Running in cold weather: what to wear, when to skip
Most cold runs are safe in the right clothes. Wind and wet matter more than the thermometer. How to dress, warm up and when to move indoors.
By Runapt
You can run safely in most cold weather if you dress for it. The ACSM position stand by Castellani and colleagues (2006) concludes that most cold-weather exercise can be done safely with appropriate clothing, and that wind and wet increase heat loss. So check the wind and the rain before you check the thermometer.
That gives you four decisions: what to wear, how the wind and wet change the plan, how to warm up and pace the run, and when to go inside instead. The last section turns them into steps for this week.
Dress in thin layers and start slightly cold
Layering and staying dry are the main defences against cold (Castellani et al., 2006). In practice that is three jobs: a base layer against the skin, a middle layer for warmth, and an outer layer that blocks wind or rain. Several thin layers beat one thick one, because you can take one off at kilometre 3 and tie it round your waist.
Start the run feeling slightly cool at the door. Running produces heat within minutes, and a runner who feels perfectly warm in the hallway will be sweating by kilometre 2. Sweat is the problem, because damp clothing is what turns a pleasant run into a cold walk home.
Here is an example. A hypothetical runner heads out for 50 minutes of easy running at 3 °C (37 °F) with little wind. Long tights, a long-sleeve top in a fabric that dries quickly, a light jacket, thin gloves and a hat are enough. The gloves and hat matter because the body answers cold by narrowing its blood vessels (vasoconstriction) and, if that is not enough, by shivering (Castellani & Young, 2016). You would rather not rely on either.
Wind and wet decide how cold the run feels
The same 3 °C feels very different on a sheltered street and on an open dijk with a westerly. Wind and wet both increase heat loss (Castellani et al., 2006), so they should shape the route and the clothes, not just the temperature on your phone.
Three rules that follow from that:
Run into the wind first and finish with it behind you. You are warm early on, and you are tired and damp at the end, when a headwind would cost the most.
Pick shelter over scenery. Trees, a canal path or streets between buildings take the edge off a strong wind. A running route planner lets you draw that loop before you leave instead of improvising at the first cold corner.
Put the rain shell on before the rain starts. A dry base layer under a wet shell is fine. A wet base layer under anything is not.
After the run, change within a few minutes. Standing in the car park stretching in damp clothes undoes the good work of the dressing.
Warm up inside and keep the pace easy
One reasonable option: spend 5 minutes indoors walking briskly and swinging your legs forward and back, then run the first 10 minutes slower than your easy pace. This is a suggestion, not a rule from the research. Its logic is simple: cold muscles and stiff clothing feel worse in the first kilometre, and the first kilometre is the worst moment to decide how the day is going.
Cold does not change what most of your running should be: easy. Wind, a heavy jacket and slippery ground change what a pace costs, so use the talk test, not the watch. Our post on how slow an easy run should be covers the effort side. An example: a runner whose easy pace is 6:00/km (9:39/mile) may find that the same effort is 6:20/km into a headwind. That is not a bad run. It is the same run in worse air.
The first cold runs of autumn also feel harder than the thermometer suggests. Humans show only limited, slow acclimatization to cold (Castellani & Young, 2016), so expect to keep dressing for it rather than getting used to it. Keep one quality session a week, as you would in any season, and do not add more because the shorter days make you feel behind.
Go inside when the surface or the dark makes the run a bad trade
Dark evenings are the second real problem of winter running. Wear reflective clothing and a light you can see by, add a small rear light, and run routes you know by heart. Unknown paths in the dark are how people find the one icy patch.
Set your indoor rule before you leave, because deciding at the door is how runs get skipped. A rule that works: if the path is glazed or you have to shorten your stride just to stay upright, the run moves to the treadmill. Runners can log treadmill sessions in Runapt, so the indoor run still counts toward your week.
See a doctor if cold air brings on wheezing, chest tightness or dizziness, or if your fingers or toes stay numb and pale after you warm up. Do not try to run through those.
What to do this week
Before each run, look at the wind and the rain, not only the temperature.
Lay out three thin layers, a hat and thin gloves the night before. Aim to feel slightly cool at the door.
Plan a loop that starts into the wind and finishes with it behind you.
Warm up for 5 minutes indoors, then run the first 10 minutes easy.
Decide your indoor rule now: ice, no light or a storm means the treadmill.
Change into dry clothes within a few minutes of finishing.
If ice or a storm breaks your week, Runapt can move and adjust your upcoming sessions. Do not stack the missed hard session onto the next day, as we explain in what to do when your week breaks midweek.
FAQ
Is it bad to run in cold weather?
For most people it is not. The ACSM position stand says most cold-weather exercise can be done safely with appropriate clothing (Castellani et al., 2006). If you have asthma, or you notice symptoms of cold injury such as numb, pale fingers or toes that do not recover, talk to a doctor.
What should you wear for running in the cold?
Wear thin layers: a base layer, a warm middle layer and a wind or rain shell, plus a hat and thin gloves. Aim to feel slightly cool when you start. Staying dry matters as much as staying warm (Castellani et al., 2006).
Does your body get used to running in the cold?
Only a little, and slowly. Reviews of the physiology find limited acclimatization to cold in humans (Castellani & Young, 2016). Plan to keep dressing for the weather instead of waiting to adapt.
When is it too cold to run outside?
There is no single temperature, because wind and wet change how much heat you lose (Castellani et al., 2006). Move the run indoors when the surface is icy, when you cannot be seen in the dark, or when you start shivering and do not warm up within the first 10 minutes.
Sources
Castellani, J. W., Young, A. J., Ducharme, M. B., Giesbrecht, G. G., Glickman, E., & Sallis, R. E. (2006). Prevention of cold injuries during exercise. Medicine & Science in Sports & Exercise, 38(11), 2012–2029. https://doi.org/10.1249/01.mss.0000241641.75101.64
Castellani, J. W., & Young, A. J. (2016). Human physiological responses to cold exposure: Acute responses and acclimatization to prolonged exposure. Autonomic Neuroscience, 196, 63–74. https://doi.org/10.1016/j.autneu.2016.02.009