How to stay warm while exercising outdoors: 16 expert tips for running, hiking and swimming

Bathe in glory on a properly prepared for winter wild swim. Photograph: Ella Foote/The Guardian

There’s a glorious smugness that can only be experienced by exercising outdoors in winter conditions. The fresh air, the endorphins, the reduced risk of heart disease – they’re all nice bonuses, but nothing beats that knowing nod from another rain-drenched runner, or the horrified faces of nearby dog walkers as you stride confidently into the sea for a winter dip. There’s only one catch. In order for that intoxicating feeling to exceed the very real sting of the cold, you’ll need to make sure you’re suitably layered up.

Whether you’re running, hiking or outdoor swimming, there’s some sage advice that applies across the board: “Always start by checking the weather forecast,” advises Richard Shepherd, purchasing director at mountain sports retailer Ellis Brigham. “What you wear should match the conditions you’re likely to experience. It’s the key to staying safe and comfortable outdoors.”

We tapped up three experts, as well as yours truly on hiking, to get their top tips for keeping warm outdoors this winter.

***

The best winter running gear

Dressing for winter runs is tricky. It can feel freezing when you first step outside, but it won’t be long until you’re working up a sweat. Getting it right is a fine balance that comes with experience – something of which Nick Harris-Fry, co-founder of the Run Testers, has plenty.

***

Be bold, start cold

“Remember that you’re not just dressing for the start of the run. It’s easy to put too many layers on because you need the encouragement to get out the door, but it only takes a few minutes of running to warm up. Opting for two or three thin layers instead of one or two thick ones can help with this, because you can take a layer off once you’ve warmed up.”

***

A good base layer is key

“A good base layer will keep you warm without overheating or getting clammy, and, unless you’re braving extreme conditions, will often be the only layer you need under a jacket or top. Base layers should be soft on the skin and made from quick-drying, odour-resistant fabrics, such as merino wool.

“Tracksmith’s Brighton base is comfortable and surprisingly warm given how lightweight it is. It also dries quickly and resists odours. I use it regularly through the autumn and winter months.”

Men’s Tracksmith Brighton base layer

£100 at Tracksmith

Women’s Tracksmith Brighton base layer

£100 at Tracksmith

***

A proper waterproof jacket might be overkill

“For most people, a windproof, water-resistant jacket will probably be a better buy than a full waterproof. They’re cheaper, more packable, more breathable, and fend off showers pretty well in my experience.

“But if you’re heading out for longer runs on trails or in more remote areas, then a waterproof jacket is invaluable in offering extra protection from the elements. Many off-road events, especially ultramarathons, will require that you have a fully waterproof jacket in your backpack, because of the protection they offer if you get stuck or lost.

“The Asics Road packable jacket is windproof, water-resistant and packs away into its own pocket if conditions change or you find you’re getting too warm on a run.”

Men’s Asics Road packable jacket

From £56 at Sports Direct £89 at Asics

Women’s Asics Road packable jacket

£71.19 at SportsShoes £89 at Asics

Our pick: Decathlon Kiprun windproof running jacket

Men’s, £19.99 at Decathlon Women’s, £19.99 at Decathlon

For more, read our guides to the best waterproof jackets for men and for women

***

Insulated outerwear for only the coldest of runs

“I’m a runner who’d always rather be too warm than too cold, and I have enjoyed using an insulated jacket in temperatures below 2C this winter, but I wouldn’t say it’s essential. I don’t think insulated jackets are that common for UK runners, but you see them a lot in northern Europe and parts of the US where sub-zero temperatures are common. Personally, I’d be on the treadmill in those conditions!”

***

Sleeves are overrated

“The piece of kit that gets the most use during my winter training is actually a running gilet rather than a jacket. It’s the perfect layer for running because it keeps your core warm and blocks wind without any real risk of overheating, even on faster runs. And if it gets seriously cold, you can pop it over your jacket as an extra layer.

“Saysky’s Clean Pace Flex vest is a windproof gilet that keeps my core warm without feeling restrictive or too hot during winter workouts.”

Saysky Clean Pace Flex vest

£55.49 at Footshop

Our pick: women’s Adidas adi365 running vest

£40 at Adidas £40 at Next

For more running essentials, read the best running shoes for men and women

***

The best winter hiking gear

With fluctuations in elevation come changes in conditions that can happen quickly and be extreme at times. Being able to regulate your body temperature and protect yourself from rain, snow and wind can turn a horrible ordeal into a pleasant day out. As an outdoor-gear fanatic who writes on the matter regularly, I have some non-negotiable rules when it comes to dressing for winter hikes, and Ellis Brigham’s Shepherd has a few pearls of wisdom to share too.

***

Layers, layers, layers

When it’s cold enough to make you think twice about leaving the house, throwing on the biggest coat you can find seems like the sensible thing to do. But remember, you won’t be standing around – you’ll be moving, most likely working up a sweat, and you need to be able to fine-tune your clothing accordingly.

Being able to adjust your layers “will allow you to maintain a steady temperature whether tackling a steep ascent, resting at the summit, or speed walking to make it back before sunset”, says Shepherd.

