Dressing for running in winter can seem like a challenge if you haven't done any similar type of winter exercising before. During my first winter trail running season, I wasn’t sure if I could even run in the winter. In this article I tell you everything about my winter running favorites and what I wear trail running in the winter.

The best thing about winter running is that the familiar running paths turn into new ones when the white snow covers the landscape. Trail running in the dark with a headtorch adds even more excitement. When you run far enough away from the city lights, you can sometimes admire a brilliant starry sky or even the northern lights when running in the northern latitudes.

In the first winter, I tested all kinds of outfit combinations for running, sometimes more and sometimes less successfully. In trail running, it's a bit the same as in hiking: what works for someone else, doesn't necessarily work for you. However, certain basics, such as dressing in layers and wearing running shoes with a good grip, are suitable for everyone.

Read my tips on what to wear for winter running, whether you run to improve your fitness or you just run for fun!

What to wear when running in the cold?

Dressing for winter running can be a huge challenge, because the weather in the Nordic winter can vary from freezing temperatures to freezing rain and slush to mildly sunny and warm winter days.

It may sound like a hundred pieces of clothing just for winter running, but a few good pieces of equipment will do great, when you dress in layers.

In all winter sports, including winter trail running, you should prefer layered clothing. Layering is based on three basic layers: base layer, mid-layer and outer layer. The idea of layering is that you can either add or remove a layer and combine the same clothes in different ways for different weather.

By the way, it doesn’t have to be 'running clothes' or ten fancy technical terms on any piece of clothing. Most of the clothes you use in winter for outdoors or other winter sports are suitable for winter running, too. The most important thing is the material that works in the cold.

However, when you get hooked in trail running, you might want some equipment just for running. When you invest in great and durable equipment, you really don't need to stock up on new winter clothes every year.

Layered clothing for winter running

The base layer is one of the most important layers of winter clothing. Its function is to keep the skin dry by moving moisture. Both a technical layer and a merino wool layer are moisture-wicking and suitable for winter running.

• Icebreaker's 260 g merino wool base layer is both warm and pleasantly soft. It's also warm, so I use it only when it's really cold. When it's warmer, I use thin merino tights that I use on summer hikes under my running tights and some thin merino shirt or a thick running shirt as a top.
• When running in the winter, I prefer to also wear merino wool underwear and a merino wool running top, which do not feel disgustingly cold and wet at any point during the run. Other people prefer technical materials when running, for me merino wool is the most wonderful material for outdoor clothing.

The mid-layer is an insulating layer for winter exercise. It warms and protects from cold. The material of the mid-layer that comes on top of the base layer is good to be breathable. Fleece and wool work best.

• Light and thin mid-layers are suitable for winter running. The mid-layer should preferably be loose enough to function in the best possible way. My favorite mid-layer is Rab thermal fleece or Salomon winter fleece running jacket.

The most important function of the shell layer is to protect against rain and wind. A light and breathable jacket with a cut suitable for active movement is best for running. In winter, choose the shell layer according to weather: if it's freezing, you don't need a raincoat, and if it's sleeting, it's not too cold.

An extra layer means a layer that brings extra insulation. In winter running, for example, a break quickly cools the sweat, and an additional layer is necessary. For example, a light down jacket or a down vest can be used as a thermal layer.

Running tights in winter

Winter running tights are warmer than summer running tights. You can find great options by googling "winter running tights". Winter jersey is thicker fabric, usually with a brushed inner surface.

• On warmer winter days, you can get by with just winter tights, but in severe frosts (-10 °C and colder) you should put on merino tights or other thermal tights under the winter running tights. The close-fitting base layer warms you up and doesn't feel uncomfortable under the close-fitting running tights.
• I have found my favorite women's winter running tights from Endurance and Craft. Both feel great on, but the Endurance tights also have pockets big enough for a cell phone and other stuff. The Craft running tights jerseys frayed from the crotch in one winter, but the Endurance tights show no wear.

I've also considered having warm and lightweight shorts over running tights, but so far, the idea has not progressed beyond the idea level.

If your legs feel too cold in tights when it's cold, you can also use leg warmers. Any wool leg warmers will do. Leg warmers are easy to knit yourself!

For winter running, you can also use looser running pants. They work like a shell over a close-fitting base layer. I think loose running pants somehow feel clumsy, so I only wear tights.

