Bette Midler has revealed she doesn’t care what size she is – she just works out to keep her voice in shape.

The 69-year-old singing and acting legend is to play a string of gigs across the UK next year, her first here since 1980, and she admits her voice is a well-oiled machine.

Bette said: “There are certain parts of my voice that sound very young. I never smoked like a real fiend, so I didn’t lose the top end of my voice. You can keep your high voice, but you have to look after yourself.

A portrait shot of Bette Midler
Bette Midler treats her voice like a machine (Dan Hallman/Invision/Press Association Images)

“I run on the treadmill. And it’s only for the pumps – I don’t care whether I’m thin or fat, but I care about whether the lungs are working to drive the voice. It’s like a car, you have to take care of it, clean those spark plugs, baby!”

The Beaches star completed a two-year stint of nightly live performances in Las Vegas in 2010, a time she looks back on as “the most beautiful show I ever did. That means a lot to me”.

But she admitted it was a gruelling schedule.

“It was hard work,” she revealed. “I had a little adrenal failure, where you just can’t get up every night. I was having a lot of Vitamin B12 shots to get through it.”

This latest string of shows is rumoured to be Bette’s farewell tour.

“I don’t know. Possibly,” she admitted. “I don’t know how wise it is to go on forever. If the spirit is willing and the flesh is strong, then go for it, but if something is holding you back, you shouldn’t be chained to the idea that you can’t retire.

“There are people who come alive when they think about the possibilities of travelling in their retirement.”