Fit Sharon Stone proves stroll around Sainsbury's won't give you thighs of steel

We had a fire drill at work on Tuesday which meant ­walking down 22 flights of stairs.

By the time I got to the bottom my legs were shaking so much I thought I was ­going to fall over.

And when I got home that evening I did.

I dropped my keys, squatted down to get them, couldn’t stand up again and toppled over.

No one saw me, thank God, but I was mortified.

I am a 55-year-old woman with 85-year-old legs – because I spend eight hours a day sitting on my bum staring at a computer screen.

And it’s finally dawned on me that a weekend stroll round Sainsbury’s is not going to give me thighs of steel.

Sharon Stone's shapely pins have been iconic since 1992's Basic Instinct (Emma Summerton for Allure)

I need to take a stand against my sedentary lifestyle and get the old pins back in shape.

And what better inspiration could there be than gorgeous 61-year-old Sharon Stone.

She’s been flashing her long lallies in a magazine article about beauty and anti-ageing.

Sharon nearly died from a stroke when she was in her 40s and only then started focusing on her health. Now she feels and looks better than ever. She has barely changed since that iconic leg-uncrossing scene in 1992 thriller Basic Instinct.

Although she did remember to put her knickers on this time.

Unfit types like me could also be inspired by standing-up GP appointments now ­being trialled by doctors in the Midlands, where patients will only be told to take a seat if they look in real need.

“Doctors often neglect their own health,” said the medic leading the pilot.

Sharon Stone features on the cover of Allure magazine and shares her new healthier outlook on life in an interview (Emma Summerton for Allure)

“We need to find ways of getting GPs on their feet and moving more often. Standing consultations could help them and highlight to patients the importance of reduced sitting time.”

GPs can also send their patients to dance classes and sports clubs too, thanks to a £5million scheme designed to cut drugs prescribing.

And I’ve decided to take up ballet.

Because I recently met TV star Angela Rippon, 75, who’s Ambassador of Silver Swans – Royal Ballet-run classes for over-50s.

She told me a friend of 85 had recently started going and is already so strong on her pins “she can put her knickers on ­without having to sit down”.

A conversation I recalled with a grimace as I was getting dressed on Wednesday morning.