From snow and ice to sub-zero wind chills, winter running presents several difficulties to runners. Each winter, I receive dozens of questions on winter running, including how to dress, if you can acclimate, and what shoes to wear. This article provides answers to all your common winter running questions.
Remember that each runner is an individual and will respond to cold weather differently! Above all else, prioritize your own safety and comfort.
How cold is too cold to run outside?
At a certain point, cold weather poses physiological risks. You may have a higher risk of muscle strains in the cold, particularly during speed workouts. Additionally, the risk of hypothermia and frostbite increases. While the choice is ultimately individual, -5 degrees windchill is a point where it may be too cold to run safely outside. (This article delves more into how cold is too cold to run.)
Will I acclimate to cold temperatures?
Yes – but not quite in the same way you acclimate to the heat. (Cold acclimation does not give a performance boost at more mild temperatures.) Recurring exposure to the cold will increase cold tolerance. So, a temperature that feels uncomfortable to run in now may feel more tolerable later. Think of how 40 degrees feels cold in autumn and then pleasant in the spring!
Is it normal to run slower in the cold?
Yes -both at maximal and submaximal intensities. According to a 2022 study in Medicine and Science in Sports and Exercise, every 1-degree Celsius (1.8 degree Fahrenheit) drop below 10 degrees Celsius (50 degrees Fahrenheit) causes a 0.3-0.4% decline in performance. Around 0-20 degrees Fahrenheit, the cold weather causes approximately a 5% reduction in performance. (See more here about what happens to your body when you run in cold weather.)
Do I burn more calories running in the cold?
Unless you are shivering due to low body temperature, you will not burn more calories running in the cold. When you do shiver, the combined increase in active energy expenditure, catecholamine release, and thyroid action will lead to a two- to fourfold increase in metabolic rate – because your body is trying to prevent hypothermia. Do not deliberately underdress on runs to burn more calories, as the risks of hypothermia are higher.
My legs are red and super itchy after a run in the cold. Why is this?
The red, bumpy, itchy skin that happens when you jump straight into the shower after a cold run is called chilblains. Chilblains occur when the blood vessels constrict too much due to the cold and then inflame as they warm back up, causing itchiness and redness for up to an hour. Chilblains are unpleasant, but they do not cause any long-term effects.
Warming up too quickly can worsen chilblains – meaning that jumping in the shower immediately after a run may actually make the symptoms worse rather than better. Based on personal experience, I’ve found that changing into warm dry clothes immediately after a run and then gradually warming up before showering decreases the occurrence of chilblains. The best course of action is preventative: wear warm, wicking gear on your winter runs (see below).
My hands turn purple and lose dexterity when I run in the cold. How can I avoid this?
Cold weather causes blood vessels to constrict. During exercise, your body prioritizes circulation to the core and working muscles, meaning that you have less circulation in your hands. The combination of the cold weather and change in circulation from exercise means you are not getting as much blood flow into your hands. Without sufficient blood flow, you experience a loss of dexterity, purple/blue hands, and numbness, followed by redness and pain upon rewarming.
If your hands frequently change colors and lose dexterity, you may need to dress more appropriately. Some runners prefer mittens to gloves, since mittens can hold in more heat between the fingers. Others find that layering gloves under mittens works well. I know several runners who use handwarmers on very cold days!
Severe cases of this are known as Raynaud’s Syndrome; exercising in the cold can exacerbate the symptoms of Raynaud’s. What can prevent the symptoms of Raynaud’s? Keep your hands and feet protected from the cold. Warm, wicking socks on your feet, mittens on your hands (mittens keep your hands warmer than gloves), and hand/foot warmers on very cold runs will provide a protective layer from the cold and keep your extremities warm and dexterous. If you are prone to Raynaud’s in your feet, wear compression leggings or compression socks to promote blood flow to your feet.
How should I dress for winter running?
You want to dress warm enough to avoid hypothermia, while still accounting for the metabolic heat you will generate during runs. Additionally, you want to cover as much skin as possible to mitigate hypothermia risk. When dressing for winter running, be mindful to check the wind chill (which factors in wind speed as well as temperature).
Depending on the temperatures, these are the key pieces of gear for winter runs:
- A good base layer
- A quarter-zip or other mid-layer
- A vest or a jacket
- Hat or ear warmer
- Neck warmer or balaclava
- Merino wool socks
This article delves into a more detailed breakdown of what to wear for running in cold weather. Read more here for specific suggestions for winter running clothes and gear.
If you live anywhere that gets snow or ice, I highly recommend trail running shoes. Yaktrak and nanospikes work well on thick layers of snow and ice, but if your route varies between clear pavement and snow/ice, you risk ruining the crampons and being uncomfortable for parts of the run. Heavily lugged trail shoes provide the traction you need on snow or ice and transition comfortably to plowed surfaces.
How do I run in icy conditions?
Ice can be dangerous to run on. You can easily lose your footing and slip, which could cause a muscle strain, bone fracture, or even a concussion. If you have the option, run on the treadmill. If the treadmill isn’t an option (or you really despise it), rearrange your training plan so you cross-train that day. Trails or gravel paths can provide an alternative since they are less likely to be as dangerously icy as roads. However, always assess individual conditions.
If you must run on ice, wear the appropriate footwear (heavily lugged trail shoes or a traction device designed for the ice) and do a short, easy-paced run. Do NOT do a speed workout or a long run. Be willing to walk through very icy patches.
Alternatively, you can also cross-train with winter-specific sports! Snowshoeing and cross-country skiing can provide aerobic training stimuli in conditions that may not be conducive to running.
Housh, Housh, and deVries. (2016). Applied Exercise and Sport Physiology. (4th ed.) Holcomb Hathway Publishers.