Running is a liberating activity that pushes your body and mind, but everyone from beginners to marathoners knows that the little details—like your choice of running underwear—can make or break your experience. In fact, discomfort or chafing can turn even the flattest, sunniest trail into an ordeal. That’s why knowing what underwear to wear when running is essential for performance, comfort, and focus. Whether you prefer briefs, boxers, or compression shorts, or you’re curious about innovative technical fabrics and sustainable options, this in-depth guide will cover everything you need to know.
Table of Contents
1.Why the Right Underwear Is Essential for Runners
2.Underwear and Running Shorts: Do You Really Need an Extra Layer?
3.Key Benefits of Quality Running Underwear
4.Factors to Consider When Choosing Running Underwear
5.What Underwear to Wear When Running: By Gender and Preference
6.Making the Right Choice: Key Scenarios and Special Needs
7.The Best Running Underwear of 2025: Top 12 Picks for Men & Women
8.How to Choose the Best Running Underwear: Complete Buyer’s Guide
9.Frequently Asked Questions (FAQ) About Underwear for Running
Why the Right Underwear Is Essential for Runners
When it comes to running gear, most runners pay close attention to shoes, hydration packs, and even sunglasses. However, running underwear is often overlooked—despite its pivotal role in preventing skin irritation, promoting comfort, and optimizing athletic performance. The layer closest to your skin is crucial for several reasons:
Comfort is Key to Performance
Every stride sends vibrations and generates friction, especially over long distances. Performance underwear made from advanced technical fabrics provides the right balance of support and flexibility. It eliminates distractions so you can focus on your form, breathing, and pace. According to a 2023 Runner’s World survey, 82% of runners experienced discomfort or chafing due to improper underwear at least once during their training.
Quote from a marathoner:
"Once I switched to seamless, moisture-wicking running underwear, I finished my long runs feeling fresher and with zero chafe. It made a huge difference."
— Jamie L., Boston Marathon Finisher
The Risks of the Wrong Underwear: Chafing and Beyond
Wearing cotton or ill-fitting underwear during a run is a recipe for disaster. Cotton absorbs sweat rather than wicking it away, trapping moisture and increasing the risk of chafing, bacterial growth, and fungal infections. Non-athletic fabrics can ride up, bunch, or create pressure points, especially under running shorts or compression tights.
The Role of Underwear in Lined Running Shorts
You may wonder if built-in liners in “training shorts with liners” or “running shorts” replace the need for separate underwear. The answer varies:
● Brief-Lined Shorts: Designed for mild support and moisture-wicking, these work for some as a two-in-one option.
● Support: For longer distances, additional supportive underwear or compression short may still be beneficial.
● Hygiene: Removable, washable underwear offers more control over hygiene, especially in hot or humid climates.
Psychological Boost from Comfort
When you’re not thinking about seams, riding up, or wetness, you’re able to run more confidently. Running-specific underwear is engineered for optimal comfort, keeping you dry and confident during races, long training runs, and unpredictable weather.
Case Study: Olympic Athletes and Running Underwear
Olympic distance runners frequently cite the importance of custom-fit, moisture-wicking performance underwear as a non-negotiable part of their kit. A 2024 study published in the International Journal of Sports Science found that anti-chafe, technical underwear reduced skin irritation complaints by 67% in elite runners.
Table: Common Undergarment Problems and Their Solutions
Problem |
Cause |
Solution |
Chafing |
Cotton fabric, bulky seams, sweat |
Moisture-wicking, seamless stitching fabrics |
Odor |
Bacterial growth with poor wicking |
Odor control technical fabrics, quick-dry styles |
Ride-up/Wedgies |
Poor fit, loose leg bands |
Secure fit, elastane blends, gusseted crotch |
Skin irritation |
Synthetic blends or dyes |
Soft bamboo, merino wool, eco-friendly options |
Overheating |
Poor ventilation, thick seams |
Breathable panels, mesh inserts |
Lack of support |
Thin or loose design |
Compression shorts, snug athletic designs |
In summary: Choosing the right running underwear is a small decision with massive impact. From preventing painful chafing to enhancing support and overall athletic comfort, this often-overlooked layer can shape your entire running experience. In the next section, we’ll answer the popular question: Do you really need underwear with running shorts?—and explore the science behind built-in liners and technical fabrics.
Underwear and Running Shorts: Do You Really Need an Extra Layer?
A frequent debate among both novice and seasoned runners is whether you should wear underwear under running shorts, especially if those shorts come equipped with built-in liners. Some runners swear by the added layer for extra support and comfort, while others opt to go commando to avoid potential issues like bunching, moisture build-up, or chafing. So, what's the right choice when it comes to what underwear to wear when running?
