Men's Athletic Shorts

Athletic shorts are built around two features you cannot see from the outside: a liner and a synthetic fabric that does not absorb water. The liner is a mesh or knit brief sewn into the waistband. Its job is to hold everything in place so you can wear the shorts with nothing underneath. Doubling up with underwear defeats it and creates exactly the seams and folds that cause chafing.

Fabric splits into two families. Woven shorts use a thin, crisp polyester or nylon that rustles slightly, sheds wind and dries fastest, which suits running. Knit shorts use a soft polyester jersey that feels like a t-shirt, hangs heavier and moves less freely, which suits weights and general gym use. Inseam then sets what you can do in them, since 3 to 5 inches allows a full running stride while 7 to 9 inches covers squats and machines without riding up. A split hem, where the outer seam is left open for the last few inches, exists purely to let the thigh travel further on a sprint.

Woven cotton shorts, chino or denim, soak sweat and hold it against you, making them the wrong garment for anything that raises your heart rate. Cargo shorts add pockets and weight where movement wants neither. Swim trunks look similar and carry a liner too. But their fabric is chosen to shed water rather than to move vapor, and a mesh swim liner chafes badly over a long run. These are the only shorts in the drawer whose inseam is picked for range of motion instead of appearance.

Anyone training will want a pair, and so will anyone who likes shorts they can rinse in a sink and wear again the next morning. Hot and humid weather favors the shorter woven versions, while air-conditioned gyms make the longer knit ones comfortable. Restaurants, offices and anywhere with a dress code are out, since an elastic waistband and a drawcord read as gym clothing however clean they are. Buyers who dislike liners can find unlined versions, at the cost of having to wear something underneath.

Run through a full range of motion before buying, because a liner that rides or a hem that grips only gets worse under load. Hunt for a zip pocket, since a phone in an open pocket swings and bounces the moment you start running. Wash cold after every wear and keep fabric softener away, as it coats the fiber and destroys the moisture transfer these shorts depend on, then air dry rather than tumble, because heat kills the elastane in the waistband.