10 of the best sports swimsuits for cross training and triathlons

The much-loved HyperBoom Muscleback is one of Speedo's most popular women's swimsuits. It fits wells, offering good coverage across the chest, and the muscleback design offers plenty of flexibility, so you can really lay the hammer down during your freestyle intervals.

The Endurance + fabric is plush and stretchy, and the brand say it retains its shape and resists fading longer than any other swim material. It's 100% chlorine resistant and offers UV protection.

Another entry from Speedo. With its high neck and zip-up back design, the brand's Hydrasuit offers a flattering yet full coverage option, making it ideal for those with a larger bust (there’s even a bust shelf liner for added security).

There’s no security tab at the top of the zip (like you’d find on a wetsuit) but our tester hasn't had any issues with the zip coming undone during a pool session. In fact, they described it as their ‘perfect fit’, with a high cut leg allowing for total flexibility in the pool. The suit’s EnduraFlex fabric also offers higher chlorine resistance than standard swimwear fabrics.

Make sure you size up, though, as it does run small. Our tester is a UK size 10 but opted for a size 12 (34 in Speedo) and found this fitted best.

One of our testers has been using this Aleumdr swimsuit for the past two years and still claims it's the most supportive one piece they own for tackling lengths in the pool.

The round-neck design, cross-back and lightly padded cups make it a great option for those with larger breasts. And for less than £30, the fit is excellent, too — it doesn't ride up and maintains its shape and fit, even after multiple washes. Plus, there's plenty of patterns available.

If you're unsure which size to go for, we'd recommend going for the larger option. Our tester wears the M (UK 12-14) and it fits perfectly.

A firm favourite among competitive club swimmers, you'll need to get your measuring tape out or Best for full coverage with this one, as it's part of Nike's performance swimwear range, designed for those who are taking their swimming training seriously.

The skinnier straps won't be supportive enough for larger-breasted swimmers but are tough and durable for those who can deal with a light amount of support.

Available in olive, black and bright red, this swimming costume from British-owned sustainable brand Davy J is one of our absolute favourites. Featuring a flattering square neckline, medium-to-high cut leg and cross-back straps, this cozzy feels super thick thanks to its double-lined fabric, which is made using 100% regenerated nylon yarn and provides serious compression and hold. We love it for The best arm sleeves for autumn running.

This is one of the best supported swimming costumes we've tried. It has built-in foam cups providing good breast support and also offers extra support around the middle; this not only aids comfort but gives a more flattering fit, so you feel confident in and out of the water. Available in a range of funky patterns and colours.

This seasuit from sustainability-focused brand Finisterre is made from recycled plastics, gives full-body coverage, offers SPF50+ protection and is designed to go in all water, from pool to sea. The loose cut is designed to avoid the suit being skintight, but it also means there is room under it for a wetsuit. There is a built in bra shelf and the geometric pattern is there to distort the contours of the body. Finisterre also do a matching Hijab.

As part of M&S's GoodMove collection, this supported swimming costume has been designed to feel flattering whether you're swimming lengths or chilling poolside. With padded cups, it gives you all the support you need to get through your session, and thanks to the brand's Secret Slimming technology, it holds your tummy in and shapes your waist for a flattering fit.

The zip-front makes getting the swimsuit on and off a little bit easier, plus the fabric is chlorine-resistant, meaning it should keep its shape and stretch.

If you're looking for a little extra coverage from your swimsuit, this Speedo legsuit ticks all the right boxes. There's also in-built bust support for comfort and a four-way stretch for ease of movement in the water. The legsuit is also fully chlorine-resistant and Speedo's Endurance+ fabric is designed to retain its shape and resist fading for longer.

This Roxy one-piece is perfect for swimming outdoors this summer. The long-sleeve design offers extra protection from the waves and the sun, while the swimsuit itself has UPF50+ protection. An easy back-zip closure makes it simple to get on and off, too.

It doesn't mention being chlorine-resistant, so this might be one you save for swimming in the sea.