I tried the new trend for workout onesies, and it was so practical and fun I never want to go back to leggings

• I tried the new trend for workout onesies to see if they're worth the money.
• The Gymshark all-in-one I chose was fun to wear and really practical for all different workouts.
• It was comfier than leggings and sports bras, and at $38, definitely worth the money.

I love a one-piece. Dungarees, jumpsuits, playsuits, leotards ... I find it incredibly comfortable not having any constriction around my waist.

So when I saw the new (well, sort of new - they're something of a throwback to 80s-style unitards) trend for workout onesies, my interest was immediately piqued.

After spotting an increasing number of fitness influencers rocking all-in-ones for their workouts - not to mention tennis legend Serena Williams wearing a catsuit at the Australian Open - I knew I had to give it a try.

I wondered, however, if they would actually be practical, or simply yet another way for activewear brands to get us to part with more cash.

I decided to buy the Gymshark Flex All In One, which cost £28 ($38) on the UK site and was reduced from £40 (currently retailing for $50 on the US site) - Gymshark is one of the most popular activewear brands on Instagram, but I'd never actually tried any of its clothing.

Reader, I'm a onesie convert. I wore it for various different types of workout, and found my all-in-one practical, comfortable, and somewhat amusing to wear.

It was comfy, fun to wear, and made me want to move

My first impression upon seeing my reflection in the onesie was: I look like an Olympic swimmer.

Various brands do full-legged all-in-ones, which would probably minimize this vibe though.

It was a snug fit and there was no hiding my VPL, but it was very stretchy and comfortable.

However, there was no built-in sports bra or bust support. If you were going to do high-intensity exercise, and especially if you have a larger bust than me, you'd definitely want to wear a sports bra underneath, which would slightly ruin the aesthetic too.

I do think you need to be pretty confident in your body to wear something like this - if you're self-conscious about your "hip-dips" or whether your stomach is flat or not, it's probably not one for you.

If I wore the onesie to an exercise class or the gym, I imagine I'd receive mixed reactions, but in my own apartment at least, I felt awesome in it. It felt fun! And definitely made me want to move.

It's practical for working out

One of my pet peeves is leggings that fall down during a workout - and so many of them do. The beauty of the onesie is that this issue is completely removed.

I wore my onesie for various different workouts to put it to the test properly: weight-lifting, yoga, dancing, and P.volve classes.

Pleasingly, it was completely squat-proof - you don't notice until you bend over that the material actually changes over the butt: it's more opaque, and then more mesh-like over the rest of the legs, which feels nice and breathable.

It was very easy to move in, and felt particularly good when stretching or performing side-bends - I could move completely freely without worrying about anything falling down or digging in.

Not needing to fuss over my outfit actually meant I could forget about what I was wearing and how my body looked, and simply focus on how I was moving.

Going to the bathroom, however, was a bit more of an effort: Being so tight, it was tricky to pull up and down over my shoulders, and - much like when you go out in a playsuit - you also feel peculiarly naked.

You need to feel confident to wear a workout onesie, but I'm a convert

Once I got over the fact that I looked a bit like I was about to dive into a pool and attempt a 400m butterfly, I loved wearing my workout onesie.

At $38, this was definitely one of the cheaper fitness onesies I found online - I know athleisure is expensive and it's essentially a full outfit, but I was surprised to find so many brands selling all-in-ones for over $100.

I thought the Gymshark onesie was definitely worth the money, and considering how practical it is, I don't think the trend is all style over substance.

Yes, it could do with chest support, and a slim pocket might be handy like some leggings have, but I definitely want to expand my workout onesie collection - perhaps a long-legged and even long-sleeved version for these colder months.

I've always been a leggings and sports bra kind of girl, but I think one-pieces might just be the future of fitness fashion (as well as the past - Jane Fonda knew what she was doing).