Our pick for long day walks
Walk all day.
No thigh rub.
Flissie women's bamboo boxer shorts are buttery soft and breathable, with a 6 inch leg that stays put mile after mile, so your thighs glide instead of rub. Every size from UK 8 to 30, at one price.
4.7 out of 5 from 336 reviews
Choose my pair£13.50 a pair, or £11.50 in a 10 pack. Free UK delivery. 60 Day Wear Test.
This compares five kinds of hiking underwear for women, from merino briefs to long-leg boxer shorts for women, on fabric, leg length, dry speed and price. Specifications checked on each brand's own site in August 2026, with prices, ranges and policies rechecked on 7 October 2026.
At a glance
Best hiking underwear for women: the short version
For a long day walk where thighs rub, you need a long leg, and no merino brand makes one. Every merino option here is a brief, a bikini or a hipster, all of which stop well short of where thighs actually touch.
For a multi-day trek where you wash as you go, merino dries fastest. Icebreaker and Smartwool are the brands to look at.
- A long day walk when thighs rub, UK 8 to 30: Flissie women's bamboo boxer shorts (we make them): buttery soft bamboo viscose with a 6 inch leg that stays put, mile after mile. £13.50 a pair (£11.50 in a 10 pack).
- Multi-day trek, washing as you go: Icebreaker's Merino 150 Siren Hipkini, which had the fastest dry time of every pair in CleverHiker's side-by-side test. £35.99.
- Merino with a softer feel: Smartwool's Everyday Merino Bikini, 53% merino and 47% lyocell, close behind on dry time. £31.99.
- Fast hiking, hill running and heavy sweat: Runderwear's Women's Running Long Boxer, recycled polyamide with an 8 inch inseam. £23.
- Bamboo viscose from UK 6: Boody's 6 inch Seamfree Undershorts, XS to 4XL (UK 6 to 22). £18.
Our pick for a long day walk where thighs rub: Flissie women's bamboo boxer shorts (we make them), with a buttery soft 6 inch leg that covers the top of the inner thigh and stays put, in UK 8 to 30 at one price. They are £13.50 a pair (£11.50 in a 10 pack), with a 60 day guarantee, full refund, worn or not.
Updated 10 November 2026. Prices are for one pair, checked on each brand's own UK site on 7 October 2026. Flissie's price updated on 11 November 2026.
Rated 4.7 out of 5 from 336 reviews (Judge.me, 10 November 2026)
"Perfect anti-chafe shorts! Really soft, light weight boxer shorts, they come to a good length to prevent chafe and are a lot cooler than my sports shorts"
Verified buyer, United Kingdom, April 2026
"These boxers are brilliant as the leg doesn't ride up and nothing digs in."
Val, United Kingdom, verified review, December 2025
"I have now bought this style pants from 4 suppliers and these are by far the best. Extraordinarily comfortable, they don't ride up and fit so well...love them."
Verified buyer, United Kingdom, April 2026
"They never rolled up under my trousers and the waist band was unnoticeable"
P.O., United Kingdom, review, January 2023
"The material is very lightweight and breathable, and the sizing/fit is perfect. Love the colours!"
Amalie, United Kingdom, verified buyer, August 2026
"Fabulous once I got the right size!"
Marian, United Kingdom, verified buyer, May 2026
Some reviewers earned a reward towards a future purchase.
Try them for 60 days
The 60 Day Wear Test
Wear them for 60 days. Under dresses, on long walks, through the wash. If they ride up, rub or roll, send them back for a full refund, worn or not.
- 10 pairs of Flissie women's bamboo boxer shorts in your colours and sizes (£135 at the single price)
- A free 30 day tub of our perimenopause supplement (worth £29)
- Free UK delivery
- Free size swap on your whole first order, as long as you try one pair and send the rest back unopened
- The 60 Day Wear Test: a full refund, worn or not
£11.50 a pair in a 10 pack £13.50
1 pair £13.504 pairs £546 pairs £7510 pairs £115
Start my Wear Test60 day guarantee from purchase: full refund, worn or not (return postage at your cost). We don't know how long we can hold these prices.
