Best running base layers to keep you comfortable in 2025

The best base layers are versatile and affordable (and we’d say pretty darn mandatory) purchases to be worn on their own when it’s milder or under the best running jackets in the cold.

Base layers need to perform the dual act of keeping you warm on the run but also providing plenty of breathability and moisture wicking to stop an excessive build up of sweat.

To achieve this, the best running base layers fit close to the skin and provide ways to cool you down or allow moisture to escape, such as neck zips or mesh panels.

Of course, they also need to be comfortable, so bonded or flatlock seams are preferred. See some of our favourites below.

Best base layers for running in 2025

1. Falke Long Sleeve Top

Price	£67 / $84
Features	Recycled material, 2-way construction,
Sizing	S – 2XL

We have to admit it took us a while to find Falke’s sport range on their website, as we became lost in a world of knee-high socks and men’s knitwear.

Yet judging by the Long Sleeve seen here, the German brand’s lack of a sport-specific focus hasn’t impacted on the athletic quality.

Once on, the 69% polyamide/26% polyester/5% spandex composition was close-fitting but not restrictive and didn’t ride up, offering compression for those of you convinced of the upper-body benefits.

The temperature regulation is also hugely efficient, keeping us warm and free from cold sweat patches throughout.

It’s also stylish enough to be worn as a single layer come the warmer months and, if that price sounds high, the quality construction should last you multiple off-seasons.

2. Montane Dart Lite Long Sleeve T-Shirt

Price	$65 / £50
Weight	4.2oz / 120g
Features	Recycled polyester, odour control, flatlock seams
Sizing	XS – 3XL

Montane bill the Dart Lite Long Sleeve T-Shirt as a base layer, but I’ve happily been wearing it as a standalone long-sleeved running top in the UK autumn. I’ve regularly relished its lightness, (a 120g for a men’s medium). 

Internal comfort is excellent. The flatlock seams have remained irritation-free, while the 100% recycled polyester is soft on the skin. The crew neck is comfortable, while the fit felt true to the sizing chart.

Like the Keela Trail Pro and Alpkit Laika, this boasts a Polygiene permanent odour control in a bid to make you wash it less often. Ventilation is impressive, nonetheless, and the Dart Lite has proven both quick-to-dry and breathable when worn under a jacket.

The sleeves roll up and sizes range from XS to 3XL, with a range of colourways in men’s and women’s versions.

3. Montane Dart Thermo Zip

Price	$75 / £60
Weight	4.2oz / 120g
Features	Recycled nylon, brushed interior, quarter zip
Sizing	S – 3XL

The Dart Thermo Zip Neck is designed to act as a winter base layer or standalone layer between seasons. It’s made of the brand’s Apex Thermo Eco recycled nylon (88%) and spandex (12%), delivering eco credentials and durability in equal measure.

But it’s the level of comfort on offer that really makes you sit up and take notice. The brushed interior feels luxuriously soft against the skin, while the fit was spot on for this tester, sitting close against the skin without being too snug.

The length of both the arms and the torso are also generous, while the seams are flatlocked, limiting any chance of irritation.

It’s incredibly warm, too, keeping us toasty when running in single-digit temperatures. When paired with an outer layer, it’s also one of the best base layers for running in sub-zero conditions.

Both the close fit of the arms and the neck collar help with this, stopping any cold air sneaking. If you do find yourself overheating, though, the 1/4 zip is handy for ventilation and temperature regulation.

The Dart Thermo’s ability to wick moisture away is also worth mentioning. While the garment does pick up moisture, it doesn’t take on as much as some others we’ve tested in the past.

4. Compressport Performance L/S

Price	$80 / £70
Weight	4.9oz / 138g
Features	Microfibre, ventilation, thermoregulating
Sizing	S – 2XL

This long-sleeved, thermo- regulating performance top has integrated ventilation with some mesh panels as well as a woven fabric which felt light and cool against the skin.

It’s made from 52% Polyamide 44% Polyester 4% Elastane and came in at 138g for my size large. Again sizing is limited here, with XS-L available for women and S-XXL for men.

On mild autumn runs I really liked how this top felt against the skin and it was among the cooler and most breathable on test, plus the flexible fabric made the sleeves easy to roll up when I got a bit warm.

On cooler days it worked well under a short-sleeved tee or light jacket. No pockets are included and thumb loops on the long sleeves would have been welcome.

