Q: Am I at greater risk of muscle or joint injury when I exercise in the cold?
A: In general cold-weather workouts are almost always safe, as long as you bundle up (layers are key) and pay extra attention to slick, slippery surfaces. But what's happening inside?
Cold weather certainly can increase your risk of straining or tearing something. That's because the lower temps cause our muscles to tighten a little bit more.
Think about a block of clay that's been sitting there, that cold block of clay would tear if you stretched it, compared to how pliable it would be if you spent some time warming it up in your hands first. Our muscles and connective tissue also have less elasticity when the temperature gets lower.
That's why warming up is more important now than at any other time of year. In average temps when you're not using your muscles, most of your blood flows to your internal organs. When you start to call on your legs and arms to get moving, blood vessels open up to fuel those working muscles, but when the mercury drops, you're amplifying that effect. If you jump right into a sudden, powerful movement such as sprinting on a stiffer-than-normal muscle, that force could lead to injury.
The cold may also slow down some of our sensory mechanisms. When your nerves are colder, there's slower transmission rate, making, say, your feet a little numb, which could throw off your balance. It's possible then to be doing damage without being totally aware of it: In warmer weather, you might read a twinge of pain as a signal to ease up; in cold weather, you might push yourself through the twinge toward injury.
The good news is cold-weather exercise injuries are preventable. If you're dressed appropriately for the weather and you do a gradual, proper warmup, you can avoid a lot of that. Look at the warmup as literally warming up the muscles, tendons, and other parts of your body to get ready for the greater forces that you'll be applying to them in sprinting, jumping, or landing.