Why you can trust this guide
★★★★★ 4.7 out of 5 from 336 reviews of Flissie women's bamboo boxer shorts, and about 2,500 customers since 2021.
- Who wrote it: Phillippa and Matthew, the founders of Flissie. We have designed and sold women's boxer shorts from Derbyshire since 2021.
- Why Flissie is here: we make Flissie women's bamboo boxer shorts, built for long days on your feet, with a 6 inch leg that stays put in every size from UK 8 to 30.
- No paid placements: no brand paid to be included.
- How we compared: fabric, leg length, dry speed, returns and price, from each brand's own UK site, with prices and policies rechecked on 7 October 2026. Dry speed comes from CleverHiker's side-by-side test, not ours.
"Ridiculously comfortable and easy to wear" Tricia, United Kingdom, verified buyer, April 2026 (reviewer earned a reward for a future purchase)
The five options, compared
| Brand | Fabric | Longest leg | Dry speed | Odour resistance | Returns once worn | Price, one pair |
|---|---|---|---|---|---|---|
| Icebreaker | Merino wool | Hipkini, short | Fastest | Excellent, natural | Standard policy | £35.99 (Siren Hipkini) |
| Smartwool | Merino and lyocell | Bikini, short | Very fast | Excellent | Standard policy | £31.99 (Everyday Merino Bikini) |
| Runderwear | 92% recycled polyamide, 8% elastane | 8 inch long boxer | Very fast | Poorer, synthetic | None once tried on, but a 90 day chafe-free guarantee | £23 |
| Flissie (ours) | 95% bamboo viscose, 5% elastane | 6 or 9 inch | Moderate | Not claimed | 60 days, free swap on whole first order | £13.50, or £11.50 a pair in a 10 pack |
| Boody | 79% viscose from bamboo, 15% nylon, 6% elastane | 6 inch undershort | Moderate | Not claimed | Comfort Guarantee on your first single pair | £18 (6 inch undershort) |
On a phone, swipe the table sideways to see every column.
1. Icebreaker, for multi-day trekking
Best for: multi-day treks where you wash as you go
| Price | £35.99 for the Merino 150 Siren Hipkini (7 October 2026). |
|---|---|
| What you get | A hipster bikini in 83% merino wool, 12% nylon and 5% elastane, XS to XL. |
| Pros | The fastest dry time of every pair in CleverHiker's side-by-side test. 4.8 out of 5 from 778 reviews on Icebreaker's UK site. |
| Cons | Coverage: Icebreaker's women's range is briefs, hipsters and bikinis, and if your thighs rub, none of them reach far enough down to stop it. The most expensive pair here. Cold gentle wash and line dry, with no fabric softener. |
Merino wool, and the Merino 150 Siren Hipkini recorded the fastest dry time in CleverHiker's side-by-side testing. Merino's real advantage on a multi-day trip is odour resistance: you can wear a pair for several days in a way you cannot with anything else here.
2. Smartwool, the same trade with a softer hand
Best for: merino with a softer feel, from its lyocell blend
| Price | £31.99 for the Everyday Merino Bikini (7 October 2026). |
|---|---|
| What you get | A bikini brief in 53% merino wool and 47% lyocell, XS to XL. |
| Pros | Close behind Icebreaker on dry time in CleverHiker's test. Smartwool says it can go in a warm wash and a low tumble dry. |
| Cons | Bikini cut, so no thigh coverage. Priced at the higher end. Smartwool's own fit note says it runs small. |
Merino blended with lyocell, which adds softness and helps with odour resistance. CleverHiker put the Everyday Bikini among the fastest drying they tested.
