If I could only do one type of workout for the rest of my life, it would undoubtedly be swimming. But despite it being one of my most frequent workouts, I have always had a severe lack of swimwear that I feel good in and can get me through 50 lengths without any mishaps, which is why tracking down functional yet stylish swimwear has become my mission.

Of course there are your basic athletic swimming costumes available, and while they're great if you're a dedicated swimmer that values performance above all else, those of us who prefer a more gentle swimming workout may want something that you feel good in too - particularly if you like to spend some time lounging pool-side before or after your lengths.

I need swimwear that I know is in no danger of slipping out of place or falling down no matter what stroke I'm doing, that provides enough support around the chest, and I feel works for my shape and makes me feel good. When I feel good, I perform even better throughout my workouts and get myself into a better headspace.

As well as rounding up my own favourite pieces of swimwear, I've called on the expertise of Marie Claire UK's Senior Health Editor Ally Head, News Editor Jadie Troy-Pryde, and eCommerce Analyst Sophie Cookson, all of whom have put their respective swimwear through its paces during workouts and weekends away. These are the 12 pieces that we would recommend in a heartbeat, with your every need covered.

And if you also want to hit the gym floor or Reformer studio on non-swimming days, we've also compiled cool girl activewear brands, summer activewear trends, sports bras with pockets, and the best workout camis to see you through any sweat session.

This is easily one of the most comfortable swimming costumes I have ever put on. I have tried lots of one pieces that are a nightmare to get into, whether that be due to the cut or the fabric, but this couldn't have been more different. It's buttery soft and went on with no effort at all, but still provided ample support around my chest and didn't move or slip even after swimming multiple lengths in the swimming pool. And although it's a more classic cut, the square neckline, low swooping back and higher leg cuts give it that little something extra that sets it apart from the overly-sporty options on the market. It's the ideal middle ground for swimmers who want to look and feel their best.

On the days when I want to do a longer or slightly harder swimming workout, this Sweaty Betty costume has been my go-to. I opted to take the removable cups out as they did bunch up and shift out of place when I pulled the costume on or off, but I still had plenty of support without them in. The higher cut neckline and adjustable straps mean that I can really tighten it up to ensure it stays on firmly, and it has a modest bikini line that is very comfortable. I love that the leopard print makes this standard costume feel more special, and the subtle back cutout gives it that little something extra, too. With just the right amount of compression, it will suit both casual and serious swimmers.

"I've long been a fan of B Corp brand Chelsea Peers and their sustainably made, responsibly sourced active and loungewear, and their swimwear is great, too. I tested this crinkle stripe swimsuit in orange, and it's ideal if you're after a cute but practical option that offers more coverage than a bikini. It's got a flattering scoop neck and plunge back detail, an internal bust shelf and supportive lining, not to mention it's made from impressively stretchy fabric. While on holiday, I loved pairing this swimsuit with white linen trousers, Havaiana flip flops and an oversized woven bag for days exploring or by the pool - the Mediterranean inspired rust orange and off white colour palette feels very this season - but I also rate it just as much for chucking on for laps down at my local lido."

I really didn't expect this swimming costume to fit me right due to the thin straps and minimal back coverage, but I was so pleasantly surprised. It's a true elevated basic - it's understated but still special thanks to the criss-cross straps and exposed back. It's made from a soft Econyl® jersey that stretches nicely and provides a great level of support, which makes it a favourite of mine for holiday wear when I'll be doing a few lengths but not going too hard on my workout. The nature of the cut means it isn't the most suited to lengthy swimming pool sessions where you'll be doing multiple different strokes, but for a soft workout or if you're after a one-piece that isn't frumpy or too full coverage, it's ideal.

I rarely wear bikinis for my swimming workouts, but this may have swayed me. I was sceptical about following the size guide online, but it matched up perfectly to my bra size for a comfortable and supportive fit that genuinely feels like underwear. The high-cut bottoms also impressed me as they didn't move around or roll down, even when I bent over outside of the pool or twisted around. There was zero digging in, and the adjustable straps provided a customised fit. Plus, how gorgeous is this print?

