Running base layers are essential for the colder months of the year. This additional tight-fitting layer gives you more warmth without inhibiting breathability too much. Pair them with an appropriate running jacket and you've got a great cold weather running combo.
In this guide you'll find our best tested base layers for running. The term 'base layer' is a bit of an umbrella term these days. So if you're really after running tops, you can find the best of those in our roundup of the best running t-shirts.
What to look for in a running base layer

Comfort: Crew neck, zip, short sleeve - go for what you like best. It's a totally personal preference. But everyone should look for base layers with a seamless design to avoid chafing. Stretch is important too because it allows freedom of movement.
Breathability: Technical polyester such as Coolmax is great for breathability. Lightweight merino is too, and an excellent thermoregulator, meaning it helps keep you at a comfortable temperature irrespective of the ambient temperature. Mesh panels in base layers are always a big help to breathability. You can even find these on merino base layers now.
Material: Running base layers have diversified to be made of all sorts of materials, from polyester to merino to plant based Tencel. All focus on breathability and warmth but the balance of each varies between base layers.
Odour control: Merino is naturally antibacterial and therefore does a stellar job of battling odour. Synthetic fabrics need anti-odour treatments.
Sustainability: With running base layers made from synthetic material, the use of recycled material is always best. For merino look for mulesing-free or certification such as the Responsible Wool Standard.
When wet: Cotton is a no-no. It drains body heat when wet and gets super heavy since it's so absorbent. Polyester and nylon do a much better job of remaining effective when wet. Merino wool is the best.
Thumb loops: These are a non-essential feature that simply come down to whether you like them or not. If you tend to get cold hands when running but don't want to slip on a pair of running gloves, thumb loops could be a good compromise to kepeing you warm.
The best running base layers
1. Artilect Goldhill 125 Zoned Crew
Best in Test
Description
This is a remarkable merino base layer. For those after a dependable companion for winter runs, go
Pros
- Versatile
- Like merino on steroids
- Sustainable
Cons
- Expensive
2. Madison Isoler Mesh
Best Value
Description
Those after a low-cost base layer will find it hard to go past this. This skin-tight mesh base
Pros
- Very affordable
- Very breathable
- Short sleeve available
Cons
- Only 3 size options
- No mention of sustainable materials
3. Craft Active Extreme X
Best base layer for high intensity runs
Description
If you’re a fast, hard, gritted-teeth kind of trail runner, Craft’s Active Extreme X is for you.
Pros
- Great for intense winter runs
- Contains recycled material
Cons
- Tad pricey (but worth it)
4. Zerofit Heatrub Move Baselayer
Best running base layer for winter
Description
The first thing you notice about the Zerofit Heatrub Move, is that it’s thicker than most base
Pros
- Very warm
- Very breathable
- Big size range
Cons
- No recycled material used
5. Icebreaker 125 ZoneKnit Merino Short Sleeve Crewe Thermal Top
Best short sleeve base layer
Description
Long gone are the days of wool being itchy and unsuitable for sport. The outdoor industry like to
Pros
- Highly breathable
- Naturally anti-odour
- Sustainable
Cons
- Expensive
6. Inov-8 Base Elite Long Sleeve Base Layer 3.0
Recommended
Description
Inov-8's long sleeve base layer is a versatile option that will appeal to many. It is suitable for
Pros
- Made from recycled material
- Versatile
- Short sleeve available
Cons
- You’ll want another option for summer
7. Salomon Essential Lightwarm Half Zip
Best running mid layer
Description
The Essential Lightwarm Half Zip is ideal for trail running in the cold or for warming up. Many
Pros
- Lightweight
- Highly breathable
- Warm
- Versatile
Cons
- No anti-odour treatment