5. Gore Essential Base Layer Long

Price	£54.99 / $70
Weight	3.2oz / 91g
Features	Flatlock seams, moisture-wicking
Sizing	XS – XL

The Essential Long may be Gore’s cheapest base layer, yet it still oozes high quality, with the 88% polypropylene material feeling so soft on the skin that it also entered our casual clothing range as well.

Once out on the trails in cold December conditions, the microfibre composition was up there with Tenn, Dhb and Falke as the quickest-drying on test, and the base layer didn’t produce any nasty cold sweat patches during our runs.

Again, the top was close-fitting but didn’t restrict our arm movement. The Essential, however, was the only top on test where we felt chilly well into the run’s duration, especially on exposed stretches and tackling winds on hill tops (all the base layers were tested in similar conditions and dealt well with the cold), so we’d definitely opt for something more insulated in the depths of the winter.

6. EDZ Merino Long Sleeve Base Layer

Price	£54.99 / $70
Weight	7oz / 200g
Features	100% merino wool, anti-microbial, moisture-wicking
Sizing	S – 3XL

The first thing to note here is that this EDZ Merino Long Sleeve Base Layer is pretty basic in its design. There’s no pocket, thumb loops or reflective details, nor a neck zip.

That said, it’s made from 100% merino wool, which is known for its ability to regulate temperature. Other benefits of this fabric are that it’s naturally anti-microbial and stays warm when wet.

The garment fits true to size, too, but doesn’t sit especially close to the body. It’s comfortable on the whole, in part thanks to its flatlock seams, but doesn’t quite reach the same levels as the Montane garment.

It’s also not quite as accomplished at wicking moisture and drying off, but that’s a feature of merino wool.

In terms of the warmth that is on offer, it’ll be enough for most runners in single-digit temperatures that are layering it with another thin garment.

7. Soar Tempo

Price	$200 / £155
Weight	4.8oz / 136g
Features	Full-length zipper, rear zip pocket, bonded construction
Sizing	XS – XL

At just 136g for my size XL (I’m a UK14, but Soar comes up small and this is the largest size – our model here could size down) this unusual base layer is amazingly light for its features.

The 3D textured weave fabric has a slight stretch and is brilliantly breathable – the Tempo is designed to be worn over a light base layer or alone next to the skin and I found it comfortable either way, with the full-length zip adding to the versatility.

The seams are bonded and comfortable and though there is no zip garage, I didn’t notice any irritation. At the back there’s a decent pocket for keys/gels which is welcome.

The price tag is high, yes, but this is a beautifully-made and functional top, and one of the best base layers for running.

8. Adidas Techfit Long Sleeve top

Price	$35 / £54.99
Features	Recycled polyester, UPF protection, compressive,
Sizing	XS – 3XL

Whether it’s down to the 84% polyester/16% elastane composition or any placebo effect of wearing white, straight out of the box the Techfit Base from Adidas oozes lightness.

This litheness continues onto the run with a snug yet unrestrictive feel when running, although we didn’t feel any of the purported upper-body compression benefits touted by the German heavyweights.

Adidas claims its Climalite fabric ‘sweeps sweat away from your skin’, and possibly it does this too well, as the Techfit Base remained noticeably damper and clingier once out on the trails than the Gore and Falke offerings, especially on the back region.

The perforated panels on the shoulders are successful at providing more breathability (these would’ve been a welcome addition on the back to fight the sweat patches), and the seams remained chafe-free throughout.

Features to look out for in a running base layer

Moisture-wicking fabric
A good base layer should efficiently pull sweat away from your skin to keep you dry and comfortable. This helps regulate your body temperature and prevents chafing during long runs.

Breathability
Look for materials with excellent airflow to allow heat and moisture to escape. Breathable fabrics help you stay cool and reduce the risk of overheating, especially during intense workouts.

Fit and compression
A snug but not restrictive fit enhances movement and can provide light muscle support. Compression features may also improve circulation and reduce muscle fatigue.

Seamless or flatlock Seams
Minimising or eliminating bulky seams prevents skin irritation and chafing. Flatlock seams lie flat against the skin, making them ideal for high-repetition activities like running.

Thermal regulation
For cold-weather runs, base layers with thermal properties help retain body heat without bulk. Some fabrics offer temperature-adaptive features to keep you warm or cool as needed.

Odor resistance
Anti-microbial treatments or natural odor-resistant materials like merino wool keep the base layer fresher for longer. This is especially important for multi-day use or high-sweat sessions.