One-piece swimsuits

Start with how you will use the suit and how long it needs to last. If you swim often or spend a lot of time in hot tubs, chlorine resistance matters most, and a suit made of durable polyester lasts longest. If softness, shaping or bust support matter more to you, a suit in a softer stretch fabric is the better choice, but it usually wears out sooner with frequent use in chlorine. Then choose the cut: the back, the straps and the leg cut decide how the suit sits and how well it suits what you do in the water. The questions below cover each of these.

The back has a big say in how well the suit stays in place, how much support it gives and how free your shoulders are. There are many backs, and their names differ between brands and even within the same brand, so it pays to look at the shape of the back rather than its name. As a rule, the more fabric in the back and the more closed it is, the more coverage and support it gives. The more open the back, the more freedom of movement for your shoulders and shoulder blades.

On training suits the back is designed around the swimming stroke, often with straps that meet between the shoulder blades or an open back with thin straps. Suits meant to give more support often have a more closed back and wider straps, and some backs are designed specifically to support the bust. Many backs have adjustable straps so you can adapt the fit to your body. If you are unsure, try on a few different backs.

The straps hold the suit up, carry part of the weight of the bust and, together with the back, decide how the suit sits on your shoulders. Whether they are thin or wide, fixed or adjustable depends on what the suit is designed for.

Thin straps are light and give your shoulders the most freedom, and they are common on open-back suits. Wide straps spread the load over a larger area and give a steadier, more secure fit, and they are common on suits with a built-in bra or shaping and on suits for a larger bust. On training suits the straps are often fixed and part of the back, so there is nothing to adjust. Adjustable straps let you adapt the fit to your body and take pressure off your shoulders, for example if you have a long or short torso or want more bust support. If the straps dig into your shoulders or slip off, the cut or the size is probably not right for you.

A training suit is designed for frequent swimming and the movement of the stroke. It is usually made of durable polyester that resists chlorine well, fits snugly so it does not shift in the water, and has a back and straps that leave your shoulders free. The fabric feels firmer and gives less than softer stretch fabrics. A regular one-piece puts more weight on softness, cut and support. The difference is not always chlorine resistance, though, as many regular one-pieces are also made of chlorine-resistant fabrics. If you swim often or spend a lot of time in hot tubs, choose a suit that resists chlorine well. The Women's swimwear page explains the fabric differences in more detail.

The leg cut is how high the suit is cut up over the hip. A high cut shows more of the thigh, makes the legs look longer and gives the most freedom of movement, but covers less of the hips and bottom. A low or medium cut covers more. If you also want to cover the top of the thighs, legsuits are the option. The cut is easiest to judge from the product photos.

No, not always, but lining does three things: it makes light fabrics and light colors opaque when the suit is wet, gives a firmer feel and extra support, and protects the outer fabric. Many suits are lined at the front, and shaping suits often have a control mesh inside over the stomach. Training suits are often lined only at the front.

For school swimming and swim training, a swimsuit made of durable polyester is best, because it resists chlorine longest and keeps its shape. The suit should fit snugly so it does not fill with water and the straps do not slip. All our girls' one-pieces are on the girls' one-piece swimsuits page, and the product pages have a size chart.