***

Start with a solid foundation

“Base layers are the first items of clothing you wear over your underwear, next to your skin,” Shepherd says. “They wick sweat away from your body and help regulate your temperature. For hiking and other active outdoor sports, look for moisture-wicking materials such as polyester or merino wool. The former is lightweight, durable and easy to care for, while the latter is a natural fibre that’s odour-resistant and will keep you warm even when wet.”

Personally, a merino base layer is the first thing I reach for when dressing for winter hikes. Look for one that fits nice and snug, hugging the torso rather than draping over it. There are dedicated brands, such as Icebreaker and Smartwool, that specialise in this type of product and charge a premium for it. They’re great, but I also have plenty of excellent merino base layers I got from bargain bins at various outdoor shops, or even from the middle aisle at Aldi. Mountain Warehouse’s merino base layers in particular have proved to be phenomenal value for money. I’ve been using them for many years, and they’re often reduced to less than £40.

Men’s Mountain Warehouse merino base layer top

£34.99 at Mountain Warehouse £29.50 at Amazon

Women’s Mountain Warehouse merino base layer top

£34.99 at Mountain Warehouse £32 at Amazon

***

Add insulation accordingly

“The primary purpose of a mid-layer is to add warmth,” says Shepherd. “Options vary from simple fleeces to insulated down hoodies, and you can layer them together to trap extra heat. Down insulation offers the highest warmth-to-weight ratio, making it superb for cold, dry conditions and weight-conscious activities. Ask yourself, do you want something lightweight, or do you need maximum warmth? A full-zip for easy access, or a helmet-compatible hood? What about pockets? Narrow down what’s important to you and go from there.”

When I’m heading into the hills in UK winter conditions, I usually like to have two mid-layers with me – a lightweight down jacket I can pull out when I’ve stopped for a bite to eat, and something lighter and more breathable that works either on its own or layered under a shell when I’m on the move. Montbell’s EX light down anorak has been a favourite of mine this winter. It’s extremely lightweight, and I’m a big fan of the pullover design. The kangaroo pocket is great for thawing painfully cold hands too – something I appreciated immensely on a recent trip when I accidentally packed the wrong gloves.

As effective an insulator as down is, it is ultimately an animal product. There are plenty of synthetic alternatives, but they tend, in my personal experience, to be less durable over time and aren’t particularly great for the environment. Unfortunately, this leaves you with a bit of an ethical toss-up whichever path you choose.

I am, however, a longtime advocate of Arc’teryx’s synthetically insulated Atom hoodie, which I’ve been using for well over a decade now. It’s warm enough to take the sting out of the cold, but breathes well when I’m working hard. It has a trim fit that works nicely underneath a shell, too.

Montbell EX light down anorak

£405 at Montbell

Men’s Arc’teryx Atom hoodie

From £207.89 at Cotswold Outdoor £260 at Arc’teryx

Women’s Arc’teryx Atom hoodie

£181.89 at Cotswold Outdoor £260 at Arc’teryx

***

Block wind and rain with a shell (but make sure it fits)

“Most hiking waterproofs are made with room for mid-layers to be worn underneath, so you can wear your usual size,” advises Shepherd. “However, function will play a part too. A shell designed to be ultralight and low bulk will usually have a slimmer fit, and you’ll need to adjust mid-layers accordingly. Likewise, winter hiking jackets or mountaineering shells often have a more generous cut to fit insulated pieces underneath.”

I’ve tested and written about waterproofs for the Filter for two years running now, and I’ve been consistently impressed by Montane’s jackets. The British brand’s Torren shell has been my go-to waterproof since it launched more than a year ago. It’s not cheap, but waterproof jackets that will actually deliver on their promise to keep you dry rarely are.

Men’s Montane Torren waterproof jacket

£255.95 at Outdoor Action £300 at Montane

Women’s Montane Phase waterproof jacket

£244.89 at Cotswold Outdoor £350 at Montane

Read our guides to the best waterproof jackets for women and the best waterproof jackets for men

***

Don’t neglect your lower half

It’s common for people to focus on their top half and forget about their legs, but your lower half needs insulation too when it’s cold out. A pair of merino leggings serves the same function as a base layer, trapping heat and keeping the body at a stable temperature. I have a few pairs from Craghoppers, which were relatively inexpensive and have had my back for everything from dog walks to ski trips.

“You’ll want some thick socks too,” adds Shepherd. “Heavyweight merino-wool hiking socks are ideal. If you want extra warmth, choose a longer length sock that can cover your calves. I’ve been using Smartwool’s Hike full-cushion merino socks almost exclusively for several years now (the very first pair I bought are still going strong). They have padding in all the right places without adding too much bulk around the ankle. Nice and warm in the winter, but the natural temperature-regulating properties of the fabric mean I can use them in summer too.

“Over the top, opt for soft-shell trousers. They’re typically made from stretchy, windproof fabrics that let you hike comfortably while helping block wind chill.”

It’s worth carrying a pair of waterproof trousers in your pack just in case it gets wet and windy. I like Berghaus’ Deluge 2.0 trousers. They’re not the most breathable on the market, but they’re affordable, comfortable and perfect for throwing on in emergencies.

