Cold-air effect on Oxygen

there is some daniels type calculator that gives you equivalents at different altitudes and temps..it is what it is..whatever I run at altitude, sea level, cold, hot is what I run on that day..

the concentration of o2 is always ~20% its just the pressure that changes but I'm no "geologist' like some others up here..

Well, running in cold weather is not like running at altitude. In fact, if you run in weather that is cold enough, it can cause serious scar tissue in your lungs. Now, it is true that it is more difficult to breathe when the temperature is very low, but that is not related to low oxygen levels, rather the body's increased blood pressure and the heart working harder to maintain a reasonable core temp.

In essence, it is probably a better idea to run indoors on a treadmill when the temp is around 0-10 degrees. You aren't going to get a good aerobic stimulus running outdoors anyways.

This stuff about scarring lungs must be an old wives tale. I've run with lots of people in Wisconsin in below zero weather and none of us have ever had (or even heard of) any lung problems. Sources please?

yeah, think about how far into your body air has to travel to get to your lungs. I imagine that it would be warm enough not to do any damage by then. Wouldn't you get scar tissue in your mouth and throat way before the air has much of an effect on your lungs?

When I was training in Michigan people would tell me that, but I just can't imagine that it's true.

There are some tables somewhere I have about temperatures where it is dangerous to exercise heavily, but for the most part this whole scar tissue idea isn't a reasonable explanation.

Oxygen in the air is going to be the same percentage, hot or cold, and actually even at altitude! At altitude, it is the change in the partial pressure of oxygen which changes, not even the percentage itself. One major difference is the air generally is less humid with cold temperatures.

Individuals with asthma are especially responsive to this. If you seriously struggle with cold air compared to most others in the same conditions, you may need to get evaluated. However, from experience working with a top-notch asthma researcher, there are many doctors who misdiagnose asthma, and a dry air challenge test must be performed or else the diagnose may be missed.

Also, the fact about blood pressure being higher and heart working harder doesn't quite work either. Most people going out in extreme cold are going to be dressed warm. Any there are plenty of us that have gone for a run in the cold and come back quite sweaty, just because we dressed warm-enough. Therefore, maintaining a core temperature is not an issue of the heart in this case, but rather the clothes we wear. In fact, the heart is actually working harder in the heat, and heart rate is higher then.

During exercise, heat is produced as a by-product, through friction of muscle contraction and through chemical reactions within the cell - which is why we get warm with exercise. The body has numerous mechanisms of getting rid of this heat, and one is dilating the blood vessels of the skin. This allows more of the warm blood to come closer to the surface of the skin and be cooled by the air surrounding the body (assuming it is cooler). Hence, our veins stick out more when we exercise in the heat. Since more blood is being diverted to the skin, cardiac output has to increase for the same absolute amount of blood to get to the muscles. This is compounded by sweat, which basically is water that will in the end be lost from our blood stream, giving us less blood to pump through our system. So, all of this results in increased heart rate during exercise in the heat for a given intensity. It is a bit more complex than that, but you get the point.

The proportion oxygen is not affected by temperature. The density of the air IS affected by temperature. (The effect is appreciable: pilots of small planes have to be aware of temperature/density because you need more runway to take off on a hot day.)

So yes, cold are holds more oxygen per unit of volume (which is what matters) even though it holds no more oxygen per unit of mass.

Right you are on density--however, the difference is actually appreciable--why do you think that cars that are designed for high performance have intakes that take in air temperature air rather than engine compartment temperature air?

Figure that I ran in -4F degree temps today and you ran in 86 degree air--a difference in density of around 10%. If I could handle running fast at this temp--I would have 10% more O2 per breath than you. Add into that the fact that I am breathing dry air and you are breathing humid air (comprised of water + air) and the affect would be even greater.

http://www.engineeringtoolbox.com/dry-air-properties-d_973.html

as the temperatures at different temps. For those who don't know, -273 C is = -462 F.

