For lap swimming and swim training, a snug swim brief with a drawstring is the most practical choice: it creates almost no drag, stays put through tumble turns and push-offs, and dries quickly between sessions. If you prefer a little more coverage on the thigh, a fitted square-leg trunk does the same job with a slightly longer cut.
Why swimmers train in briefs
Loose board shorts are made for the beach, not the lane. Once they fill with water they pull at the waist, flap against your legs and slow you down on every length. A close-fitting brief moves with you instead of against you.
- Less drag: fabric that sits flat on the skin does not trap water.
- Freedom at the hips: nothing on the thigh, so your kick stays loose and long.
- A secure fit: a tied drawstring keeps the waistband in place when you push hard off the wall.
- Quick to dry: less fabric means less to carry home wet in your bag.
If you are still deciding between cuts, our comparison of swim trunks, swim briefs and board shorts covers the basics.
Features that matter in the pool
Most swim briefs look similar on a hanger. In the water, a few details decide whether a pair is a training partner or a beach-only piece.
A drawstring you can actually tighten
An elastic waistband alone can loosen after many sessions. A drawstring lets you fine-tune the fit before each swim. Look for one that ties at the front so you can adjust it while standing at the end of the lane.
Stretchy, quick-drying fabric
Polyamide blended with spandex or elastane is the usual training mix: it stretches in every direction for a full stroke and sheds water fast. Check the label of each style; the Arjen Kroos pieces below list their exact blend.
A lined or double-layer front
A second layer at the front gives a cleaner shape and more peace of mind when the fabric is wet. It is worth having if you train in a busy public pool.
Brief or square-leg: choosing your training cut
Both cuts work for laps. The choice comes down to how much coverage you like and how the fit feels during kicks.
| Swim brief | Square-leg trunk | |
|---|---|---|
| Leg coverage | None, fully open hips | Short panel on the upper thigh |
| Feel in the water | Lightest, almost unnoticed | Snug, slightly more structured |
| Best for | Regular laps, drills, longer sets | Swimmers who want a bit more coverage |
| Poolside look | Classic and sporty | Modern, works for the beach too |
The Slim Fit Square-Leg Trunks are made from 82% polyamide and 18% spandex with 4-way stretch and a drawstring closure, in four colours from S to XXL. The Square-Leg Swim Briefs use the same 82/18 blend, with an external drawstring over the elastic waistband and high-contrast colour panels, in eight colours from S to XXL.
Getting the size right for training
Training swimwear should feel firm on dry land. Fabric relaxes a little once it is wet, so a pair that feels slightly loose in the changing room can slide down after a few lengths.
- Measure your waist and compare it with the size chart on each product page; charts differ between styles.
- Pick the size where the waistband sits flat with no gap at the back when you bend forward.
- If you have muscular legs and like a looser leg opening, the Sport Swim Briefs page suggests trying one size up.
- Tie the drawstring before you get in, not after the first length.
Not sure which way to go? Our men's swim briefs guide explains how a good pair should sit.
Build a simple training rotation
If you swim two or three times a week, one pair is rarely enough. Wet swimwear left in a bag overnight never fully recovers its shape. A rotation of two or three pairs lets each one dry completely.
- Everyday training pair: a classic solid brief such as the Classic Swim Briefs, low rise, tagless, with adjustable drawstrings, in eight colours from S to XL.
- Light, airy pair: the Mesh Swim Briefs use a fine, breathable mesh fabric, a double-layer contoured pouch and a drawstring, in eight colours from S to XL.
- Coverage pair: a square-leg style for days when you want a little more on the thigh.
Care after every session
Pool water is hard on stretch fabric. A minute of care keeps your training pairs snug for longer.
- Rinse in cool fresh water straight after your swim.
- Press out water gently; do not wring or twist.
- Dry flat in the shade, away from radiators and direct sun.
- Wash by hand or on a gentle cycle as stated on the care label.
For more detail, read our men's swimwear care guide.
Frequently asked questions
Are swim briefs better than shorts for lap swimming?
For most swimmers, yes. A brief holds no water, does not cling to the legs and stays in place on turns, so lengths feel smoother.
Should swim briefs feel tight?
Snug, not squeezing. They should sit flat without digging in. Wet fabric loosens slightly, so a firm dry fit is normal.
Can I wear the same swim briefs for the pool and the beach?
Yes. All the styles in this guide work in both places. Just rinse them after each swim, whether the water was chlorinated or salty.
How many pairs do I need for regular training?
Two or three pairs is a good number if you swim several times a week, so each pair can dry fully before its next session.
Shop this guide
Ready for your next session
A well-fitting brief with a drawstring and quick-drying fabric is all you need to swim lengths in comfort. Browse the full range of men's swimwear, or look through our men's briefs for a matching pair to change into after training. Every order ships in discreet packaging.