Smartwool Hike full cushion crew socks

£18.89 at SportsShoes £16.96 at Amazon

Men’s Craghoppers merino base layer leggings

£35 at Craghoppers £39.95 at LiGo

Women’s Craghoppers merino base layer leggings

£30 at Craghoppers £30 at Decathlon

Men’s Berghaus Deluge 2.0 waterproof trousers

£80 at Berghaus £56.21 at Amazon

Women’s Berghaus Deluge 2.0 waterproof trousers

£59.99 at Nevisport £75 at Decathlon

Don’t miss the hiking essentials that walkers never leave at home

***

The best cold-water swimming kit

Getting into the sea or a lake will always be cold. That’s simply the nature of the beast. But according to outdoor swimming expert (and editor of Outdoor Swimmer magazine) Ella Foote, there are plenty of things you can do to take the edge off. And, contrary to what you might think, it’s not all about what you wear during the activity.

***

Look after fingers and toes

“Neoprene gloves and socks can make a cool dip or swim much more enjoyable,” says Foote. “I don’t swim without them in winter. Our fingers and toes are pretty much just bones and ligaments with very little fat, so they can feel painfully cold in winter. When you wear neoprene gloves and socks, you can lengthen your time in the water.

“I didn’t realise how good these ones were until I felt how cold my swimming pal’s hands were when wearing a different brand. Look for a snug fit – too loose, and they will fill with water, which will affect your swimming and cancel any thermal benefits. Measure yourself and use the online size guides.”

Fourth Element neoprene gloves

£60 at Fourth Element £58 at Amazon

“These neoprene socks are thick enough to protect feet from shingle and rough terrain while also keeping your feet warm.”

Two Bare Feet 5mm neoprene socks

£15.99 at Two Bare Feet £17.99 at Amazon

***

Get your core temperature up

“Make sure you’re warm before you get in. If your core body temperature is toasty, the overall experience will be better. I would recommend investing in a decent thermal top and leggings made from merino wool or something similar. Smartwool’s thermal base layers offer comfort, warmth and natural fibres, which still work when wet.”

Women’s Smartwool women’s merino base layer

£39.97 (including membership) at Go Outdoors £73.47 at Blacks

Men’s Smartwool women’s merino base layer

£80 at Blacks From £56.05 at Amazon

***

Layer up afterwards

“Have your clothes ready in the order you’ll put them on when you get out. Your body temperature will continue to drop even when out of the water. We call this the honeymoon period. Despite feeling great and high on life, you need to dry and dress quickly, not chat and take photos. Have your coat or robe right at the bottom, and pants and thermal layers on top. You don’t want to be fumbling around when you can’t feel your fingers.”

***

A wetsuit might not be necessary

“Wetsuits provide extra buoyancy and will soften the overall chill, but they won’t make that much difference when it is 5C or under. You can also get cold trying to get them on and off. Swim your swim and learn how your body responds to cold and conditions. There are some great hybrid suits that cover the back of the neck and arms, which can reduce wind chill, but a swimsuit is often enough for short swims.

“Yulex is a sustainable, plant-based alternative to traditional neoprene that offers the same thermal benefits. This suit keeps off the chill, but the panelling enables great use of movement for proper swimming.”

Zone3 Yulex long-sleeve swimsuit

£87.50 at Decathlon

***

Cover your head

“A neoprene hat or bonnet is brilliant if you’re doing proper head-down swimming and will ease brain-freeze. Again, our heads are big bulbs of bone, so when submerged in cold water, you’ll feel it. If you’re doing a short dip, most swimmers choose to keep their heads up out of the water, so a decent bobble hat – some offered now are waterproof – can keep the chill away. Choose natural fibres such as wool, and it will still keep warm if a bit wet. Or have one for swimming and one for after – I recommended the beanie below from British brand Finisterre, in my guide to swim essentials for the Filter.

“This waterproof hat from Sealskinz has aTeflon coating that makes water bead up and roll off the surface, so if you get slapped by a wave, it will still keep you warm.”

Finisterre beanie hat

£35 at Finisterre

Sealskinz waterproof cold-weather beanie

£24 at Sealskinz £32.95 at Outdoor Action

***

Invest in a good change robe

“Change robes are designed to keep the weather off your body while you change underneath. They’re roomy enough for you to build up layers. A good robe should have a weatherproof outer and be insulated on the inside. Longer length is ideal, so covering your lower back, bum and tops of legs. We want our core to warm so our body can warm the rest.

“This robe offers all my favourite elements as well as a lumbar warmth panel. Other elements are a zipped inner pocket and a proper weatherproof outer.”

Outdoor changing robe

£90 at Voited

For more, read the Filter’s rundown of the best thermal swimsuits and wild swimming essentials

***

Paddy Maddison is a consumer journalist, outerwear enthusiast and exercise addict. If he’s not hiking in the hills, he’s grinding up them on his bike, hurtling down them on his snowboard, or lacing up his running shoes and hitting the pavements. As a result, he gets plenty of time to put all the latest and greatest gear through the wringer for the Filter