3. Runderwear, the technical long leg
Best for: fast hiking, hill running and heavy sweat, with an 8 inch leg
| Price | £23 (7 October 2026). |
|---|---|
| What you get | An 8 inch long boxer in 92% recycled polyamide and 8% recycled elastane, with 360° seamless construction and silicone grippers around the leg hems, S to XL. |
| Pros | The technically strongest long leg here for fast hiking and heavy sweat, with a 90 day chafe-free guarantee: Runderwear refunds you if a pair makes you chafe. 4.8 out of 5 from 197 reviews. |
| Cons | Outside that guarantee, Runderwear's returns policy says it cannot accept returns on any underwear that has been tried on. Synthetics hold on to smell more than merino over several days. Sizes stop at XL. |
92% recycled polyamide with 8% elastane, 360 degree seamless construction, flatlock edging, and silicone grippers around the leg hems to stop them travelling. The women's long boxer has an 8 inch inseam, which is long enough to reach where thighs touch.
If you walk fast, sweat hard or run the descents, this is the technically strongest long-leg option here.
4. Flissie, a long leg in bamboo viscose
Best for: a long day walk in warm weather when thighs rub, with a 6 inch leg, in UK 8 to 30
| Price | £13.50 a pair, or £12.50 a pair in a 6 pack and £11.50 a pair in a 10 pack. The same price in every size. Free UK delivery. |
|---|---|
| What you get | A boxer short with a 6 inch leg in all 8 colours, or a 9 inch leg in black and pine green. 95% Tanboocel bamboo viscose and 5% elastane, dyed to OEKO-TEX Standard 100. UK 8 to 30. |
| Pros | Buttery soft, breathable bamboo viscose. The 6 inch leg covers the top of the inner thigh, where most rubbing starts, and stays put mile after mile. Feels cooler than a synthetic on a warm climb. No side seams. |
| Good to know | Made for day walks: on a multi-day trip where you wash as you go, merino dries faster. A cool wash and an air dry keep them buttery soft. |
| Reviews | 4.7 out of 5 from 336 reviews (Judge.me, 10 November 2026). |
| Guarantee | 60 days from purchase: full refund, worn or not (return postage is at your cost). Free size swap on your whole first order. |
Shown in Sage green, 6 inch leg
Also in black, pine green, taupe white and chocolate brown. The 9 inch leg comes in black and pine green. Pictured: Flissie women's bamboo boxer shorts (we make them).
See the 6 inch legWrong size? We swap your whole first order free, as long as you try one pair and send the rest back unopened.
95% Tanboocel bamboo viscose with 5% elastane, in a 6 or 9 inch leg, UK 8 to 30 at one price, dyed to OEKO-TEX Standard 100.
Bamboo viscose is buttery soft, breathes well and moves moisture rather than holding it, so it feels cooler than a synthetic on a warm climb. For a multi-day trip where you are washing in a stream, merino dries faster.
For a long day out, a coast path, a hill walk or 20,000 steps in a city, a long leg matters most if you chafe, because it puts a smooth layer between your thighs: the 6 inch covers the top of the inner thigh, where most rubbing starts, and the 9 inch reaches just above the knee.
Today I've been on an 11 mile hike in the Peak District and I didn't have to fuss with them once. They never rolled up under my trousers and the waistband was unnoticeable.
P.O., UK, verified review
I use them for hiking in particular, they are great for sports activities and general wear too.
Gemma, UK, verified review
5. Boody, the seamfree bamboo option
Best for: seamfree bamboo viscose with a 6 inch leg, in UK 6 to 22
| Price | £18 a pair (7 October 2026). |
|---|---|
| What you get | The 6 inch Seamfree Undershort in 79% viscose from bamboo, 15% nylon and 6% elastane, knitted with no side seams, XS to 4XL (UK 6 to 22). |
| Pros | Bamboo viscose with a leg that reaches where thighs touch, from a UK 6. 4.5 out of 5 from 2,576 reviews. |
| Cons | Sizes stop at UK 22, and Boody's own review summary notes that some wearers find they roll slightly. Its Comfort Guarantee covers your first single pair, for comfort only. |
Bamboo viscose, seamfree rather than flat-seamed, OEKO-TEX certified, B Corp, and sizes up to 4XL. A Comfort Guarantee on your first single pair.
