Skip to content
Contact us
  • Men's Thermal Base Layers Men UNDER H
  • Men's Thermal Base Layers Men UNDER H
  • Men's Thermal Base Layers Men UNDER H
  • Men's Thermal Base Layers Men UNDER H
  • Men's Thermal Base Layers Men UNDER H
  • Men's Thermal Base Layers Men UNDER H

UNDER H - Men

Breathable anti-odour technical boxer shorts

29,90 €

518 reviews

Breathable

Antibacterial

quick-drying

100g

Black

Delivered from Tue 17 Nov.

Free returns within 30 days

Available in several versions

Free repairs for life

By La Réparerie, our repair service.

Complete your outfit

Who did we design it for?

For hikers and trail runners heading out regularly, from days in the mountains to multi-day treks.

How breathable is it?

The breathable fabric wicks away moisture and dries quickly, so it does not cling to your skin during exercise.

How much support?

The longer leg covers the upper thighs and moves with every step, whether walking or running. The fit is close without feeling tight.

How do they control odours?

POLYGIENE® StayFresh technology provides lasting odour control, including over several active days, without affecting the fabric’s breathability.

Ideal for

Lifestyle

Travel

Hiking

Trail running

Boxer shorts you can forget you are wearing

On a hike or out on the trail, you only notice a base layer when it gets in the way. Thighs rubbing, moisture against the skin, odours building up over the days.

These boxer shorts have a close fit and longer legs that stay in place. The breathable fabric wicks away moisture, the wide elastic waistband stays put, and an anti-odour treatment limits odours from one outing to the next.

Wear them directly against the skin, under your hiking, trail or travel clothing.

Because a good base layer is one you do not have to adjust halfway through.

Key features

Flat seams

- Flat seams help reduce rubbing where they meet your trousers.

Wide elastic waistband

- Stable hold without waist compression, even when bending.

Ergonomic crotch cut

- Total freedom of movement on steep climbs.

Breathable mesh at the back

- A mesh panel below the waistband lets air circulate around the lower back.

POLYGIENE® StayFresh technology

Contrôle durable des odeurs pour un confort prolongé pendant l’activité.

  • Technologie anti-odeurs : limite le développement des bactéries responsables des mauvaises odeurs.
  • Entretien réduit : permet d’espacer les lavages et de prolonger l’usage du vêtement.
  • Confort préservé : traitement intégré qui n’altère ni la respirabilité ni le toucher du textile.

Développée par Polygiene®, spécialiste des technologies de contrôle des odeurs, la technologie POLYGIENE® STAYFRESH™ assure durabilité et efficacité dans le temps.

Details

Specifications

Weight

100g

Brand

Cimalp

Fabrics

Main fabric: 85% Polyamide, 15% elastane; ventilation mesh: 92% Polyester, 8% elastane

Size type

  • Men's Bottoms

Traceability

Product sheet on environmental qualities and characteristics
Manufacturing: China
Weaving/Knitting: China
Dyeing/Printing: China
Releases plastic microfibres into the environment when washed

Complementary products

Hiking accessories DRY BAG 3L
  • Hiking accessories DRY BAG 3L
Men's trail running T-shirts BAUGES 4 H
  • Men's trail running T-shirts BAUGES 4 H

+4

Merino wool Socks AIR
  • Merino wool Socks AIR
Men's trail shorts and trousers AOSTE 3 H
  • Men's trail shorts and trousers AOSTE 3 H

+1

Reviews

4.9
Based on 518 reviews
5
93%
4
5%
3
0%
2
0%
1
0%
Customers recommend the usual size
Comfort
Breathability

In summary This content is written by AI

Customers especially appreciate its comfort, flexibility and pleasant fabric, with some describing it as a second skin. Many highlight the absence of chafing, the very flat seams, its featherlight feel and the fact that it does not build up heat. It stays in place, wicks away moisture and remains breathable, whether hiking or running anything from short distances to ultra trails. Several customers also praise its durability, and some have already ordered more. A particularly good choice for outdoor activities.

