Winter is approaching, but that doesn’t stop people from playing snow sports or exercising outdoors. Despite our bodies’ need to maintain a certain core body temperature for thermal homeostasis, the cold weather itself is not a major barrier to people wanting to enjoy exercise outside. Although it’s generally safe to exercise in colder temperatures, it’s important to know how cold conditions affect your performance.
Exercise and sports performance depends on several factors such as the neuromuscular system, energy metabolism, the cardiovascular system, and psychological capabilities (i.e. motivation, pain tolerance, cognitive function, etc). The cold weather affects all of these factors and thereby influences what we can do. To what extent may also be different for every individual. Regardless, you may find that exercising in the winter may not feel the same as it would during the fall, spring, or summer.
1. Your muscles must work harder in the cold
There is a correlation between muscle temperature and neuromuscular function. When muscles are exposed to cooler temperatures, the maximal contractile force of muscle decreases. In other words, your muscles must work harder to contract while nerve function also operates at a slower speed. Overall, this impacts certain muscle functions such as manual dexterity, grip strength, and reflexes. You may find it difficult to tie your shoelaces or zip up your jacket in the cold. However, you would have to be in extremely cold conditions to not have full use of your hands.
2. Your body consumes more oxygen
In terms of metabolism, acute cold stress has been shown to increase oxygen consumption in the body. VO2 max (AKA maximal oxygen consumption) is the maximum amount of oxygen your body can utilize during exercise. The cold weather causes us to use more oxygen to supply our muscles and organs for exercise. It’s also been shown that continuous exposure to the cold (about 40 deg F) results in greater metabolic heat production in response to acute cold stress at rest. What that means is over time, your body will be better at generating heat to allow you to keep warm at rest. This happens in exercise as well. Your body does a good job at maintaining VO2max (or max oxygen consumption) to keep you warm during your cold-weather exercise.
3. Your body fatigues faster
The combination of increased muscle work and oxygen consumption may result in faster muscle fatigue. You have to expend more energy in cold weather to keep yourself warm, which leaves you with less energy to work with during an exercise. In a multi-day cross-country ski race where conditions ranged from -18 to -4 deg F, only 6% of participants finished due to extreme discomfort and fatigue. The high energy cost of moving on high-friction snow (from the extremely cold conditions) caused the athletes to fatigue sooner.
4. Your heart and lungs get affected
Your heart functions to regulate body temperature by circulating blood and oxygen around your body. In cases of hypothermia (core body temperatures dropping below 95 deg F), this can lead to irregularities in the heartbeat. In cold climate athletes, it was found that the underlying common respiratory health risk factor is breathing in large volumes of cold dry air, which ultimately dehydrates the lining of your lungs. This can result in coughing, wheezing, chest tightness, and excessive mucus production.
5. Your cognitive focus gets tested
Many studies show that acute cold exposure may impair attention, speed of processing, memory, and executive function. However, acclimating to the cold over time can sometimes benefit cognitive focus, which is advantageous in sport environments. Those living and training in cold climates have an advantage compared to warm climate athletes competing in cold environments.
What should you do?
Staying active is important and you should continue to move during the cold seasons. If you plan to get plenty of exercise in the cold, here are helpful tips to prevent unnecessary injuries.
Written by Kimberly Le, PT, DPT
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