The Science of Cold-Weather Running


Dan has a PhD is Exercise Physiology from Penn State University, a 2:26 marathon PR, and is currently a Postdoctoral Fellow in the Integrative Physiology of Aging Laboratory at the University of Colorado Boulder. He also happens to be a good friend of mine, and on long runs, he always has interesting scientific info to share as the miles fly by. He is no stranger to as he wrote a guest blog called Train Hot Race Cool and now he is back with more insight on how climate affects running.

Cold temperatures are on the way for runners all over the country. While humans are very good at acclimating to hot weather (we increase our sweat rate and skin blood flow), we are relatively poor at acclimating to cold weather. Because of this, cold weather poses a unique challenge for runners. Here, I’ll tell you why the cold slows you down and what you can do about it.  

One way the cold temperatures can negatively influence your running performance is by decreasing muscle force production. Cold muscles contract with less force than warm muscles. The cold also changes the neural recruitment pattern of muscle fibers (basically, the brain changes the way it signals muscles to contract), which results in less efficient contractions and further reduces muscle force. This means you’ll have to increase your effort to maintain the same pace, which isn’t ideal for performance-oriented runners. How can you counteract this? First, do a dynamic warm-up (lunges, squats, clamshells, donkey kicks, etc.) indoors before going out and running in the cold; this will increase muscle temperature and blood flow. Second, wear running pants or tights when the temperature drops to near- or below-freezing levels. Sure, it might look tough to run in shorts when it is zero degrees out, but you don’t get a bonus in races for being a dumbass.

Another way the cold can affect your running is by changing metabolism. In the cold, your body uses fewer free fatty acids and more glycogen for energy. In long races, like the marathon, running out of glucose and glycogen results in hitting the wall. So, in cold weather you’re likely to hit the wall a few miles sooner than in warm weather. Be sure you start your run well fueled by eating plenty of carbs in the preceding 24 hours. Also, be sure you are fueling during any long run or race in the cold. Drinking too much cold liquid while running can lower your body temperature, so I recommend using gels or chews that can be carried with you and kept warm by your body heat (note: you’ll still need to drink enough to maintain hydration, however this will be much less than what is required when it’s hot outside).  

To summarize, in cold weather be sure you:

1.     Do a dynamic warm-up

2.     Dress in warm clothes

3.     Consume carbohydrates 

Do these three things and you’ll be ready to conquer to cold weather and your competition.

Cold weather fun fact: Ever wonder why you have to pee as soon as you go out in the cold? The cold causes vasoconstriction of the blood vessels in your periphery, which redistributes more blood to your core, including the kidneys. The increased blood flow to the kidneys increases urine production, which makes you pee.

Happy Running!