Contributed by Dr. Steven T. Devor – Director of Performance Physiology for MIT and OhioHealth, and Associate Professor of Exercise Physiology, Department of Human Sciences, and Department of Physiology and Cell Biology, The Ohio State University
This time of year I know that many people become cautious and nervous about the cold air you breathe in while running outside, and that you are concerned your lungs were going to be exposed to very cold air and potentially damaged. Many express specific concern about the burning sensation that is sometimes felt in the lungs while running in the cold.
I want to reassure all of you that your lungs will be completely fine. The air you are breathing in when running outside this time of year, while very cold in the atmosphere, is not cold at all by the time it reaches your lungs. Let me explain what happens, and why you feel that burning sensation.
First, know that by the time breathed in air reaches the bottom of your trachea (i.e., your wind pipe) it is warmed to body temperature (98.6 degrees F) and is 100% humidified. This is true no mater what the ambient air temperature is, and no matter what the relative humidity is in the atmosphere. So there is never cold air that reaches your lungs.
The burning sensation some of you are experiencing is caused by the dehydration and subsequent irritation of the cells that line the trachea. As air is breathed in this time of year, the relative humidity of that air tends to be very low (especially when compared with the relative humidity of the air in the summer time). Remember that the air needs to be brought up to 100% humidification before it reaches your lungs.
Where does all that extra water (humidity) come from? The answer is the cells that line your trachea give up their water supply to humidify the air that is about to go into your lungs. This is not a problem if you are only outside for a short period of time in the cold weather. However, when you are outside working hard (e.g., running) and you are breathing a lot harder, those cells that line the trachea become severely dehydrated. Once dehydrated they become irritated, and you perceive this dehydration and irritation as "burning" in your throat and lungs. This sensation is not at all uncommon for those that are new to exercising outdoors in the cold weather.
There are at least two things you can do in order to minimize the feeling. First and foremost, you must stay hydrated this time of year. I know many of you might think that it is cold out, I am not really sweating all that much, so why do I need to drink for hydration this time of year. The answer is you are sweating more than you think, and if you stay well hydrated you will go a long way toward minimizing that sensation of "burning" in your trachea. The other helpful tip is to focus on deep breathing and not "panting" as much. Short quick breaths will irritate the trachea even faster.
So keep up the great work you are all doing with your running, and enjoy the beautiful crisp weather this time of year. Remember there is no bad weather, only poor clothing choices.
Best wishes for your continued training success.