Best Men’s Running Underwear 2026: Anti-Chafe Picks for Long Runs
Running underwear has a simple job: stay put, manage sweat, and keep seams away from places that rub. The wrong pair can bunch after ten minutes. The right one disappears under your shorts.
For most men, a fitted boxer brief with a 5- to 6-inch leg is the safest place to start. Runners with bigger thighs usually need that extra coverage. If your shorts already have a comfortable liner, you may not need separate underwear at all.
Updated and fact checked: September 2026. Running Gear Lab may earn a commission if you buy through some links on this page. That does not change what you pay. Product names, colours, pack sizes, and availability can change.
Best place to start
Under Armour Performance Tech Mesh 6-Inch Boxerjock
This is the most balanced choice for everyday running. The close fit and mesh fabric make more sense for sweaty training than loose cotton, while the 6-inch leg gives useful thigh coverage without feeling like a full compression short.
It is a practical starting point for daily miles, warm weather, gym sessions, and travel. Check the listing carefully because Amazon can group different Under Armour underwear styles and pack sizes on similar-looking pages.
Before buying: confirm that the listing says Performance Tech Mesh and 6 inches. Choose the size that sits close without digging into the waist or squeezing the leg opening.
The quick answer
What underwear is best for running?
Choose a fitted synthetic or merino boxer brief that dries quickly, lies flat at the seams, and covers the part of your thighs that rub. Start with a 5- to 6-inch inseam. Use a compression short when you want more hold under unlined shorts.
Skip separate underwear when the built-in liner in your running shorts is comfortable and supportive. Adding another layer can trap heat and create more fabric movement.
Compare the six picks
These cards replace the old wide table, so the important differences are visible without horizontal scrolling on a phone.
Best for: most runners and warm-weather training
Fit: fitted boxer brief with a 6-inch leg
Check: exact model and pack size
Best for: a lower-cost training rotation
Fit: performance mesh boxer brief
Check: fabric, colour, and number of pairs
Best for: more hold under unlined shorts
Fit: tight training-short feel
Check: may feel warm under fitted shorts
Best for: bigger thighs and daily miles
Fit: 6-inch boxer brief
Check: fit and fabric can vary by pack
Best for: cool weather and travel
Fit: shorter merino boxer brief
Check: less thigh coverage than 6-inch picks
Best for: long runs and more front support
Fit: light compression with a pouch
Check: pouch fit is personal
Men’s running underwear reviews
Best overall
Under Armour Performance Tech Mesh 6-Inch Boxerjock
The Under Armour Boxerjock covers the needs most runners share. It fits close, uses an all-over mesh design, and extends far enough down the thigh to limit skin-on-skin rubbing for many men.
The 6-inch length is the useful middle ground. It gives more protection than a short trunk without feeling like a second pair of shorts. It can also move between running, gym sessions, and travel.
What works
- Useful balance of coverage and ventilation
- Close fit without a long compression-short feel
- Easy to use beyond running
What to check
- Similar UA listings may show different fabrics
- Pack sizes and colours can change
- Less structured than the SAXX option
Best budget multipack
Adidas Performance Mesh Boxer Briefs
The Adidas option makes sense when you need enough clean pairs for a normal training week. A performance-mesh boxer brief is better suited to sweat than loose cotton, and multipacks can keep the cost per pair reasonable.
Use this as a practical rotation pair rather than assuming it is the best choice for a marathon. Adidas listings can vary by retailer, colour, fabric blend, and pack size. Read the exact listing before buying.
What works
- Lower-cost way to build a rotation
- Suitable for normal weekday training
- Mesh fabric is more useful than cotton for sweat
What to check
- Exact model can vary between listings
- Confirm the number of pairs
- Less long-run specific than SAXX or Under Armour
Best compression style
Nike Pro Dri-FIT Fitness Shorts
Nike Pro is closer to a tight training short than everyday underwear. The close fit reduces loose fabric and gives more hold under light, unlined running shorts.
That extra coverage can be useful for faster running and lifting. It can also feel warm or bulky beneath shorts that are already fitted or lined. Treat the Nike layer and outer short as one system.
What works
- Secure feel with little loose fabric
- Useful under unlined shorts
- Works for running and strength training
What to check
- Warmer than a light boxer brief
- Can be too much under tight or lined shorts
- Feels more like a short than underwear
Best for bigger thighs
New Balance Premium 6-Inch Boxer Brief
The New Balance boxer brief is a sensible middle option. Its 6-inch leg gives more coverage than a short trunk, which can help when shorter underwear rolls up or leaves the inner thigh exposed.
This is a daily-training pick rather than a premium race-day choice. Multipacks are convenient, but retailer listings can use slightly different names and fabric blends. Confirm the inseam and materials before ordering.
