Best Underwear for the Gym: Chafing, Sweat and Support Explained

Training in the wrong underwear is one of those problems nobody warns you about until it's too late. Here's what actually matters when you're picking underwear for the gym, not just what marketing copy claims.

Moisture-Wicking Actually Matters

Cotton absorbs sweat and holds onto it, which is exactly what you don't want during a session. Moisture-wicking fabrics (usually polyester or nylon blends) pull sweat away from the skin to the fabric surface where it can evaporate, keeping you drier for longer.

This isn't just comfort — prolonged dampness against skin during exercise is a major contributor to chafing and irritation.

Fit Prevents Chafing More Than Fabric Does

A snug, supportive fit that doesn't shift during movement does more to prevent chafing than fabric choice alone. Look for:

• A fitted (not loose) leg — loose fabric bunching and rubbing is a bigger chafing cause than tight fabric
• Flat, seamless construction at high-friction points like the inner thigh
• A waistband that stays put — one that rolls or slides means constant readjusting and rubbing

Boxer briefs with a longer leg tend to outperform shorter trunks or boxers here, simply because more of the thigh is covered by smooth, fitted fabric rather than exposed to fabric-on-skin friction.

Support Without Compression Overkill

You want support that holds everything in place during movement (squats, running, HIIT) without the tightness of full compression gear. Most well-designed boxer briefs strike this balance without needing a dedicated "compression" garment.

What to Avoid

• 100% cotton for high-intensity sessions — it gets heavy and damp fast
• Loose boxers for anything involving squats, lunges, or running — more fabric movement means more friction
• Worn-out elastic — a stretched-out waistband that's stopped gripping properly causes more shifting (and chafing) than a snug newer pair

The Short Version

For training days: fitted, moisture-wicking, longer-leg boxer briefs beat loose cotton every time. Our Breeze range is built specifically around breathability and movement, or browse the full men's underwear collection to compare fits.