It depends on the intended use and personal preference:

• Briefs offer the least water resistance and are especially suitable for competitive swimming.
• Trunks/boxers are versatile, suitable for both swimming pools and beach vacations — they offer a little more coverage than briefs.
• Jammers are longer, knee-length models that are often used in training and competition to take advantage of hydrodynamics.
• The mid-jammer is a compromise: slightly shorter than the basic jammer but longer than the trunks.
• Swim shorts/boardshorts are casual, beach and leisure styles that often have pockets and a slightly looser fit.

• Measure your waist and hips in centimeters and compare to the manufacturer's size chart.
• If you are between sizes, choose a slightly larger size — a size that is too tight can pinch and restrict movement.
• Please note that models from different brands differ: the same “M size” does not necessarily mean the same sizing across different brands.
• The manufacturer's selection guide (e.g. Arena) also emphasizes length (leg length) as part of the decision.

Many trunks or shorts models have a mesh lining that provides support and prevents chafing.

Some models are not lined — this may be more comfortable, but may lack support and cause more skin irritation.
The choice depends on your own comfort: if you find an unlined model better without additional layers, that's also a perfectly valid option.

Rinse immediately after use with cold water to remove chlorine, salt and other chemicals. Wash with a mild detergent and not too often. Avoid harsh detergents which can reduce elasticity.
Avoid tumble drying or drying in direct sunlight — drying in the shade preserves the colors and fabric better.
Don't store even damp swimsuits in a closed bag for a long time — they can decompose or become moldy.

Common materials include polyester , nylon , and polyamide , often blended with elastane (Lycra/spandex).

Polyester-based materials are generally more resistant to chlorine and wear.
If you swim frequently, choose a chlorine-resistant fabric (brands like Arena use special chlorine-resistant materials).

Some technical competition designs use advanced fabrics that reduce water resistance and improve performance — but their use is restricted by competition rules.

For indoor swimming, it is a good idea to choose chlorine-resistant men's swimming trunks , such as briefs, trunks or jammers. Tighter-fitting pants are more resistant to active use and stay in place while swimming.