = incredible blood sugar yo-yos and irrational hunger.

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Hey zoom-zoom, the reason why I ate cookie after the hike, was that I won a scratch n'win card that entitled me to a free bag ....of Christie cookies. We didn't know the neighbourhood to find shops/place to eat. So took transit and got off to use my freebie card at the sponsoring grocery store near home. I had to make good use of that cookie bag! :p Better to have that 1 cookie in moments of near desperation just after exercise, instead of 4 hrs. later ....because I really was desperate.

Before the winter snowy hike, I had a breakfast of cornflakes with milk, fruit, etc. No, I don't eat bacon or an egg often at all for breakfast. I never thought hiking on primarily a FLAT route would induce this type of hunger on a very cold winter day. He had a bottle of water. Dearie and I have gotten lost in that urban park before, which is 15 km. long with only 1 restaurant/cafe...which was closed this season. To get to street level, would mean another hike of at least 2 km. up a 18% steep hill (the only steepness in this route) and then you end up in the suburban residential area, not anywhere near a restaurant or even a donut shop until another 4 km. away.

(Why people want to live so much further away from services, shops --it definitely is not my style of living.)


For certain, feeling weak while outdoors and not immediately close to a store or place with food during very cold winter, is definitely not the same as feeling weak while in the summer or spring when it's warmer or hot. At least if you faint/collapse, you won't get hypthermia...

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Originally Posted by shootingstar

Hey zoom-zoom, the reason why I ate cookie after the hike, was that I won a scratch n'win card that entitled me to a free bag ....of Christie cookies. We didn't know the neighbourhood to find shops/place to eat. So took transit and got off to use my freebie card at the sponsoring grocery store near home. I had to make good use of that cookie bag! :p Better to have that 1 cookie in moments of near desperation just after exercise, instead of 4 hrs. later ....because I really was desperate.

Before the winter snowy hike, I had a breakfast of cornflakes with milk, fruit, etc. No, I don't eat bacon or an egg often at all for breakfast. I never thought hiking on primarily a FLAT route would induce this type of hunger on a very cold winter day.

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Yeah, if I ate a breakfast of pure carbs with minimal fat and/or protein I'd be one hot, desperate, cranky, shaky, nauseous mess (my family has several stories of me "going postal" when hunger hit fast and hard). YMMV, but there are few people who don't at some point run into issues after a light breakfast of high glycemic foods followed by extended activity.

This is hiking and cycling just within my own home city. I tend to eat much larger breakfasts with egg, etc..when away from home and going snowshoeing in the mountains.

Well, I certainly forgot to bring some food. (which again for this small distance on bike in summer, fall, I don't bother.)

I did notice for myself, that when I did eat a large breakfast at the hotel. Then off snowshoeing for 2 hrs. in the mountains, I did feel appropriately....."empty" at the end of the trip, without being hungry.

People living in our area.....go 1,000 km. north to work in the winter, at the oil tar sands and oil rigs near Canada's Arctic Circle. Just to give people an idea here, how "tough" locals can be...and their willingness to work under such conditions outdoors in the winter. So the coldness in our area, is like practice for them... I continue to be amazed to see how thinly dressed some cyclists and joggers are. In my head I'm thinking: They must be born in this area...not a transplant like me.

When I cycle in winter @ -10 to -20 degrees C, I am definitely cycling alot slower --at least 25% slower. There's no real reason to cycle fast in such cold wintery temperatures. So definitely I am not sweating it up like some joggers or cross-country skiers and expending alot of calories every half hr.

I was thinking about this thread today. I went XC skiing for about 3 hrs in -18 deg C, warmer in the sun of course when we could find it, but probably down to below -20 deg C in the coldest spots. The trip started with at least half an hour of strenuous uphill skiing, and I had to take off one wool jersey. I was quite comfortable, ie. warm but not sweating for a long while wearing just mesh wool underwear covered by a thin windproof jacket and PI Amfib tights (and hat, buff+lobster gloves) but as the terrain leveled out to gently rolling the cold started creeping in. First my chest got cold, then it crept down my arms and I could feel a finger or two growing cold. Finally I had to stop and put the jersey back on, only 3 kms from the cabin where we were going to stop for food, and was fine again.

I didn't actually eat any more than I would have done when at home, but I felt the need to eat earlier, and not get hungry. Getting hungry means getting cold and weak, weak means having trouble generating heat, which means even colder. I enjoy both biking and skiing when it's cold, but I find I have to be more careful about eating protein and fat-rich food in advance, I have to stay "stoked up" on food, and I have to avoid sweating a lot, either by moving a bit slower or by removing excess clothing early enough. None of these things matter much when it's above freezing.

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didn't actually eat any more than I would have done when at home, but I felt the need to eat earlier, and not get hungry. Getting hungry means getting cold and weak, weak means having trouble generating heat, which means even colder. I enjoy both biking and skiing when it's cold, but I find I have to be more careful about eating protein and fat-rich food in advance, I have to stay "stoked up" on food, and I have to avoid sweating a lot, either by moving a bit slower or by removing excess clothing early enough. None of these things matter much when it's above freezing.

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Most definitely, when I stop to drink or eat something small ...or go to the washroom in the great outdoors while snowshoeing in the mountain wilderness, I do want to make any rest stop briefer than I would in warmer seasons: it's just colder!! I feel my vulnerability and need to be vigilant to keep moving, when it's quite cold in the winter. For certain at -20 degrees C in winter, I have to dress more warmly than you lph!