Its long-leg option is the 6 inch Seamfree Undershort. At 6 inches it reaches where thighs touch, which makes it the closest thing here to ours. See our Boody underwear review for the full comparison.
What actually matters on a long day
Leg length, if your thighs touch. This is not a small factor, it is the difference between finishing comfortably and limping the last two miles. Anything stopping between 2 and 4 inches down the thigh does not reach.
Dry speed, if you are out for more than a day. On a single day walk it barely matters. On a multi-day trip where you rinse a pair each night, it is the whole game, and merino wins.
Odour resistance, for the same reason. Merino outperforms everything else here.
Seams and waistband. A pack hipbelt sits exactly where most waistbands sit. A wide flat band is better than narrow elastic under a loaded belt, and flat or bonded seams beat overlocked ones.
What does not matter as much as brands suggest: antibacterial claims. REI's guide to choosing hiking underwear is worth reading here: it says the added coverage of boxer briefs can often help reduce inner-thigh chafing, and that underwear which is too loose can bunch up and rub. That is a fit and sizing problem, not a fabric one.
Cotton, and why every hiking guide tells you not to
Cotton absorbs sweat and holds onto it. On a hill in changeable weather that is uncomfortable and, in cold conditions, a real problem, because wet fabric against skin pulls heat away from you.
The old advice that cotton kills is overstated for a summer stroll. For anything remote, long or cold, it is sound.
Sizing, which is where most people go wrong
Underwear that is too small is the most common cause of bunching and riding up on a walk, whichever brand you buy. A tighter leg has to stretch further and grips less evenly.
If you are between sizes, go up. If you are choosing between two lengths, the 6 inch is where most people start.
Being a size 16-18, horse riding 5/6 days a week, walking more than 18,000 steps a day. Soft, super comfortable, stretchy, breathable and ZERO CHAFFING. Just ordered 5 more.
A.R., UK, verified review
So what should you actually buy?
| Your trip | Buy |
|---|---|
| Multi-day trek, washing as you go | Merino. Icebreaker or Smartwool |
| Long day walk, thighs rub | A long leg. Flissie at 6 or 9 inch, Runderwear at 8 inch, or Boody's 6 inch undershort |
| Fast hiking, hill running, heavy sweat | Runderwear. Technical synthetic dries fastest |
| Warm weather day walking | Bamboo viscose. Cooler against the skin than synthetic |
| Cold or remote | Merino, and definitely not cotton |
| Tight budget | Flissie (ours, £13.50 a pair) or Boody, or any non-cotton pair you already own |
If you are only buying one pair and you chafe, buy a leg long enough to reach where your thighs touch. Fibre is the second question.
See ours here. 60 day comfort guarantee, free swap on your whole first order, free UK delivery.
How many pairs?
-
1 pair
To try your size £13.50 -
4 pairs
A rotation £54
£13.50 a pair -
6 pairs
The working week, plus a spare £75
£12.50 a pair -
10 pairs
Every day between washes, with a free 30 day tub of our perimenopause supplement (worth £29). Ten singly would be 10 × £13.50 = £135, so the pack is £20 less. £115
£11.50 a pair
Free UK delivery. 60 day guarantee. Free size swap on your whole first order, as long as you try one pair and send the rest back unopened.
Hiking underwear: your questions answered
What is the best underwear for hiking?
For a long day walk where thighs rub, a long leg, because no merino brand makes one: our pick is the 6 inch leg of Flissie women's bamboo boxer shorts (we make them), or Runderwear's 8 inch long boxer for fast hiking. For multi-day trekking, merino wool from Icebreaker or Smartwool dries fastest and resists odour naturally.
Is merino wool underwear worth it for hiking?