Running jacket for winter

Southern Finland's winters are often mild and with little snow, but sometimes you can run in deep snow and freezing temperatures. When you have invested in a good and warm base layer, a thinner jacket is oftentimes enough.

• My standard equipment for milder and dry winter weather is a Salomon fleece winter running jacket and a merino wool undershirt (Icebreaker, Tierra, Devold or Super.Natural) or a thick Endurance technical shirt for winter running. I also use all merino wool shirts on hikes and other outdoor sports.
• In sleeting weather, with temperature close to zero, the most effective combination is a warm merino wool base layer and a waterproof jacket as an outer layer. You probably don't need an insulating mid-layer. Depending on the wind, I pull on either a hooded loose Patagonia Storm Racer Jacket or a flexible OMM Kamleika shell jacket.
• At twenty degrees below zero, you probably need one extra layer. The combination that works best for colder temperatures is a warm merino wool base layer, a warming fleece on top (e.g. Rab high-collar thermal fleece is really good), and a light and breathable jacket as the outer layer.
• Instead of fleece, a merino wool t-shirt over the underlayer can also be enough. It depends on your own experience of the cold, at which point you need a warming mid-layer and how thick the clothing should be.

I have also tested a Tierra softshell jacket I bought for winter hiking, in trail running in winter. The softshell jacket is surprisingly warm, so you shouldn't put it on in very mild weather. It's also a tad too heavy for running. A softshell works best in freezing and windy weather, because it keeps the heat inside and blocks the wind.

It might not be a good idea to wear a light down jacket for a run, even if the air feels cold. If you run even a little so that your heart rate rises, you will start sweating a lot. A wet down jacket feels awful.

On the other hand, if you don't have time to warm up at home before going for a run, you can wear a warm down jacket, down vest or fleece at the beginning of the run, and then take it off as soon as you feel warm.

When you go on a long run in the winter, a light down jacket that packs into a small space is the best break jacket. If you stand for a long time in the middle of a run in the winter, the sweat freezes and you freeze quickly, too. Rapid cooling and the risk of hypothermia should be taken into account when planning a longer trail run in severe frost.

Keep your head and fingers warm

When running in winter, it's important to keep your head, fingers and toes warm, because these places sweat the most and are most prone to freezing.

• In mild winter weather, thin Inov trail gloves are enough for me. I also use them in autumn and spring. In severe frosts, I change the thin gloves to thicker thermal gloves from Black Diamond, which I often take with me on hikes.
• A combination that works in severe frosts is also thin merino wool gloves and thick mittens on top of them. Sometimes I also use padded Hestra gloves, which are mainly part of my equipment for snowshoeing or skiing trips.
• As a headgear in light frosts, I use either a merino wool bandana or a running beanie made of a mixture of merino wool and silk. In mild weather, even a thin beanie usually makes my head sweat, so the headband works best as ear protection.
• In severe frost, a thicker merino wool beanie is fine. I use for example Fjällräven basic merino wool beanie, which is suitable for everything from everyday life to outdoor sports.

In extremely cold weather, it is good to also protect your face and airways. For example, Buff merino wool tube scarf or balaclava (commando beanie) are great, especially if you have got asthma.

The downside of holding a tube scarf in front of your mouth is that it gets wet from your breathing and starts to feel uncomfortable at some point.

Trail running shoes for winter

Good grip is essential in winter running shoes. Trail running shoes are basically good for winter running, as they usually have deep and complex lugs that guarantee great grip.

• I have tested a regular Asics running shoes, Saucony Peregrine 10 trail running shoes, as well as Hoka Speedgoat 4 and 5, Evo Speedgoat and ATR Challenger trail running shoes in cold weather and on ice. The regular running shoes work OK if it's not slippery. But, even on a slightly slippery surface, a regular running shoe slips all the time.
• Saucony trail running shoes could be good for winter, but the model does not feel good on my feet when running. The last is a bit narrow, and there is not enough room for the toes to wiggle. Sauconys have become my day hiking shoes, for which they are perfect.
• Hoka trail running shoes have worked excellently in winter. My favorite is the Hoka Speedgoat, which works in all terrains and weather conditions. Hoka has good cushioning and a loose toe section. They also have very deep lugs on the soles, and the grip is enough for almost everything except icy snow and ice.

Is it worth getting winter running shoes with studs? I can't answer this, because I'm in love with Hoka Speedgoat, and I've never considered changing the shoe model. I got separate traction device for Hoka's instead. In winter running, studs are necessary if you run on icy paths and rocks.