Arnaud C.
Verified customer
Height 180cm Usually wears L Ordered size M Ordered color Noir / rouge Usage Randonnée
Translated review
22/10/2026

It fits exactly how I like it. I bought a Jorasse jacket a year ago, truly extraordinary. At first, I had a size M, way too small, so the L was perfect. Only a minor downside: the small attachment at the collar of the Jorasse is too fragile for hanging on a coat rack. Such a shame, it's so practical. Otherwise, this jacket is extraordinary. I'm going to buy it again soon without the hood in size L. Thank you for your dedication.

Arnaud C.
Wolfgang L.
Verified customer
Usually wears L Ordered size L Ordered color Noir Usage Trail running, Randonnée, Alpinisme, Ski de fond, Raquettes
Translated review
30/10/2026

Wonderfully flexible, no heat buildup, barely noticeable to wear. The seams are super flat, nothing chafes or bothers you. Perfect, I've already ordered 2 more.

Peter B.
Verified customer
Ordered size L Ordered color Noir / rouge Usage Trail running
18/09/2026

Game changer. Will definetly purchase another pair. Or, alternatively, you can ship me a free pair 🤷🤣

Jean-François.M
Verified customer
Ordered size S Ordered color Noir / Rouge
Translated review
23/01/2026

At 1.83m tall, size L fits me perfectly. These boxer shorts are very comfortable and breathable; I experienced no irritation after 4 hours of intense downhill skiing. I highly recommend this product. I will definitely be ordering more.

Bruno.B
Verified customer
Ordered size S Ordered color Noir / Rouge
Translated review
03/01/2026

Size S is perfect for me at 1.70m and 60kg. I already had iomaFresh briefs for hiking in the summer. I tested the boxer shorts for skiing and hiking in the snow in December. Very comfortable to wear and keeps you warm. I ordered more to complete my collection :)!

Explore the category Men's Thermal Base Layers

Men's Thermal Base Layers WOOL TOP 240 H
  • Men's Thermal Base Layers WOOL TOP 240 H
Men's Thermal Base Layers WOOL PANT 240 H
  • Men's Thermal Base Layers WOOL PANT 240 H
Men's Thermal Base Layers WOOL TOP 200 H
  • Men's Thermal Base Layers WOOL TOP 200 H
Men's Thermal Base Layers STRATEGIC TOP 5 H
  • Men's Thermal Base Layers STRATEGIC TOP 5 H
Men's Thermal Base Layers X-WARM ZIP 5 H
  • Men's Thermal Base Layers X-WARM ZIP 5 H
Men's Thermal Base Layers WOOL ZIP 240 H
  • Men's Thermal Base Layers WOOL ZIP 240 H
Men's Thermal Base Layers WOOL PANT 200 H
  • Men's Thermal Base Layers WOOL PANT 200 H
Men's Thermal Base Layers STRATEGIC PANT 3 H
  • Men's Thermal Base Layers STRATEGIC PANT 3 H

F.A.Q

We answer your questions

Need help?

Our team of experts, based in Valence in the Drôme, will get back to you quickly by email, from product advice to order tracking.Based in the French Alps, our specialist team provides prompt email support for product guidance, order tracking, and any other inquiries.

FAQ

Frequently asked questions

Choose your usual size and check it against the size guide on the product page. If you are between sizes, choose the smaller one for a more secure fit.

No: for hygiene reasons, UNDER and JULIOZ underwear cannot be returned. Check your size against the size guide before ordering.

No: the panels are joined by seams visible in the photos. The longer leg and ergonomic crotch panel help reduce rubbing.

The POLYGIENE® treatment limits odours and lets you wash them less often, but does not remove the need to wash them. How many days you can wear them depends on your activity level and the heat.

Fitted boxer shorts move with you, while loose-fitting underwear can shift around. These have a close, second-skin fit and are worn directly against the skin.

Wash them at a maximum of 30 °C without fabric softener: it blocks the fabric’s micropores and slows the release of sweat. They air dry very quickly; avoid tumble drying.

All orders placed by midnight are prepared the next day. In France, orders placed before 1 pm (excluding weekends) with Chronopost 24h are dispatched the same day. Delivery then depends on the carrier and takes 1 to 4 days in France. Delivery times for Europe and the rest of the world vary by destination.

Are you in the right place?

Select your shipping country