Katy Perry is eager to increase her stamina.

The 'Roar' hitmaker, who is set to kick off her Prismatic World Tour in May, wants to be in the best shape of her life for the performances and admits she is a ''control freak.''

The 29-year-old star told Ryan Seacrest on his KIIS-FM radio show: ''I'm actually building stamina right now [for the tour.] It kicks off in May ... it goes from May 2014 until probably summer 2015 ... we are kicking it off in the UK and then we come to the U.S. all summer long.

''I'm in the middle of all the different plans and costumes and there are so many fun parts of the show. There's about five or six sections and one of my favourite sections is the ... 'Cat-ture' section [like couture] ... you know me, queen of cats ... it's so fun, visual, and vibrant.''

The brunette beauty, who is dating John Mayer, recently became the first person to amass 50 million followers on Twitter, but sometimes finds her popularity on the social networking site overwhelming.

She said: ''It's really terrifying sometimes. Can you imagine if my butt tweets itself? Or honestly to tell you the truth, I'm double checking, like don't tweet that picture.''

The singer also never expected her latest track 'Dark Horse' to be a hit.

She said: ''It's so crazy because we never planned for this to be a single and we never knew it would have this kind of attention on it. I was all up in the 'Unconditionally' world and excited to be doing a ballad and then all of a sudden the demand for this song started rising and it was literally a dark horse ... I'm such a control freak and I like to plan out everything. I was like, 'Wait, what's happening?' ''