The Built-In Liner Explained
Most training shorts with liners and running shorts are designed with an internal brief, boxer, or compression-style support layer. This liner is typically crafted from moisture-wicking, quick-drying materials like polyester, nylon, or spandex. Its purpose is to provide a barrier between your skin and the outer fabric, absorbing sweat and reducing skin friction.
Advantages of Built-In Liners:
● Moisture-wicking: Advanced technical fabrics in liners keep sweat away from your body, reducing the risk of blisters and fungal or bacterial growth.
● Reduced bulk: Liners eliminate the need for a second layer, minimizing potential hotspots where chafing might occur.
● Technical features: Features such as seamless construction, anti-chafing panels, and mesh ventilation improve breathability and comfort.
Disadvantages of Built-In Liners:
● Limited support: For long distances or runners needing added support, built-in liners may lack enough compression or secure fit.
● Fit Issues: A generic liner may not suit all body shapes, sometimes leading to riding up, wedgies, or poor coverage.
● Hygiene concerns: Since liners are attached, you can’t easily swap them out between runs, which may lead to odor or hygiene issues—especially in humid weather or on back-to-back training days.
Should You Still Wear Underwear With Built-In Liners?
Here’s where personal preference and run type come into play.
● Short Runs or Light Workouts: Many runners go commando, letting the technical liner handle moisture and support. This keeps things simple and often maximizes breathability.
● Long Distance or Sensitive Skin: For long-distance runners or those who are prone to chafing and irritation, wearing a specialized pair of running underwear under shorts adds a valuable layer of anti-chafe protection and support.
● Compression Shorts & Tights: When wearing compression shorts or tights, skip traditional underwear. Most compression wear is designed to be worn as an outer and inner layer combined, providing the necessary compression, moisture-wicking, and anti-chafe properties.
Expert Advice:
“The key to optimizing your running comfort is to test both options—commando or with running-specific underwear. Everyone’s anatomy and sensitivity are different. Performance underwear gives you a chance to find your perfect fit and function.”
— Dr. Maria Torres, Sports Medicine Specialist
Typical Scenarios
Scenario |
Recommended Option |
Rationale |
Casual, Short Runs |
Use liner only or moisture-wicking briefs |
Breathability, low risk of chafe |
Long Distance |
Add anti-chafe, seamless running underwear |
Extra layer for protection/support |
Hot, Humid Weather |
Quick-dry liner or technical running underwear |
Enhanced sweat and odor control |
Compression Tights |
No additional underwear |
Integrated support, reduces bulk and potential friction |
Factors to Consider When Deciding:
● Your unique shape and sensitivity to seams and fabric bunching
● The quality and comfort of your shorts’ built-in liner
● Climate: More layers may mean more heat; moisture management is crucial in warm weather.
● Laundry frequency: Built-in liners will need more washing if you go without a base layer.
Real Runner Stories
Case Study: Anna, a trail runner in Texas, used to suffer from frequent chafing during summer races:
"I always trusted the liner in my running shorts, but on longer, hotter runs, I started layering moisture-wicking briefs underneath. The difference in comfort and chafing was huge—no more raw spots or lingering irritation!"
Key Benefits of Quality Running Underwear
Choosing the right running underwear is about more than just adding another garment to your running clothing rotation. High-quality, purpose-built underwear delivers advantages that impact every run, from short city jogs to grueling long-distance marathons. Here’s why investing in technical, performance underwear pays substantial dividends in comfort, health, and performance.
1. Chafing Prevention
Chafing is the number one complaint among runners when it comes to underwear. Friction caused by rough seams, damp fabrics, or poor fit can create painful raw spots on inner thighs, groin, or waistband areas. Running underwear engineered with anti-chafe panels, flatlock or seamless stitching, and smooth technical fabrics such as nylon, polyester, or soft elastane dramatically reduces this friction.
● Fact: According to the American Academy of Dermatology, over 50% of long-distance runners will experience skin irritation and chafing at some point without proper gear.
● Features to look for: Look for underwear with no inner tags, seamless construction, and snug leg openings that stay in place.
2. Ultimate Comfort Without Adjustments
The last thing any runner wants to worry about mid-run is a wedgie, underwear bunching, or leg openings that ride up. Supportive underwear with a secure fit, elastic waistband, and smooth seams stays put regardless of terrain or intensity. This translates to zero distractions, faster pace changes, and more enjoyable training sessions.
Comfort Features Checklist
● Secure fit: No riding up, bunching, or slipping
● Soft elastane or bamboo viscose: Reduces skin irritation
● Flatlock or seamless stitching: Prevents hotspots
● Odor control: Built-in anti-microbial treatments
3. Odor Control & Enhanced Hygiene
Sweat is inevitable in running, but odor doesn’t have to be. High-quality running underwear uses materials with anti-microbial or odor elimination features. For example, merino wool naturally resists bacteria, while many synthetic blends include silver or copper-fiber infusions to combat odors.
