For climbing and bouldering, the best underwear is a stretchy boxer brief or a longer compression short with flat seams and a waistband that stays where you put it. You want enough leg to stop thighs rubbing on high steps, enough stretch to rock over onto a foothold, and a fabric that copes with chalk, sweat and a harness pressing on your hips.
What climbing asks of your underwear
Few sports load your hips the way climbing does. A single problem can include a high step, a drop knee, a heel hook and a wide bridge between two volumes. Each of those moves pulls fabric in a different direction, and anything that bunches, rolls or digs becomes very noticeable when you are hanging off two crimps.
- Range of movement: the fabric has to stretch in every direction without the legs creeping up.
- Harness friendly: on routes, leg loops and the waist belt sit right over your waistband and leg openings.
- Sweat and chalk: indoor walls get warm, and a damp, heavy layer is uncomfortable for a long session.
- Low profile: thick side seams or bulky waistbands press into your skin under a harness.
Best cuts for bouldering vs roped climbing
Bouldering and roped climbing feel similar from the waist down, but the harness changes things. Here is how the main cuts compare.
| Cut | Bouldering | Routes with a harness |
|---|---|---|
| Long-leg compression shorts | Great for high steps and wide stances | Leg loops sit on smooth fabric, not skin |
| Boxer briefs / trunks | The all-round choice if the hem stays put | Fine, as long as the legs do not ride up under the loops |
| Briefs | Light and free, but thighs may rub | Leg openings can sit right where the loops press |
| Loose boxers | Fabric bunches on drop knees | Folds get trapped under the harness |
If you already know you prefer a longer leg, our comparison of compression shorts vs boxer briefs goes deeper into when each one makes sense.
Long-leg compression shorts for big moves
A longer, close-fitting leg is the easiest way to stop chafing on the inner thigh when you stem, bridge or rock over. It also means the harness leg loops rest on fabric instead of skin.
Our compression shorts have a 9-inch leg in 90% polyester and 10% spandex, flatlock seams, an elastic waistband and a 3D U-shaped pouch with mesh in the groin area for airflow. They come in blue, brown, navy blue, green, black and sky blue, sizes S to 2XL. Wear them on their own under loose climbing trousers or as a base under shorts.
Boxer briefs that stay put on high steps
For most climbers a good trunk is the everyday answer. The key detail is the hem: a leg that grips lightly will not roll up when you lift a knee to your chest.
- Quick Dry Modal Trunks: 91% modal and 9% spandex, a mesh U-pouch for airflow and hemmed legs designed to stop ride-ups. Colours: silver, blue, black, green and grey, sizes S to XXL.
- Ice Silk Trunks: soft, fast-drying modal with a low-rise cut, flat seams, mesh panels and a 3D contour pouch. Eight colours, sizes S to XXL. They run small, so size up.
- Cotton Boxer Brief: 95% cotton and 5% spandex with a 3D pouch and a soft waistband knit with spandex so it does not dig in. Green, black or navy blue, sizes S to XXL.
If your legs tend to escape upwards whatever you wear, these fixes for boxer briefs riding up also apply on the wall.
Fabrics: modal, cotton or synthetic?
Each fabric suits a different kind of session:
- Polyester and spandex: the most hard-wearing option and quick to dry. Best for long sessions, warm gyms and outdoor days with a harness.
- Modal blends: very soft and smooth with plenty of stretch. A good fit for indoor bouldering where comfort matters more than abrasion resistance.
- Cotton with spandex: familiar and breathable, ideal for shorter sessions or if you head to the wall straight from work.
Whatever you pick, avoid heavy waistbands and thick side seams, because they press into you under a harness belt.
Practical tips for the climbing wall
- Do a test squat: before you buy a new cut, check it in a deep squat and a high step. If the legs move, they will move on the wall too.
- Pack a spare pair: a fresh pair after a long session makes the trip home far more pleasant.
- Wash chalk out promptly: shake out chalk dust before washing and wash on a gentle cycle so the elastic keeps its grip.
- Think about the outer layer: stretchy shorts or trousers matter as much as what is underneath. Our shorts collection has lightweight options for warm gyms.
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Frequently asked questions
Can I climb in regular boxers?
You can, but loose boxers tend to bunch on drop knees and get trapped under harness leg loops. A fitted trunk or boxer brief is much more comfortable.
Are compression shorts good for bouldering?
Yes. A long, close-fitting leg prevents inner-thigh rubbing on wide moves and stays in place on high steps.
What should I wear under a climbing harness?
Choose underwear with flat seams and a slim waistband, ideally with a leg long enough that the harness loops rest on fabric rather than skin.
Which size should I choose for climbing?
Your usual size is normally right. Check each product page, because some styles, such as our Ice Silk Trunks, run small and are better one size up.
Find your climbing pair
Browse our boxer briefs for everyday sessions or the sportswear collection for longer compression styles. Every order ships in discreet packaging.
