Why does running in the cold slow you down

yeah running in the heat blows. I'd say around 30-60 is ideal; above and below that it gets harder to maintain a given pace

I think some people are missing the point of the question. The question is not what is your cold tolerance. If your are comfortable running at 20 degrees then answer what would slow you down in 0 degrees, if you are comfortable at 0 degrees then what would slow you down at -20, and so on. The question is what are the physiological reasons that the cold slows you down (whatever cold means to you)?

good runner's world article on this:

http://www.runnersworld.com/article/0,7120,s6-238-267-269-12331-0,00.html?cm_mmc=training-_-2010_01_12-_-training-_-TRAINING%3a%20Cold%20Weather%20Running

It does affect you as the air is colder it makes it harder to get in large amounts, also with having so many layers of cloths it limits the range of motion. i.e shorter stride length.

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RunGambit wrote:

I brought this up before but nobody has explicitly commented on it. What about the fact that in colder weather your body has to expend energy keeping your core temperature constant. Does anyone think this slows you down?

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Class of 73: The core, yes, but I also think that a certain amount of energy (calories) is expended by the body's effort to keep the extremities warm, also.

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common wrote:

[quote]Mr Mountain wrote:
That is absolutely not true. The cold air irritates your bronchial tubes. It takes a lot of energy to spit and blow your nose all the time when running in the cold.

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trevor dunbar wrote:

http://www.youtube.com/watch?v=8eXqAWjJ_dE

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Mr Mountain wrote:
If the air wasn't cold where I live, it wouldn't be dry so my bronchial tubes wouldn't be irritated. If the air wasn't cold, it also wouldn't make my nose run which was the main point (even though it was actually a joke because we all know blowing your nose wouldn't slow you down that much.) I will admit I spit in the summer, just not as much in the winter.

I would be more than happy if you could let me know where to find extremely cold HUMID air and I would go there to run in the winter.

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runnerMATON

When you inhale, air is pretty much at body temp at the point of oxygen exchange. Besides, what do the lungs have to do with oxygen being efficiently transfered to the cells in the muscles. Nothing. If you are experiencing hypothermia then I can see your point.

I hear a duck.

i recently finished a master's in exercise phys.

for the nerds out there:

http://www.ncbi.nlm.nih.gov/pubmed/7258827?dopt=Abstract

so we have evidence of bronchoconstriction during exercise in subfreezing, about 27 fahrenheit, temperatures...i haven't yet found evidence of whether this inhibits pulmonary diffusion capacity, leading to less than 100% arterial oxygen saturation. i am aware that a subset of elite athletes (and also some people with pulmonary disease) experience a limitation on performance due to pulmonary diffusion capacity (too much blood flowing too fast through the lungs which doesn't allow enough pulmonary residence time for full saturation of the blood with oxygen), and i would imagine that exercise in cold temperatures such as around zero fahrenheit (-17 celsius or so) would exacerbate this problem.

however i did also find this article which suggests an inhaled beta 2 adrenergic agonist (bronchodilator) doesn't improve performance of well-trained individuals in the cold, suggesting that any existing bronchoconstriction doesn't pose a significant limitation.
http://www.ncbi.nlm.nih.gov/pubmed/17316372?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=10

to echo some things said earlier in the thread: i definitely think some people mentally deal with the cold better than others. and it would be ridiculous to suggest that everybody physically deals with the cold the same: the aforementioned bronchoconstriction no doubt happens to different degrees in different individuals.

not sure if the combo of humidity and cold has been mentioned, that would likely play a role as well.

also habituation plays a role to cold response. for instance people exposed to cold temperatures for several hours a day repeatedly over a couple weeks have less of a shivering response and generate more heat from non shivering thermogenesis. other nuances of habituation to cold temperatures may differentially influence people's ability to perform maximal exercise in the cold.

to the guy that said his performance wasn't affected much in 94 degree heat. B.S. try running that same 5k in 55 degrees (without generating a bunch of hubbub, 55 is supposed to be close to ideal running temperature...there are actually equations that fairly accurately predict performance decrements for endurance events for every degree fahrenheit above 55...i.e. if you're training for a sub 3 hour marathon in good conditions and it's 75 degrees on race day, maybe 3:05-3:10 is a reasonably altered goal).

ok i think that's it for now. i don't feel like looking up more nerd articles.