4. Improved Performance and Support
Whether it’s compression shorts that enhance circulation and reduce muscle fatigue, or briefs with ergonomic support pouches, the right athletic underwear can help you run longer and recover more quickly. Compression increases blood flow, which aids in temperature regulation and speeds removal of metabolic waste from muscles.
Table: Core Benefits of Quality Running Underwear
Benefit |
Feature/Technology |
How It Helps |
Chafe Prevention |
Seamless/flatlock stitching, smooth fit |
Reduces friction, prevents skin irritation |
Moisture Management |
Moisture-wicking/quick-drying fabrics |
Keeps skin dry, limits bacteria and fungus |
Long-Lasting Comfort |
Secure fit, soft materials, no tag seam |
No distractions, no bunching or wedgies |
Odor Control |
Antimicrobial/odor-resistant materials |
Keeps you fresh after miles of activity |
Performance Support |
Compression, ergonomic design |
Better circulation, less fatigue |
Eco-Friendly |
Bamboo, recycled polyester/nylon |
Lower environmental impact, natural benefits |
What Underwear to Wear When Running: By Gender and Preference
Selecting the best running underwear isn’t a one-style-fits-all scenario. Men and women have different anatomical needs and comfort preferences, so your optimal underwear style will be influenced both by your gender and the typical conditions in which you run. Let’s dive into the choices and considerations for every runner.
The Best Running Underwear for Men
For men, the main priorities boil down to support, chafing prevention, moisture management, and maintaining a secure fit across all distances and conditions. The threat of thigh chafing (especially on long runs), unwanted movement, and moisture build-up are all common pain points addressed by purpose-built designs.
Common Styles for Men
● Boxer Briefs: The most popular option for active men. They combine the best features of briefs (support and containment) with extra coverage to prevent thighs from rubbing together, which is essential for chafe-free sessions.
● Briefs: Offer minimalist support and may appeal to men who favor a barely-there feel during short or very hot runs. Not ideal for endurance or runners prone to inner thigh chafing.
● Compression Shorts: Perfect choice for long distances, interval work, or trail runs. They double as both underwear and outerwear for some, further reducing friction and providing muscle stabilization.
Men’s Underwear Features to Look For
● Gusseted crotch for support and a comfortable range of motion.
● Flatlock or seamless construction to avoid skin irritation and chafing.
● Wide elastic waistband for a secure, non-pinching fit under running shorts or tights.
● Technical fabrics like polyester, nylon, or recycled blends for moisture-wicking and quick-drying performance.
Quote:
"Boxer briefs with seamless construction changed everything for my marathon training. No more chafing, even in 90-degree weather."
— David K., Distance Runner
Men’s Fit & Sizing Tips
● Always consult individual brand sizing charts.
● If you’re in between sizes or plan to run ultras/marathons, consider sizing up for breathability and comfort.
The Best Running Underwear for Women
Women face other unique considerations: a wider variety of body shapes, the need for both support and flexibility, and greater sensitivity to chafing in multiple areas (inner thighs, groin, buttocks). Some women must also factor in menstrual cycles, making supportive, absorbent, or leak-proof options a must for uninterrupted training.
Common Styles for Women
● Briefs: Offer moderate coverage and are a favorite for both short and long distances due to their reliable support and minimal seams.
● Hipsters and Boyshorts: Provide maximum coverage across the hips and buttocks, often with wider leg bands for anti-chafe performance.
● Thongs: Chosen mainly for zero panty lines, but only comfortable for short, low-intensity runs or walkers—minimal material may increase chafing risk over long distances.
● Compression Shorts: Double as both underwear and shorts, often with enhanced sweat-wicking, anti-chafe properties, and no slip during high-mileage sessions.
● Leak-proof or menstrual-friendly underwear: Includes specialized materials and gussets for menstrual cycle protection, keeping you comfortable and worry-free.
Women’s Underwear Features to Prioritize
● Seamless construction or flatlock stitching for softness in all sensitive regions.
● Breathable, quick-drying technical fabrics: Polyester, bamboo viscose, merino wool, or blends.
● High-waist vs. low-rise: Personal preference; higher waists add security and often prevent slippage on long runs.
● Wide, soft waistband: Avoids digging in and adds a smoothing element for all body shapes.
Sizing, Fit, and Comfort Advice
● Test different rises and cuts to discover what feels best for your body type and running style.
● During menstruation, consider performance underwear with built-in absorbency or pair menstrual cups/discs with well-fitted moisture-wicking underwear for extra protection.
Case Study:
Carla, a half-marathoner from Portland, switched to seamless hipster underwear made from recycled technical fabric:
"No wedgies, no chafing, and it even kept up with my toughest trail runs. I also love that it’s eco-friendly!"
