Gym underwear shouldn’t need a mid-set adjustment. For most men, the useful features are a steady fit, fabric that manages sweat, and enough support without squeeze.
Here are five options by workout and comfort preference, starting with SLY Collective’s bamboo boxer briefs and their hammock-style pouch.
1. SLY Collective Bamboo Boxer Briefs
For men weighing what underwear to wear to the gym, SLY Collective’s bamboo boxer briefs pair a close fit with a supportive pouch and longer legs. They’re a fit for training where thigh rub, sweat, or shifting fabric tends to distract you.
The 95% bamboo viscose is naturally moisture-wicking. The boxer briefs also have an anatomical hammock pouch, smooth sides, and a longer-leg cut. That mix addresses three common annoyances in one garment: damp fabric, skin rubbing against skin, and legs that creep upward during movement.
The hammock pouch is designed to hold and separate rather than flatten everything against the body. That distinction may suit men who want support without the compressed feel of tight compression shorts. The longer legs add coverage for squats and lunges, while smooth sides reduce bulky side seams against the skin.
You’re paying for a specific pouch and anti-chafe construction, not just a different fabric.
If thigh friction is the main issue, compare the cut with men’s underwear styles for gym workouts before you choose. Fit still matters: the legs should stay put without digging into your thighs.
2. Moisture-Wicking Synthetic Boxer Briefs
Synthetic boxer briefs are a sensible option for sweaty circuits, intervals, and sessions where fast drying matters most. Look for a close fit that stays in place, but doesn’t pinch when you bend or step into a lunge.
Choose a pair that feels comfortable when you move straight from a cardio warm-up into strength work.
Fabric alone won’t prevent chafing. Seams matter too. Flat seams or a smooth surface can reduce rubbing during repeated movement, while loose fabric may bunch under shorts. The waistband should sit securely as you run or change direction, without rolling or pressing into your waist.
There’s a trade-off. Synthetic fabric can feel less soft than bamboo against the skin, depending on the knit and fit. And moisture-wicking doesn’t mean sweat disappears. If a pair feels damp after a hard session, change out of it and wash it rather than wearing it through the rest of the day.
For a bamboo option and notes on managing sweat, our guide to underwear for sweaty conditions covers the fabric and fit questions to check. A synthetic pair is a good candidate if drying speed outranks a softer feel.
3. Long-Leg Anti-Chafe Boxer Briefs
Long-leg boxer briefs suit runners, cyclists, hikers, and anyone whose thighs rub during movement. The extra fabric covers more of the inner thigh, where repeated contact can become irritating over a long session.
Running creates repeated up-and-down movement, so a cut that stays in place matters as much as the material. Choose a close fit with smooth seams. If the leg hem rides up or folds, it can add friction instead of reducing it. Try a jog or a set of lunges when checking fit.
For cycling, look for a smooth surface where the underwear meets the saddle. Repeated contact can make rough seams uncomfortable, especially on longer rides. Hiking brings another test: a pack and warm weather can mean hours of movement, so a waistband that stays flat and fabric that doesn’t bunch are worth checking.
Long legs can also feel like too much fabric under short gym shorts, and they may be warmer than a brief or trunk. They’re most useful when thigh coverage solves a problem you already have. SLY Collective’s longer-leg boxer briefs are one option in this cut, with an anti-chafe design and smooth sides.
For a closer look at how coverage and fit relate to men’s workout underwear, see workout underwear options for men. If your thighs don’t rub, a shorter style may feel lighter and less warm.
4. Supportive Fitted Trunks
Fitted trunks have shorter legs than boxer briefs, which makes them a useful choice for lifting in shorter gym shorts. They sit close to the body and give front support, with less material around the thighs.
During squats and deadlifts, look for a waistband that stays level as your hips bend. The fit should hold without squeezing. A trunk that digs in at the waist or pulls at the crotch can turn a set into a distraction. Stretch fabric helps the garment move with you, but a shorter leg won’t cover as much inner thigh.
That last point is the main limitation. If you get chafing on long walks or runs, trunks may leave the rubbing area exposed. If your main frustration is excess fabric bunching under shorts, though, their shorter cut may feel cleaner. Choose by where you feel friction, not by the style name alone.