• For example, the Nortec Trail Micro Crampons are attached to the running shoe by pulling it on the shoe, so you can run in the same running shoes in the winter as in the summer. Nortec micro crampons are extremely light weight and they got excellent grip even when running on hard ice. The feeling is amazing!
• Otherwise, I've been really satisfied with Nortec crampons, but in one winter they wore out the cover of my Hoka trail running shoes, and in addition, one cable broke for some reason. My running shoe was a bit between sizes compared to the traction device’s size recommendation, so a one size larger traction device might not have torn the fabric so badly. I plan to fix my Nortecs and further test them in the near future.

In muddy weather, Gore-Tex trail running shoes would probably be the most comfortable, as normal trail running shoes get wet in the slush. However, I haven't missed waterproof shoes either, because you don’t have to run in that slush puddle. If you're a fan of dry feet, consider waterproof trail running shoes for winter.

Your feet and toes won't freeze even in summer running shoes, when you wear merino wool socks in cold weather. I have used and tested running socks, e.g. from the following brands: Smartwool, Salomon, Stoic, Bridgedale, Revolution and Devold. Salomon's socks (two pairs) have unfortunately broken in use, although otherwise they have been comfortable.

• My personal favorites for cold weather are probably the padded Smartwool Women's Run Cold Weather Targeted Cushion Crew merino socks. (Here's also an example of unnecessary terminology to make the winter socks sound more professional!) The socks have very plush padding at the toes and a reinforced heel.

If you do a lot of (trail) running, you probably own several running shoes. Tip: get two different sizes of running shoes, normal size for summer and half a size bigger for winter.

• Half a size bigger doesn't feel much bigger, but in the winter the running shoes can fit thick and warm socks and still leave a little more room for the toes to move. I wear trail running shoes half a size bigger even on long summer runs and ultra-distances, when the foot may swell more.

If you run in snow, you should wear a gaiter over the ankle to prevent snow from getting into the shoe. In running shoes, the snow melts and wets the socks from the ankles, which feels unpleasant in the cold.

Do you need a running vest in winter?

Just like in summer, you don't necessarily need a running vest for short runs in winter. However, a running vest or a running backpack has its advantages: you can easily carry a headlamp, tissues, a thermos of hot juice and a warm fleece shirt just in case. It's especially annoying to leave a headtorch at home if the run takes more time than you anticipated and you don’t reach home before it’s dark.

• The spacious Salomon ADV Skin 12W women's running vest is great for winter. The back part can hold a one-liter Thermos bottle upright, as well as change clothes and a foam pad under the butt, in case you happen to take a break in the woods during your run. The vest also comfortably provides additional protection from the wind.
• Even a smaller running vest is enough for warm winter days, when you don't have to carry a thermos bottle with you. My own Salomon Advanced Skin 8W running vest has been great year-round. Both vests can fit a change shirt and a shell jacket that can be packed small.

When it's dark, it's important to remember to be visible: use a reflector. Also, always carry a headtorch, as darkness falls quickly, and you may misjudge your speed in a snowy forest.

Running in winter – cold weather and slower pace

Winter running is at its best good fitness maintenance and beautiful winter scenery. Especially in winter, you don't have to try to break records. The calm pace is gentle on the lungs and airways, so winter running may also be suitable for asthmatics.

I have mild asthma, which reacts most to strenuous exercise in cold air. Winter trail running is easiest when I move with sufficiently low pace.

In terms of what to wear when winter running, it's good to remember that in lighter training in the winter you should dress a little warmer than when you are running at race pace.

On the other hand, a slow pace in the winter can mean a very heavy workout if you trail run in deep snow. Since you can have various level of pace during the same run, it's nice to have an extra layer in your running vest that you can add and remove as needed.

When running in cold air, you may not notice the feeling of thirst the same way as in summer, even though winter exercise makes you sweat and the body requires fluids in the same way as in summer, or even more.

Pack hot juice in a small thermos and cool water in another soft bottle. My own bottle has never frozen in freezing temperatures, so I haven't acquired any special winter hydration system.

Also take some snacks with you for a winter run, which does not get frozen in the cold. Chocolate stays soft when you put it in your pocket close enough to your body, so do gels and honey.

What could be a more wonderful running experience than a peaceful long run and a cup of hot blackcurrant juice with a gingerbread in a snowy winter forest!

Read also: Trail running in winter - 10 best tips for winter runners