She’s always been in good shape.

But yesterday Katy Perry showed off the results of her tough diet and exercise regime ahead of her wedding to Russell Brand as she enjoyed the slides at a water park in the Bahamas with friends.

The 25-year-old singer looked toned and svelte in a black and white bikini with red ribbon embellishments as she made her way around Atlantis Paradise Island in Nassau.

Toned: Katy Perry shows off her incredible bikini body as she walks around the Atlantis Paradise Island in Nassau, the Bahamas, with friends

Svelte: The 25-year-old singer appeared to be enjoying herself as she had a go on the slides and rides at the resort

Giggling with friends, Katy appeared to be making the most of her free time after performing a sell-out concert at the resort’s Grand Ballroom.

She waved to fans as she enjoyed the attractions at the water park with an entourage which included her brother David Hudson, her assistant Suzanne Sansone and stylist Logan Horne.

Before arriving in the Bahamas, Katy tweeted: ‘BERMUDA, BAHAMAS, CUMMON BABY MAMA!’

But, giving some hint to the pace of proceedings in Nassau, Katy later took to Twitter and added: ‘My friends are out of their mind!’

Slim: Katy has been sticking to a gruelling diet and exercise regime ahead of her wedding to Russell Brand later this year

Entourage: Katy was joined by friends including her brother Daniel Hudson and stylist Logan Horne

Katy, who is believed to be marrying fiancé Russell Brand in Goa in October, has been undertaking a gruelling fitness and diet regime to ensure she is in the best shape possible for her big day.

As well as regular trips to the gym, Katy is said to be following the 5 Factor Diet, which requires you to stick to eating five regular meals a day, with five ingredients per recipe and five minutes preparation time.

It has also been claimed Katy, who is thought to have dropped two dress sizes since embarking on the regime, is planning to wear a two-piece wedding outfit which will show off her toned abs.

Disguise? Katy conceals herself under a turquoise and white striped towel as she jokes around with friends

Usual behaviour: Katy’s friends didn’t seem to bat an eyelid at her bizarre disguise

And the California Gurls singer admits she has been in talks with renowned designer John Galliano about dressing her for the wedding.

She told America’s People magazine recently: ‘We have been kind of talking to Galliano because that was the first show in Paris that we kind of came out as a couple.

‘So if we did Galliano, it would make it full circle.’

Is that you, Katy? The singer relaxes in a giant rubber ring on the lazy river

While details of the couple’s wedding are being kept secret, Katy has said she does not want the ceremony to be in their usual outrageous style.

She added: ‘The wedding will be small. I always have a ton of people around me and I think the people that are going to share this moment with us are the people we want to integrate into each others’ lives.

‘We don’t want it to be a drunk fest of people, just one night and then forgetting about it. We want it to be about the love.’

Wedding plans: Katy and fiancé Russell Brand are planning to tie the knot later this year