Katy Perry's ''knees are giving out'' after years of performing.

The 'Dark Horse' hitmaker, who performed more than 100 shows in seven months last year, also claims her body can no longer handle a lot of alcohol now that she is 30.

She said: ''My knees are giving out on me now. I do acupuncture every two to three days. I tour with a sage that goes from the front of the house to the back of the house with a triangle thrust that is a moving treadmill, [like] I think I'm some kind of Olympic athlete! I don't drink much. I used to drink a lot more when I was younger. Body can't take it. Mind can't take it. Focus can't take it. You know how it is - 30, you just don't recover.''

Meanwhile, the 'Roar' hitmaker, who is filming a sequel to the documentary 'Part of Me,' claims the NFL banned her from allowing Snoop Dogg to participate in her Super Bowl half-time show despite collaborating with him on her hit 'California Gurls' after he called Iggy Azalea ''a ****'' in a video he posted on Instagram.

She told US Elle magazine's March issue: ''And you wanna know why? Because of the Iggy Azalea thing. Not that that was it - that was just the tipping point. You can't have that kind of hate at the Super Bowl. They already have enough female-hate problems, they don't need any more.''