As a One Direction heartthrob, he sang about being Up All Night.
But these days Harry Styles sleeps for 10 hours a day and has ditched booze to focus on his music.
The 28-year-old said: “Drinking dehydrates my voice. It would be really freeing if I could have a night out and then do a show the next day, but I just can’t.
“I did it once… it was my least favourite show ever. I felt like it was so bad.
“You owe it to who is coming. Even if it is our 40th show, it is most people’s first show.
“It kind of feels like if that is the sacrifice I have to make, then I am OK with it.”
Harry also revealed he needs a “minimum of 10 to 11 hours” of sleep a day while touring, and approaches his shows as if he is running a marathon.
He said: “It’s a pretty incredible thing I get to do and I love it so much, so to treat it as such doesn’t feel like a sacrifice.
“For those two or so hours a night, I want to be at 100% and give it everything.
“If that means for the rest of the time I’m resting and taking care of my body, then that is what it is.
"It doesn’t feel like I am giving up on life. If anything, I enjoy going into that meditative state on tour.”
Harry, who is dating US actress and director Olivia Wilde, 38, will soon be seen on our TV screens as a gay cop in Amazon romantic drama, My Policeman.
And after upping his therapy sessions, the star says he is in a “pretty good place” right now.
Harry said: “Therapy changed my life a big way. My therapist is based in LA and I live in London.
“I don’t think it is a magic pill thing where you start going to therapy and everything is fine. You have to do some work.
“I block off time for exercising because I know I need to do that to make me feel good.
“I started thinking, ‘Why wouldn’t I do that for my mind?’ Therapy is something I’d strongly recommend.”