For multi-day trips, yes. It dries quickly and you can wear a pair for several days without it smelling, which matters when you are carrying everything. For a single day walk the advantage is much smaller and the price is much higher.
Can you wear cotton underwear hiking?
For a short summer walk, it is fine. For anything long, cold or remote, no. Cotton absorbs sweat and holds it, which is uncomfortable at best and pulls heat away from you in cold conditions.
What underwear stops chafing when walking?
A leg long enough to reach where your thighs actually touch, which usually means 6 inches or more. Fabric affects how it feels, but leg length decides whether it works at all. Flissie women's bamboo boxer shorts (we make them) have a 6 inch leg that stays put, in UK 8 to 30.
Does hiking underwear need to be seamless?
It helps, particularly under a pack hipbelt where the waistband is compressed. Flat, bonded or seamfree edges are all better than overlocked seams. It matters less than leg length if your problem is chafing.
How many pairs should I take on a multi-day hike?
Two or three, and rinse as you go. This is the main practical reason merino is worth the money on longer trips: it dries overnight and does not hold odour, so two pairs go further than three of anything else.
What underwear is best under walking trousers?
Something with a flat waistband that does not sit exactly where your trouser waistband or hipbelt sits, and a leg long enough that nothing rides up over several hours. Both problems get worse with distance rather than better.
Are boxer shorts good for hiking?
Yes, if your thighs rub: a boxer leg of 6 inches or more reaches where thighs touch, and a brief, bikini or hipster does not. REI's guide to hiking underwear says the added coverage of boxer briefs can often help reduce inner-thigh chafing. Flissie women's bamboo boxer shorts (we make them) have a 6 inch leg that covers the top of the inner thigh, in UK 8 to 30.
Is bamboo underwear good for hiking?
For a warm day walk, yes: bamboo viscose is buttery soft, breathes well and moves moisture rather than holding it, so it feels cooler than a synthetic on a warm climb. Flissie women's bamboo boxer shorts (we make them) add a 6 inch leg that stays put, in UK 8 to 30. For a multi-day trip where you wash as you go, merino dries faster.
How much does good hiking underwear cost?
From £13.50 to £36 a pair for the five here, checked on 7 October 2026 (ours on 11 November 2026): Boody's 6 inch undershort is £18, Flissie women's bamboo boxer shorts (we make them) are £13.50 a pair (£11.50 in a 10 pack), Runderwear's long boxer is £23, Smartwool's Everyday Merino Bikini is £31.99 and Icebreaker's Siren Hipkini is £35.99. Merino costs the most, and earns it on a multi-day trip.
Does merino underwear stop chafing?
Not if your thighs rub. Every merino option here is a brief, bikini or hipster, and all stop well short of where thighs touch; merino's strengths are dry speed and odour resistance on a multi-day trip. For thigh rub you need a long leg, such as the 6 inch leg of Flissie women's bamboo boxer shorts (we make them) or Runderwear's 8 inch long boxer.
Sources
Prices, ranges and policies were checked on each brand's own UK site on 7 October 2026, and prices change, so check before you buy. We have no commercial relationship with any of these brands.
- Icebreaker Women's Merino 150 Siren Hipkini
- Smartwool Women's Everyday Merino Bikini
- Runderwear Women's Running Long Boxer
- Runderwear returns policy
- Runderwear chafe-free guarantee (checked 8 October 2026)
- Boody Seamfree Undershorts, 6 inch
- CleverHiker, Best Hiking Underwear for Women (updated 24 August 2026)
- REI, How to Choose Hiking Underwear
The 60 Day Wear Test
Ready for your next long walk?
Try Flissie women's bamboo boxer shorts for 60 days. If they ride up, rub or roll, you get a full refund, worn or not.
Choose my pair£13.50 a pair, or £11.50 in a 10 pack. Free UK delivery. Return postage is at your cost.
Written by Phillippa and Matthew, the founders of Flissie. We make the Flissie women's bamboo boxer shorts on this page.
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