What to wear for trail running: layers for every season
What to wear for trail running in any weather: wicking tops, shorts or tights, windproofs and waterproofs, socks, and which of our running kit suits each.
For most trail runs you need a wicking top, shorts or tights, thin running socks and trail shoes, plus a windproof or waterproof jacket you can carry. Everything next to your skin should move sweat away and dry fast, so you don't get cold when you slow down on a climb or stop at a gate.
A common rule of thumb is to dress as if it's about 10°C warmer than it is. You'll warm up within the first mile, and it's easier to carry a light layer than to run overheated in a heavy one.
In this guide
- What to wear for a trail run
- Tops and underwear next to your skin
- Shorts, 3/4 tights or full tights
- Windproof or waterproof jackets for running
- Staying warm on cold runs
- Socks and shoes for the trail
- Dressing for the season
- Our trail running kit and what each is for
What to wear for a trail run
Trail running is layering on a small scale. You can't carry much, and you go from hard climbing to fast descents and back again, so each piece needs to work across a wide range.
- Always: a wicking tee or long sleeve top, shorts or tights, wicking underwear, running socks and trail shoes.
- In your pocket or vest: a windproof or waterproof jacket, and on cooler days a hat and light gloves.
- On cold days: a thin fleece or insulated layer for stops, or to wear on easy sections.
- On races and remote runs: check the kit list. Many fell races follow the Fell Runners Association's requirements, which ask for full waterproof body cover with taped seams and a hood, plus a hat and gloves.
The same principles apply to every layer, and our layering guide covers them in more depth.
Tops and underwear next to your skin
The layer next to your skin does the most work. When you're running hard, you're sweating for most of the time you're out, and a top that holds that sweat turns cold and heavy as soon as the pace drops. Cotton is the worst for this, so leave it at home, underwear included.
Synthetic tops get rid of sweat fastest, which is why most runners wear them most of the year. Merino evens out your temperature and doesn't smell, so it suits cold days, long ultras and multi-day runs where you're wearing the same top for hours or days. Our merino or synthetic base layer guide explains how each fabric works, and base layers for trail running goes through our running tops.
Wear underwear made for running too. A wicking, close-fitting pair with flat seams stops chafing on long runs, which matters more the longer you're out.
Shorts, 3/4 tights or full tights
Shorts give you the most freedom and stay coolest, so they're the default from spring to autumn. Look for a light outer with a mesh liner, a split hem for a long stride, and a pocket that holds keys and a gel without bouncing.
3/4 tights sit between the two. They keep your knees and thighs warmer on cool mornings, stop thigh rub on long runs and still leave your lower legs free.
Full tights are for cold and windy days and winter runs. A close fit with four-way stretch keeps your muscles warm and wind off your skin without slowing you down. Our trail running tights guide covers the choice in more detail.
Windproof or waterproof jackets for running
Most of the time a windproof is the jacket you want. A thin windproof stops wind chill, which is what makes you cold on a ridge or a fast descent, and it breathes far better than a waterproof, so you can run in it without overheating. It packs small enough to live in a pocket.
A waterproof is for rain that won't stop, and for any run where you'd be in trouble if you got soaked and slowed down: remote trails, high ground, winter. For running, it needs to be very light, very breathable and quick to pack away, with a hood that stays put in wind. Breathability matters more than for walking, because you're producing far more heat and sweat.
A jacket with a thin membrane sits in between: windproof and showerproof, with more protection than a plain windproof but less than a full waterproof. See waterproofs and windproofs for runners for our running jackets, and how to choose a waterproof jacket for how ratings and breathability work.
Staying warm on cold runs
On cold days, add warmth in thin layers rather than one thick one. A long sleeve top with a light micro fleece over it lets you vent or take a layer off as you warm up, and a fleece breathes well enough to run in.
