She has invited her fans into her home for a week as she sleeps, cooks and hangs out with friends, as part of a new experiment to promote her album Witness.

And Katy Perry’s latest antics involved her working up a sweat with personal trainer to the stars, Tracy Anderson, from inside the Witness Worldwide house.

The pop princess joined by sisters, Erin Foster and Sara Foster, best known for playing Naomi Clark’s sister Jen in 90210, to join her for her workout.

Katy flaunted her fantastic figure in a purple sports bra and matching lavender leggings.

The figure-hugging look clung to her slimline physique, showcasing her toned arms and flat stomach.

Her blonde crop boasted a blue tint, giving her look an edgy vibe.

Sporty style: Katy flaunted her fantastic figure in a purple sports bra and matching lavender leggings

Gym-honed: The figure-hugging look clung to her slimline physique, showcasing her toned arms and flat stomach

Katy was seen dancing around her house, posing up against a pillar and tucking into some cartoon face shaped pancakes.

Amid cooling down after her workout, the Teenage Dream hitmaker was also seen playing with her cute dog Nugget.

This comes as Katy offered a tight-lipped smile during her Today interview when Natalie Morales mentioned Taylor Swift, with whom Katy has famously feuded.

When Natalie prodded: ‘So her releasing her back catalogue of music on streaming services the same day your album, you – ‘ Katy replied: ‘I don’t know.’

Natalie pressed her: ‘It didn’t bother you?,’ but the singer responded only: ‘I don’t know. I could only do me,’ in the interview that aired on Monday.

Katy had rolled out Witness, the album in question, on Friday, and the record’s got a track called Swish Swish, featuring Nicki Minaj and a jubilantly vindictive lyric.

Bend and stretch: Fans got to watch her work out from every angle in the house that was covered with 41 cameras

‘Don’t you come for me,’ Katy taunts in the song. ‘No, not today. / You’re calculated. / I got your number. / ‘Cause you’re a joker. / And I’m a courtside killer queen.’

Natalie had pointed out that the song ‘sounds like, though, there – it is a response to someone, Taylor Swift, and that has been a constant story of – ‘ but Katy interjected.

‘That might be your story,’ she said, ‘but my story, which I know is true for me, is that I’ve had just not one person bully me, or one person hold me down, or, you know, met one troll,’ the Santa Barbara native noted.

Awkward: This comes as Katy offered a tight-lipped smile during her Today interview when Natalie Morales mentioned Taylor Swift, with whom Katy has famously feuded

Puppy love: Amid cooling down after her workout, the Teenage Dream hitmaker was also seen playing with her cute dog Nugget

Bundle of fluff: Katy beamed with delight as she fussed over her cute pooch