What works
- Useful thigh coverage
- Practical for frequent training
- Often available in multipacks
What to check
- Fit can vary between pack versions
- Not as light as the coolest mesh options
- Less structured than SAXX
Best merino option
Smartwool Men’s Merino Boxer Brief
Smartwool is the choice for runners who prefer merino next to the skin. A merino blend can feel comfortable across changing temperatures and is useful for travel when you want fewer pairs in the bag.
The shorter leg gives less thigh coverage than the 6-inch picks. It may be comfortable for easy running and cool days but is a weaker match when your main issue is inner-thigh rubbing.
What works
- Soft merino-blend feel
- Useful for cool weather and travel
- Flat seams can reduce irritation
What to check
- Shorter thigh coverage
- Higher price than basic multipacks
- Less support than compression styles
Best long-run support
SAXX Kinetic Light Compression Mesh Boxer Brief
SAXX Kinetic is the most structured choice in this group. The light-compression fit and support pouch are designed to reduce movement when pace, sweat, and distance all increase.
The pouch is also the main fit question. Some runners like the separation and support. Others prefer a simple front panel. Check that the Amazon page shows the Kinetic Light Compression Mesh model rather than a related SAXX style.
What works
- More structure for longer runs
- Light-compression fit
- Breathable sport-focused design
What to check
- Pouch fit is personal
- Costs more than basic multipacks
- Related SAXX models can appear in search results
How to choose running underwear
Start with leg length
A 5- to 6-inch inseam gives most men useful thigh coverage without the heat of a long compression short. Go longer if your thighs still rub. Shorter pairs work best when thigh contact is not a problem.
Choose fabric for sweat
Loose cotton holds moisture and can bunch. Synthetic mesh, smooth stretch fabric, and lightweight merino dry more comfortably. This matters most on treadmills, warm days, and long runs.
Feel the seams
Check the front panel, inner thigh, waistband, and leg opening. Flat seams and smooth stitching reduce irritation once sweat and repeated movement are added.
Match support to the run
Easy miles may only need a fitted boxer brief. Speed work, gym sessions, and unlined shorts can feel better with compression. Long runs may benefit from a more structured pouch.
Do you need underwear under lined running shorts?
Usually not. A comfortable liner is designed to handle support and sweat on its own. Add separate underwear only when the liner is loose, scratchy, worn out, or not supportive enough. Our best running shorts for men guide separates lined and linerless choices.
Quick picks by runner type
Fit checklist before a long run
- Do a few bodyweight squats. The legs should not roll up immediately.
- Jog in place for 30 seconds. The waistband should stay flat.
- Check the inner thigh and front seams for rough stitching.
- Wear the pair on an easy run before using it for a long run or race.
- If the fit is good but one spot still rubs, apply anti-chafe balm before longer sessions.
Still getting chafing?
Underwear cannot fix every source of friction. A rough seam, loose waistband, hydration belt, or soaked shirt may be the real problem. The Best Anti-Chafing Products for Runners guide covers balms, creams, patches, and other options for problem areas.
How these picks were checked
We compared current product names, intended use, inseam length, fabric descriptions, support style, and retailer availability. We also looked for common reasons a pair may fail on a run, including short legs, bulky seams, loose fabric, heat, and inconsistent online listings.
Running Gear Lab has not personally tested every pair on this page. Recommendations are based on the product details available for this update and the fit problems each design is meant to solve. Test new underwear on an easy run before trusting it for race day.
Related running clothing guides
Men’s running underwear FAQ
What is the best underwear for running?
For most men, start with a fitted 5- to 6-inch boxer brief made from quick-drying synthetic fabric or lightweight merino. It should stay close without squeezing and cover the part of the thigh that rubs.
Should men wear underwear under running shorts?
Wear separate underwear under linerless shorts. If the shorts have a comfortable built-in brief or boxer liner, another layer is usually unnecessary. Add one only when the liner is loose, rough, worn out, or not supportive enough.
Are compression shorts better than boxer briefs for running?
Compression shorts give more hold and work well under unlined outer shorts. Boxer briefs feel lighter and suit most daily runs. Choose the least bulky option that stays in place and gives the support you want.
What underwear helps prevent chafing?
Look for smooth seams, a secure waistband, quick-drying fabric, and enough leg length to cover the area that rubs. A 6-inch boxer brief works for many men. Anti-chafe balm can help when the clothing fit is already correct.
What works best for bigger thighs?
Start with a close-fitting 6-inch boxer brief. The leg opening should stay down without cutting into the thigh. Very short trunks can roll up or leave more skin exposed.
How many pairs of running underwear do I need?
Four to six pairs is practical for someone who runs three to five days per week. That leaves a clean pair available without requiring daily laundry. Use the pair that fits best for long runs and races.
