What’s not to love about training outside in the winter? Frostbite, numb hands and feet, the endless washing of bikes and salt-caked kit…

Solutions to these challenges are pretty straightforward - cover exposed skin, invest in some winter riding gloves and shoes, keep a rag and chain lube handy for the end of your ride.

We can bundle-up to insulate our core and extremities, but what about our lungs? Read on to learn how cold and dry air can impact our respiratory system.

The main function of our lungs is to replace carbon dioxide (CO2) with fresh oxygen (O2) in our bloodstream - this process is called respiration.

As we inhale, our lungs expand and fresh air travels through smaller and smaller passages called bronchioles. In those passages, fresh air moves across the surface of microscopic balloon-like sacs called alveoli.

At the alveoli, oxygen enters the bloodstream while carbon dioxide is removed - this is called gas exchange. The efficiency of gas-exchange impacts the rate of oxygen delivery to muscles, among other things.

Colder and less-humid air can negatively impact the rate of gas exchange in two main ways: the passageways in your lungs get smaller (bronchiolar constriction), and alveoli and other parts of your respiratory tract begin to dry out. The end result is less air moving through your lungs AND a decreased rate of gas exchange.

Some tips to consider when training in the cold:

Cover your mouth and nose to help keep inhaled air more humid.
Stay on top of hydration (even if you’re not sweating that much).
Consider doing harder, high-intensity workouts indoors, where it’s easier to control temperature and humidity.

Explore more:

Read: Winter Training Tips from TrainingPeaks

Watch: Ted Talk: How Do Lungs Work by Emma Bryce

Listen: Interview with Iditarod 350 Bikepacking Race Winner Neil Beltchenko

Cold Weather & Your Lungs