"I've been quite blown away by the quality of the Monday activewear, clothing and, most importantly for this article, swimwear. While their Palma design looks like your standard run-of-the-mill triangle bikini set, it's really superior quality, has excellent staying power and washes well, too. When testing, I really rated that the bikini top offered a fully customizable fit with adjustable sliding cups and adjustable halter, plus that the bottoms offered just the right amount of coverage. That said, if you prefer lots of coverage for your swimwear, this design might not be for you, but IMO it's the perfect beachside set for if you know your time will be divided between sunbathing, swimming and watersports."

"There are so many swimsuits out there that are reliable and functional for proper swimming, but it can be hard to find one that is aesthetically pleasing and flattering. The two-toned high-cut leg meant that I could do lengths in the pool without the bottoms riding up and me having to adjust it. Similarly, the wide length, adjustable straps meant that it didn't ride down while I was swimming, which can usually be really annoying. I love how timeless this piece looks, whilst also being environmentally friendly by using PYRATEX® Active 1 materials and also being comfortable to swim in for long periods of time."

"I was dubious that I’d feel supported in this strappy swimsuit, but was pleasantly surprised by the strength in that cross-back drawstring (for reference, I’m a 34F and UK 14/16, and I tested a UK 16). It’s a great one piece for a leisurely swim - think gentle open water laps or holiday sea dips - and the material is both stretchy and sculpting. The ruching adds nice detail to the hips, and I also appreciated the ample bum coverage as I don’t love a thong cut."

"If you haven't heard of Australian swimwear brand bond-eye, let us put them on your radar. Designing crinkle swimwear in a range of shapes and sizes, I tested the Gracie Balconette and Scene briefs in red from their newly launched Bare Collection. I love that the range promises to redefine the line between swimwear, athleisure and ready-to-wear - who doesn't love wardrobe items that you can wear multiple ways, right? - plus, how gentle the seamless edges of the bikini were, excellent for sitting softly on, not digging into bare skin. The fabric is also next-level soft, offering unparalleled comfort that's also supportive and confidence-boosting, as you know the suit won't budge an inch."

Boux Avenue is one of the brands I recommend most when it comes to swimwear, as they go by bra sizes rather than the standard small, medium, and large. This is brilliant if you can never find swimwear to fit you, you require extra support around the bust, or you want swimwear that looks and fits like underwear. I have this one piece in black, and it's easily one of the items I feel my best in. It fits my bust perfectly, offers a lot of support around my middle, and stays firmly in place no matter what. The vintage design is so chic, and it really does suit everyone. The thick straps mean it can be trusted to stay firmly on my shoulders at all times, and I love the colour accents that elevate the look even more.

"This is my all-time favourite bikini - so much so, I've had mine for around three years now and have taken it on every holiday, beach trip or lido visit. Yep - it's fair to say it's had a fair bit of usage in the sea, swimming pools, saunas and more, and yet the quality is still as good as new, which IMO is seriously impressive. I love that the brand prioritises sustainable practices, but also that this Palma design in particular is super flattering and fashionable, not to mention genuinely stays in place and makes you feel supported during any activity. I've been swimming, snorkelling, and even kayaking in mine, and you almost forget you're wearing it, it's so seamlessly supportive."

"Vuori is a firm favourite in the athleisurewear world, with celebrities including Harry Styles, Oprah Winfrey, and Cindy Crawford thought to be fans - and I can see why. Their newly launched Heatwave Bikini is a redesign of the classic triangle bikini and has great staying power - no slipping down or riding up here - as well as offering an impressive four-way stretch. When testing, I particularly liked the bikini tops adjustable straps and back closure, ensuring the bikini fits just the way you want it to. Top tip, though: I'd go up a size and adjust to fit, as the bottoms in particular run a little small."