Carry something warmer for stops on long winter runs and in the mountains: an insulated jacket or gilet goes on the moment you stop, so you don't lose heat while you eat, navigate or wait for someone. Our guides to fleeces for trail running and insulated clothing for trail runners go into more detail.
Hands and head lose heat fastest when it's cold and windy. A thin hat and light gloves weigh almost nothing, and a glove with a pull-over windproof mitt gives you two levels of warmth in one.
Socks and shoes for the trail
Socks for running are thin and fit close, so they don't bunch or rub. Look for wicking fabric, mesh panels for breathability on warm runs and light cushioning where your foot strikes. Merino blends stay warmer and smell less on long or cold runs; all-synthetic socks dry fastest. Ankle length suits most runs, and a longer sock helps on overgrown trails. Our running socks guide compares them.
Trail shoes need deep lugs for grip in mud and on loose ground, a snug heel and enough room at the toes for your feet to swell over a long run. Most trail runners find they get wet feet anyway, so a shoe that drains and dries quickly is often more comfortable than a waterproof one.
Dressing for the season
Summer. Shorts, a light tee, a cap and thin socks. Carry a windproof on hill runs, because it's often much cooler and windier on the tops than at the car park.
Spring and autumn. The most changeable seasons. A long sleeve top or tee with 3/4 tights, a windproof you can take on and off, and a hat and gloves in your pocket for early starts. See layering for spring trail and alpine running.
Winter. Full tights, a long sleeve top, a light fleece on the coldest days, a waterproof and a hat and gloves. Carry a warm layer for stops, and allow for shorter daylight. See dressing for autumn and winter trail running.
Our trail running kit and what each is for
Koulin Trail tops: when you're working hard and sweating a lot. Recycled polyester with mesh panels under the arms and across the back, and Polygiene against odour. The Koulin Trail Tee (women's) for warm runs, the Long Sleeve (women's) for cooler ones.
Koulin Trail Shorts: when it's warm and you want to move freely. A light stretch outer with a breathable mesh liner and a split hem. Men's and women's.
Koulin Trail 3/4 Tights: when you want a little more cover on cool or long runs. Close-fitting and breathable, ending mid-calf. Men's and women's.
Koulin Trail Tights: when it's cold or windy. Full length with four-way stretch, and thigh pockets for essentials. Men's and women's.
FKT Boxers: when you want underwear that won't rub on long days. Moisture-wicking, fast-drying and stretchy. Men's and women's.
Arro: when the wind is the problem, not the rain. A 100% windproof, lightweight nylon windshirt with a soft, quiet fabric. Men's and women's.
Cirrus: when you want wind protection that also keeps off a passing shower. Windproof with a thin waterproof membrane, packing into its own pocket. It's showerproof rather than a full waterproof. Men's and women's.
Gravitas: when you need a real waterproof that's light enough to run in. A 3-layer jacket rated 20K waterproof and 20K breathable, at about 200g, with a hood that stays put in high winds. Men's and women's.
Kelpie: when you need a little warmth that still breathes. A light micro fleece that dries fast and layers under a shell. Men's and women's.
Socks: Scape for warm runs, Repeat for cold or long ones. Scape is ankle length with zoned mesh panels and comes in a pack of two. Repeat blends merino with Coolmax and Thermolite fibres for warmth and comfort.
Hands and head. The Specta Pullover Glove is a close-fitting glove with a windproof mitt that pulls over your fingers when the weather turns. The Koulin Cap keeps sweat out of your eyes and the sun off your head, and folds into a pocket.
See all our running kit.
Further Reading
- Baselayers for Trail Running
- Best Fleeces for Trail Running
- Trail Running Waterproofs and Windproofs
- Find Your Perfect Trail Running Tights
- Best Socks for Trail Running
- Dressing for Autumn and Winter Trail Running
- How to Prepare for the Winter Running Season
- How to Winterise Your Running Kit
- Layering for Spring Trail and Alpine Running
- Arro Trail Running Windshell
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