You would have to restrict your airway very significantly to lose enough volume of oxygen to affect performance. While I believe it is a legitimate from a mechanical basis (reduced inspired volume = reduced 02sat = reduced output...if you've ever run wearing a facemask or two, you know that restricting your airway will create an oxygen debt at slower paces), this mecahnism of restriction (failing a full on bronchial spasm) is not going to decrease inspired volume to a degree that will reduce performance.

Interesting thought, though. Long live the nerds.

in response to common, probably true considering that under normal conditions, expired air is still about 16% oxygen (down from 20.94% ambient oxygen), meaning you only put about a quarter of the available oxygen into your blood.

in response to the core temperature thing, what i've learned is that mostly regardless of ambient temperature, whether hot or freezing, assuming proper clothing, workload (pace) is the primary determinant of core temperature. meaning haile G has a hotter core during a marathon than joe blow, even if haile decides to casually run 5 minute pace and joe blow is turning blue in the face from struggling through 9 minute miles.

your body, while running, in my understanding, does not expend much energy to either heat or cool you. in the cold, with proper clothes, the workload keeps you warm. in the heat, sweating (evaporative cooling) gets rid of excess heat. this does not require caloric expenditure or oxygen consumption. what it does do is reduce your blood plasma volume. this in combination with superficial (skin) vasodilation means you've got less central blood volume. your heart's stroke volume declining means your heart rate has to speed up to maintain the cardiac output necessary for your workload. so if you decide to, say, jog for 2 hours at 7 minute pace in the heat, your heart rate might be 140 after 30 minutes but 160 by the end. normally heart rate will increase mostly linearly with workload, but in this case workload is constant and heart rate increases cause sweating and vasodilation has decreased stroke volume. it's called cardiovascular drift.

the real problem is exercise in the heat PLUS humidity. then your two main avenues for heat dissipation - convection (airflow) and sweating - are mostly gone. my undergrad ex phys prof would say "at 95 and 95, stay at rest to stay alive." meaning if it's above 95 degrees F (close to body temp) and 95% humidity - DO NOT TRY TO EXERCISE, as your body will continue to retain heat from the workload until, well, you die. the end. literally.

[quote]lonacus wrote:

to the guy that said his performance wasn't affected much in 94 degree heat. B.S. try running that same 5k in 55 degrees (without generating a bunch of hubbub, 55 is supposed to be close to ideal running temperature...there are actually equations that fairly accurately predict performance decrements for endurance events for every degree fahrenheit above 55...i.e. if you're training for a sub 3 hour marathon in good conditions and it's 75 degrees on race day, maybe 3:05-3:10 is a reasonably altered goal).

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I actually said ". I ran a 5k a couple summers ago that was 94° and only felt it cost me a few seconds per mile"

I have run hundreds of races in all sorts of temps so I know what I am talking about for ME. While the heat would certainly be a detriment in a longer race, I don't feel it affected me at all the first mile, some the second mile, and my head was about to explode at the finish. Since it was such a short race, I don't believe I could have run 20 seconds faster in optimum 50°-55° weather. I just ran a 5k in 35° weather and didn't feel it affected my time at all. Running in 20° weather (windchill 10°) did affect my time a lot. Again, that is just my experience. I actually have a rule that I won't race over 5 miles when it is very hot but if you are well hydrated and pace yourself properly, a 5k is no problem.

The point was that I would much rather run when it is uncomfortably hot than when it is uncomfortably cold. Others may differ.

For me personally, anything much below 35 starts to have an effect on my pacing, especially when it's windy. I have bradycardia and VCD (vocal cord dysfunction) so that's probably the main cause for my increased struggling in the cold. I get cold easily and I'm not able to warm up during runs (even with 3 jackets on, as I experienced the other day). (And it's not because I'm not running hard enough, I'm a female averaging around 7:30 and below for my runs)

This video made me tear up hahaha