The runsie is going viral this season — here's our top 5 picks for summer training and racing

Hattie Parish, health and fitness e-commerce editor: Lightweight, breathable and flattering, this TikTok viral one-piece has split shorts and a crossover back for brilliant range of motion, while the peekaboo detail aids ventilation.

The shorts don’t ride up and have a comfortable brief liner underneath. The liner is black in darker shades of the onesie (excellent), but confusingly is white for the other colours, so can look a bit like you’re flashing your underwear.

There’s a wide, supportive waistband which houses a zipped pocket at the back – it’s big enough for cards and keys, but frustratingly not a phone.

Another drawback is that it's not supportive in the bust, so if you are running in it, you need a sports bra, and finding one that works with the cut-out detail and back straps is a bit of a challenge. But because of how cute and comfortable the piece is, I urge you to do so – or simply wear alone for long recovery walks/running errands.

FP Movement's Get Your Flirt On shorts have been another viral sensation lately – and this all-in-one Shortsie levels them up to a new degree. The form-fitting top half features a strappy back design, ticking all the boxes when it comes to style. Like the Righteous Runise (above), you'll need to wear a sports bra underneath it if you need more support, though. Oh, and there's six different colourways to choose from.

Don't sleep on 30% off the Launch Runsie from Under Armour. The fitted upper body is lined with mesh for ultimate comfort, with a high neckline that lends itself to wearing a sports bra underneath without it being overly visible. The loose woven shorts feature an inner brief, they're lightweight, and there's a secure, zip centre back pocket for storing your phone and keys. It's only available in one colour (for now), but can you really go wrong with classic black?

Not a fan of floaty shorts? Lululemon's Nulux Bodysuit oozes sophistication, with a contoured, body-hugging fit. Made from the brand's supremely soft Nulux fabric, it's sweat-wicking, breathable and quick-drying. A front zipper closure makes it easy to get on and off, too, and there's small premium touches like silicone grippers on the hem to stop it from riding up.

Coverage wise, there's no shying away from the fact that it's on the cheeky side, but if that's not a deal-breaker, this is a runsie that's sure to bring some power to your track sessions.

You'll have to act quickly if you've got your eyes on this all-in-one number, because it's part of a limited edition collaboration between New Balance and LA-based wellness collective Direct Vision (available from 23 May).

We love the high-coverage cut with the collar and slightly longer length of the bottom half (goodbye thigh chafe). There's also two zippered pockets – one on the left leg and one on the back – both big enough to hold a smartphone.

It's big and it's bold, and you'll need some confidence to pull it off, but we think it offers a fashion-forward take on race-day performance.