Although training in the cold is not always pleasant, it is possible, if you know what you’re doing. Here are some practical tips for working out on cold days.
1. Don’t be a hero.
There is no air temperature below which exercise is unsafe. Even when the mercury falls well below zero you can safely train outdoors, if you are properly dressed. However, on especially cold days the risk of hypothermia and frostbite is increased even if you are wrapped up appropriately. For example, if you encounter a situation where you are forced to stop exercising far from home (such as muscle cramping), your body will produce much less heat and you could be in trouble.
So play it safe on the most frigid days. Avoid straying too far from home and using unfamiliar routes, and carry a cell phone and a credit or debit card with you in case a problem arises. Take precautions to prevent getting wet, as the resulting evaporative cooling could send your body temperature spiraling downward. If you experience early signs of hypothermia or frostbite, such as tingling in the extremities, get inside as quickly as possible. Also, avoid running or cycling on slick surfaces such as black ice regardless of the temperature.
2. Dress appropriately.
The first rule of dressing for winter workouts is to wear technical apparel that is specifically designed for this use. These products have several advantages over cotton sweat suits, everyday winter jackets and other items that are simply warm. Winter technical apparel is made from breathable, moisture-wicking fabrics that trap just enough but not too much of the heat your working muscles produce against your skin while keeping your skin relatively dry, so that evaporative cooling doesn’t chill you. Winter technical apparel is also lighter, allows more freedom of movement, and is easier to layer than other types of clothing.
How much clothing should you wear? As a general rule, you should dress so that you are uncomfortably cool but not miserably cold when you first step out the door and then become comfortable after about 10 minutes of activity as body heat accumulates. The following table provides a basic set of guidelines for how to dress in different temperatures.
In addition to the air temperature, also consider the wind when dressing for cold-weather workouts and wear a wind-resistant outer layer if necessary. Cyclists often get themselves into trouble on cold and windy days when they do out-and-back rides in which they have a tailwind in the first half and generate a lot of sweat, then face a headwind on the way back, which rapidly pulls all that sweat off their bodies and chills them. You can avoid this problem by packing a wind-resistant jacket to put on at your turnaround point.
3. Don’t forget to hydrate.
Athletes who routinely use water or a sports drink while training in the summer heat are much less likely to do so in the colder months. There is a tendency to assume that hydration is not an important issue in cold-weather exercise. But in reality it is just as important. Failure to drink carries the same risks in the cold as it does in the heat: dehydration, bonking, and even fatigue-related injury.
Several factors increase the likelihood of dehydration in the cold. First, cold air tends to be very dry, especially at higher altitude, and in dry air more fluid is lost as vapor through breathing. Second, the cold tends to suppress thirst so that athletes drink less even when fluid is available. Third, cold-induced dieresis causes rapid fluid loss via urination, which often reduces the amount of fluid athletes voluntarily chose to drink when exercising in the cold.
To avoid dehydration in your winter workouts, drink water or a sports drink during all workouts lasting longer than an hour, even on the coldest days. Compensate for your reduced desire to drink by drinking on a schedule of four to six ounces every 10 to 15 minutes. Sports drinks are generally preferable to water because unlike water they replace the electrolyte minerals lost in sweat and provide carbohydrate energy, plus they are more palatable. Consider heating your sports drink before you head outdoors to make it even more palatable.
Active Expert Matt Fitzgerald is the author of Iron War: Dave Scott, Mark Allen & The Greatest Race Ever Run (VeloPress 2011) and RUN: The Mind-Body Method of Running by Feel. He is also a coach and training intelligence specialist for PEAR Sports. Learn more at mattfitzgerald.org.