Material changes how a trunk feels during training. Cotton can feel familiar and soft, but basic cotton underwear may stay damp longer after heavy sweating. For longer, sweatier sessions, check whether the specific pair states that it wicks moisture.
Trunks work well for a gym floor session built around strength work, especially if you prefer less leg coverage. Try them under the shorts you normally lift in. A smooth waistband and a leg opening that doesn’t pinch are better signs than a tight, compressed feel.
5. Breathable Briefs
Briefs are a low-bulk choice for short, high-sweat workouts. With no leg fabric, there’s nothing to ride up against your thigh, and the cut leaves your legs free during cardio or fast-paced classes.
Look for performance fabric if you tend to sweat heavily. Breathable mesh or a quick-drying synthetic blend can help manage moisture during the session. The waist and front should feel secure, but briefs won’t give you the thigh coverage of boxer briefs. If your skin rubs where your thighs meet, this may not be the cut you want.
For lifting, briefs can work under short training shorts when you prefer a minimal base layer. For running, the lack of leg fabric means there’s no hem to fold or creep upward. Still, test the fit with your actual workout gear. Some men prefer the added sense of coverage from boxer briefs, particularly on longer sessions.
Don’t assume a label such as “breathable” means the fabric will suit every workout. Check the material details and look for a clear moisture claim. Fabric thickness and seam placement affect feel too. A thick seam in the wrong place can rub even when the brief itself fits closely.
To compare fabric terms such as moisture-wicking and quick-drying, SLY Collective’s notes on moisture-wicking underwear give you details to look for on a product page. Briefs are the leanest option here; coverage is the cost of that minimal feel.
Compare the Gym Underwear Options at a Glance
Use this quick view to match the cut to your training and the discomfort you want to avoid. Fabric claims vary by pair, so check the label before buying.
| Option | Works well for | Main advantage | Watch for |
|---|---|---|---|
| SLY Collective bamboo boxer briefs | Mixed training, running, leg day | Hammock pouch with longer-leg coverage | Costs more than basic multipack styles |
| Synthetic boxer briefs | Intervals, HIIT, sweaty sessions | Quick-drying fabric options | Check seam feel and fit |
| Long-leg boxer briefs | Running, cycling, hiking | More inner-thigh coverage | Can feel warm or bulky |
| Fitted trunks | Lifting, short gym shorts | Close fit with shorter legs | Less thigh coverage |
| Breathable briefs | Short cardio or high-sweat sessions | Minimal fabric around the legs | Won’t guard against thigh rub |
Frequently Asked Questions
What underwear should men wear to the gym?
Most men can start with close-fitting boxer briefs made from moisture-wicking fabric. For what underwear to wear to the gym, consider whether you need pouch support or extra thigh coverage. A longer leg can help when your thighs rub, while briefs or trunks suit men who prefer less fabric. The fit should stay secure without digging in.
Are cotton briefs good for working out?
Cotton briefs can feel soft, but they may hold moisture longer than quick-drying performance fabrics. For a short or low-sweat session, comfort may matter more than drying speed. For a hard cardio workout, check for a specific moisture-wicking claim or consider a synthetic blend. Fit and seam placement still affect comfort.
Are boxer briefs or trunks better for the gym?
Boxer briefs give more thigh coverage, while trunks have shorter legs and less fabric. Boxer briefs may suit running or leg day if you’re prone to thigh chafing. Trunks can feel less bulky under short training shorts. Neither cut is right for everyone, so check that the waistband and leg openings stay comfortable as you move.
How many pairs of workout underwear do I need?
Have at least one clean pair for each workout between laundry days. If you train four times before doing laundry, four pairs let you avoid rewearing a sweaty pair. Add a spare if you travel or sometimes fit in an extra session. You don’t need a large rotation if you wash regularly and your pairs dry in time.
When should I replace gym underwear?
Replace a pair when the waistband loosens, the fabric loses its shape, seams fray, or support no longer feels steady. Those signs matter more than a fixed calendar date because wear depends on how often you train and wash each pair. Follow the garment’s care label, and avoid high heat if it can damage stretch fibres.
Conclusion
If you want one pair for varied training, start with bamboo boxer briefs that combine a supportive pouch with longer legs. Check the size and fit against your usual workout, then explore SLY Collective to see the current styles and pack options.