Sub-freezing temperatures require some changes of plan for your regular runs and for racing. Following are some helpful tips for staying safe if it’s cold, damp, and/or windy out. With the right clothing and adequate precautions, even single-digit weather can be comfortable for runners.

• Wear synthetic fabrics and layer your clothing. In the cold, keep most of your body covered. The fabric closest to your skin should be synthetic and preferably sweat-wicking and it should fit snugly. (Running tights are ideal for the waist down.) Your outermost layer should be wind-resistant and waterproof if it’s raining or snowing. Ideally, your clothing should be able to adapt as you warm up, or as the weather does: Unzipping a jacket, pushing up your sleeves (or removing arm warmers), rolling up the edges of a ski-style hat, and/or putting your gloves into a pocket will all keep you in the temperate zone as you get into your run—and they’re all reversible if it’s evening and you’re running into cooling temperatures. If you plan to race, it’s smart to test everything that you plan to wear in advance to make sure it’s warm enough and comfortable to race in.
• Protect your face, head, and extremities. Wear a hat and gloves, preferably of synthetic, wicking material, and in extreme cold, use a face mask or scarf to cover your neck and face. Wind increases the effects of the cold; you may risk a mild form of frostbite called “frost nip” on unprotected areas if it’s near-freezing and windy. Apply a sweat-resistant sport moisturizer and lip balm for extra protection. Apply petroleum jelly to any spots prone to chafing or chapping.
• For a race in the cold—and especially if it’s wet out—pack warm clothing in your checked bag. Make sure that you pack dry socks, warm sweatpants, a long-sleeved shirt, a sweatshirt and/or jacket, gloves, and a warm hat. You’ll be very glad to have these things after you finish a race in soaked running clothes if the weather is near freezing.
• Stay warm before the race. If it’s really cold, bring a discardable sweatshirt to wear after you’ve checked your bag. If rain is in the forecast, bring a large-size plastic trash bags with you to wear as a throwaway raincoat. A thorough warm-up jog will get you to the start ready to go.
• As always, respect your limits. Cold temperatures restrict blood flow, which can cause muscles to contract and even cramp. You may feel stiff and tight, especially as you begin a run, and if you try to force the pace, you may damage a muscle. Adjust your pace to allow your body extra time to warm up.
• Know the signs of hypothermia and frostbite. Hypothermia occurs when your body temperature falls below 95 degrees; symptoms can include confusion and uncontrollable shivering. Frostbite occurs when circulation is restricted in the extremities (fingers, toes, ears, and nose); symptoms can include feeling numb or turning white or blue. Pay attention to your body while you run and watch for these symptoms.
• Don’t forget to drink. In cold weather, it’s easy—and unsafe—to overlook your fluid needs. Your body is still sweating, so replenish your fluids appropriately. The rule of thumb during exercise is to drink when you feel thirsty and no more than one cup (8 ounces) of fluid every 20 minutes. While racing in the cold, slow down a bit more than usual at drink stations to avoid spilling liquid on your gloves. In sub-freezing temperatures, the water in the cups can form a thin layer of ice at the top. Squeeze the cup slightly to break this layer, then drink.
• Shorten your stride in snow, ice, sleet, or heavy rain. If there is snow, ice, or excessive water on the ground, shorten your stride slightly and pay attention to your footing and the runners around you to avoid accidents. Ice creates a much greater danger of a slip-and-fall, which can send you to the hospital with a broken bone. If you race in this kind of weather, don’t expect to run a personal best; instead, plan for a safe race.
• Take care of yourself after your run. Get inside right away; although you’ll feel warm just after finishing, those wet clothes will chill quickly, and so will you. At a race, try to get out of your wet clothes and into your packed dry outfit after you reclaim your checked bag. Keep moving, and get inside as soon as you can.

With a little bit of extra forethought and planning, the winter can be a great season for runners—no treadmill required.