The cold temperatures and blistery winds that often accompany winter running usually get a bad rap among the running community, but it can truly be a welcomed thing after months of sweating it out in the humidity and heat of the warmer, summer months. If you properly bundle up and safely avoid extreme temperatures and conditions, winter running can actually be quite enjoyable! But it does pose some dangerous threats to your health and so it is extremely important that you take the proper precautions to make sure your bones, joints, muscles, and lungs stay healthy.
First off, your body does not warm up as fast when it is cold outside. That means that it takes a longer amount of time for your muscles to become loose and safely flexible, which is important for lengthening your stride and running faster to reach your goal times. The more flexible your muscles are, the faster they will warm up so consider taking an extra couple of yoga or pilates classes during the winter to increase your flexibility and mobility. And then when its time to run outside, be sure you give yourself at least a few miles to warm up before you attempt any difficult speed, tempo, or hill workouts.
Logistically, time your runs during the winter so that you avoid darkness which usually means even colder temperatures, as well as exposes you to the threat of black ice patches which can lead to some nasty injuries. And always dress appropriately. Wear protective head gear and clothes that protect your extremities, which are the most prone to frostbite and getting too cold. And don't forget the right socks and shoes! Not only do you need thicker socks (wool is the best option!) and shoes, but you need to make sure the bottom grip of your shoes can handle ice, snow, and other rough terrains. Dress in layers and keep your core warm. That will help regulate your body temperature better. So opt for a vest or jacket, preferably wind proof if possible. Happy winter running!
Sources
https://www.runnersworld.com/ask-the-sports-doc/how-to-stay-safe-while-running-in-the-winter
https://www.runnersworld.com/race-training/winter-injury-proofing