Donna Mills does 100 sit-ups a day, plays tennis five times a week at 85 but won't quit Doritos

Donna Mills is keeping fans on their toes at 85, from launching an OnlyFans account to revealing the intense fitness routine she credits with keeping her active.

The former ballerina, best known for playing the scheming Abby Cunningham on "Knots Landing," revealed to Fox News Digital the demanding fitness routine she credits with keeping her moving — including 100 sit-ups, 50 leg lifts, up to an hour on the bike and, sometimes, tennis five days a week.

And while Mills has long been disciplined about her health — including cutting out sugar — there is one indulgence she refuses to completely give up.

"Im a Doritos addict," Mills confessed.

The actress revealed that nacho cheese is her flavor of choice, showing that even her disciplined wellness routine leaves room for a guilty pleasure.

"I mean, its not good for you. Its not. You know, I know I shouldnt do it," Mills admitted.

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Still, she said the popular snack has followed her throughout her decades-long career.

"Different sets that Ive been on… for some reason, they know — they always got a bag of Doritos in the trailer for me… its really funny. But Ive never lost that. I dont eat them as much as I used to. But theyre still a treat."

When it comes to exercise, Mills' routine is considerably more demanding.

"I started out as a dancer, so a ballerina. I mean, I was on pointe, the whole thing," she said.

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Mills said her early training instilled a work ethic that has stuck with her throughout her life.

"So that gave me a discipline that most people dont have because ballet is very hard," she explained.

To this day, she still incorporates elements of her early training into her workouts.

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"I do 100 sit-ups a day, 50 leg lifts, lots of stretching. I have a ballet barre in my little gym."

Her rigorous routine doesnt stop there.

"And ride the bike for about 45 minutes or an hour," she continued.

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She also stays active on the court whenever she can.

"I play tennis five times a week sometimes. And so thats very, very important."

The Hollywood actress takes a similarly disciplined approach to her diet, saying a book she read years ago influenced her decision to cut back on sweets.

"Ive always been anti-sugar," she said. "I read a book a long time ago called 'Sugar Blues' that really talked about the sugar industry and everything, and I have stayed away from it ever since."

Still, Mills isn't pretending her lifestyle is effortless.

"Its a lot of stuff. You got to work at it."

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Her fitness routine comes as Mills enters what she describes as an entirely new chapter of her life.

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