Style |
Best For |
Support Level |
Chafe Prevention |
Moisture-Wicking |
Notes |
Men’s Boxer Briefs |
Everyday, long runs |
High |
Yes |
Excellent |
All-purpose, anti-chafe favorite |
Men’s Briefs |
Short runs, hot weather |
Moderate |
No/Low |
Good |
Minimalist, risks inner thigh rubbing |
Men’s Compression |
Ultras, marathons |
Very High |
Yes (full) |
Excellent |
Doubles as base layer/outerwear |
Women’s Briefs |
All distances |
High |
Yes |
Excellent |
Reliable, many breathable options |
Hipsters/Boyshorts |
Extra security/coverage |
High |
Yes |
Excellent |
Maximum coverage, flatter seams |
Women’s Thongs |
Zero panty lines |
Low |
No |
Good |
Best for short runs, use with caution |
Compression Shorts |
Racing, trails, periods |
Very High |
Yes (full) |
Excellent |
Leak-proof & seamless variants exist |
Making the Right Choice: Key Scenarios & Special Needs
Every runner is unique, and so are the demands of their running environment and goals. The best running underwear for a tenacious marathoner in rainy Seattle will differ from what a sprinter prefers in sunny Miami. By considering your special needs—distance, terrain, season, or personal sensitivities—you can really elevate your comfort and performance.
How to Choose the Best Running Underwear: Complete Buyer’s Guide
The best running underwear is the one that fits your body, supports your style of running, and withstands every climate and challenge you throw at it. Whether you prioritize comfort, chafing prevention, moisture-wicking, or sustainability, this buyer’s guide walks you through every consideration so you can confidently select the perfect pair.
Step-by-Step Guide to Finding Your Ideal Running Underwear
1. Assess Your Running Habits and Needs
● Distance: Are you running short, high-intensity intervals or training for marathons and ultramarathons?
● Climate: Do you face mostly warm, humid weather or cold, dry seasons?
● Terrain: Road vs. trail running raises different challenges for sweat, support, and durability.
● Frequency: Daily runners may need more pairs and durable materials.
2. Prioritize Your Must-Have Features
● Moisture-Wicking: Top priority for nearly all runners. This prevents sticky discomfort, skin irritation, and bacterial/fungal issues.
● Chafe Prevention: Seamless construction, soft edges, and full coverage are non-negotiable for chafe-prone runners.
● Support: Compression levels and design features (like a gusseted crotch or high-rise waistband) vary by gender and preference.
● Odor Control: Merino wool, bamboo viscose, or anti-microbial treated synthetics keep you feeling (and smelling) fresher.
● Eco-Friendliness: Look for certifications (like OEKO-TEX or GRS), recycled fabrics, and organic or bamboo materials.
3. Decide on the Right Style
● For Men:
○ Boxer Briefs — Most popular for all-around support and anti-chafe coverage.
○ Briefs — Good for hot climates or minimal coverage, but less chafe protection.
○ Compression Shorts — Ideal for longer runs, racing, or trail use.
● For Women:
○ Briefs — Balanced coverage, most widely chosen for comfort and support.
○ Hipsters/Boyshorts — Extra coverage and stay-put seams, especially for long runs.
○ Thongs — Good for zero panty lines, better for lower mileage.
○ Leak-proof — Menstrual-friendly options for peace of mind.
○ Compression Shorts — Dual-purpose for support and chafing prevention.
4. Test for Fit and Comfort
● Try the underwear with the running shorts or tights you plan to wear most often.
● Move in all directions—walk, squat, lunge, and jump. A good fit will not shift, pinch, or roll.
● Pay special attention to waistband comfort, leg openings, and overall coverage.
5. Don’t Ignore Durability
● Check product reviews for durability remarks.
● High-quality underwear should maintain elasticity, shape, and wicking properties through dozens of washes.
● Reinforced seams and technical stitching are especially important for frequent runners.
Quick-Reference Table: Choosing by Priority
Primary Concern |
Recommended Feature |
Best Material/Style |
Chafing |
Seamless, flatlock stitching |
Boxer briefs, compression |
Moisture-Wicking |
Technical fabrics, mesh panels |
Polyester, merino, bamboo |
Odor Control |
Antimicrobial, merino wool, bamboo |
Treated synthetics, merino |
Support |
Gusseted crotch, high-rise waistband |
Boxer/hipster/compression |
Sustainability |
Recycled, certified, OEKO-TEX fabrics |
Bamboo, recycled poly/nylon |
Menstrual Protection |
Leak-proof gusset, absorbent layers |
Specialized briefs/shorts |
Budget Conscious |
High value, durable, well-reviewed |
New Balance, Under Armour |