I agree with sc42. Aviation has a term, density altitude, which refers to the lower density of air at higher temperatures. So I think there would be less 02 per liter when it is hotter. This would seem to result in slower times at summer temperatures even if you ignore the added stress of keeping the body cool. But i don't really know

There is more O2 per liter of cold air, as mentioned above. But if your muscles get cold enough, the hemoglobin in your muscles will hold on tighter to the O2 that it has carried from the lungs, effectively delivering less to the muscles. Not sure how much of an effect this has, but I doubt it is much of anything in ambient temps above 15 degrees. I notice a huge effect on my running when it is -20 or colder, but I'm slow to start with. And no, my lungs have no problem, though I wear a balaclava when the weather is below 0 because otherwise my throat gets sore.

you are right - it is not "just like altitude training" - obviously your friend is not a scientist nor has he ever been to altitude.

Another factor in the cold is that blood will tend to be focused on the core and the brain to warm it, thus some is not made available.

Hemoglobin gives up oxygen better in a warmer environment (Bohr effect). There are graphs in just about every ex phys book showing the curve so there is some decrease in performance.

A warm muscle also works better so muscle function is going to be a bit impaired.

I cannot believe people who exercise really still believe the myth about lung damage. Now it can certainly feel harder and when I was running last week in single digit (F) temperatures sucking in the cold air did not feel great, but there has been no damage from my 4 years in WI/IL and 10 years in Colorado.

"Not going to get a good aerobic stimulus running outdoors". Classic. What actually happens then?

The lung scarring is NOT an old wives tale. However, you need to be regularly performing at a hard race effort in order for cold air to scar your lungs. Just doing base work and even fairly hard running is not sufficient to damage so there is no need to take to the treadmill.

The proof is in the obvious scarring that is seen in the lungs of cold weather racers. Sled dogs and Nordic skiers show this damage. You don't necessarily feel this damage.

hey,

ya, so I have certainly noticed it is easier to run and do aerobic activities in winter, (live in Canada), I always assumed it was due to increased partial pressures.

In terms of the lung-scaring, I'm happy I've been informed about it, since I have noticed sometimes if I'm running or biking very hard (like sprinting up hill) and it is -10C or below then I can smell/taste blood after.

However I have managed to avoid that happening by wearing a scarf or balaclava so that I only breath in air that was pre-warmed within it. for instance with a half-balclava I have it goes up tight around the the nose and air comes in around the throat, so it has time to warm up.

Can make it slightly harder to breathe but it's worth long term lung health.

Elspru wrote:

hey,

ya, so I have certainly noticed it is easier to run and do aerobic activities in winter, (live in Canada), I always assumed it was due to increased partial pressures.

In terms of the lung-scaring, I'm happy I've been informed about it, since I have noticed sometimes if I'm running or biking very hard (like sprinting up hill) and it is -10C or below then I can smell/taste blood after.

However I have managed to avoid that happening by wearing a scarf or balaclava so that I only breath in air that was pre-warmed within it. for instance with a half-balclava I have it goes up tight around the the nose and air comes in around the throat, so it has time to warm up.

Can make it slightly harder to breathe but it's worth long term lung health.

I mean no offence but how old were you when the previous response was posted?

I think that was one of my worst year's as a runner.

Well, I think you get more air/ oxygen in the cold 10-45 degrees,oppose to the warm weather 60_90 degrees. In warm temperatures, the air is thick, almost like there's no air at all.when you out there running your body heats up pretty fast. So in the warmer weather it's like your body temperature collides with outside air temperature. Which there is not much of, making it difficult.i believe it's also depends on the individual and their health. Personally I like running in the cold. I get a better result. It takes me 80 mins to run 10 miles in the Cold and 90 mins when the temperature is up. Infact in the summer time I have difficulty completing 10 miles. Sometimes it could take me 100 mins. Again the air is pretty thick.