Dick Van Dyke, 99, reveals the secret to long life and what exactly keeps him young

Ahead of his landmark 100th birthday on December 13, Hollywood legend Dick Van Dyke has shared one of the secrets behind his extreme longevity and youthful exuberance.

Having spent the better part of half a century at the top of his industry, starring in 14 movies and dozens of TV shows during his charmed career, you could forgive Van Dyke for resting on his laurels during his 10th century.

But instead, he finds the energy to attend many public engagements and even write a new novel, 100 Rules for Living to 100.

In his newly published book, the 99-year-old reflects on his storied career and what his long life has taught him, with no end of anecdotes about his work on the iconic productions Dick Van Dyke Show, Chitty Chitty Bang Bang and Mary Poppins.

He also shares, in loving detail, how his wife, Arlene Silver, has given him a new lease on life.

Dick Van Dyke credits his wife, Arlene Silver, for helping him feel young (Monica Schipper/Getty Images)

“Arlene is half my age, and she makes me feel somewhere between two-thirds and three-quarters my age, which is still saying a lot,” he reveals in his new book. "Every day she finds a new way to keep me up and moving, bright and hopeful and needed."

The couple met in 2006 when the Hollywood star was a sprightly 80-year-old, at an awards show where Silver was working as a makeup artist for another celeb.

But after meeting her, Van Dyke was so smitten he broke one of his own rules, according to The New York Post.

The star 'felt drawn' to Silver when they first met and made a bold first move as Van Dyke shared in 100 Rules that he 'had never approached a strange woman before'.

In a world-class cold open, smooth-talking Van Dyke said in an email to his future wife: “Arlene, I’m afraid I was so smitten with you last night I couldn’t think of anything to say. Still, when the project at Hallmark starts, I’d like to give you a chance to talk with them. Would that be OK?”

Despite making his first-ever first move as an octogenarian, everything worked out and 'she quickly became my soulmate and love of my life'.

Arlene Silver, 54, is often seen arm in arm with her husband on the red carpet (JC Olivera/Variety via Getty Images)

The couple got married in 2012, with Van Dyke crediting her as 'the most important reason I have not withered away into a hermetic grouch' as she has quite an active role in his day-to-day life.

"Arlene is my partner in love, life, and logistics. She has two phones and is often on both, scheduling and juggling more gigs and get-togethers than you could possibly imagine," the actor said.

“Arlene knows how much performing and being social nourishes my spirit and brings me alive. I would absolutely be origami guy if she didn’t have me singing and dancing.”

While the 99-year-old says his younger wife is a source of his longevity, he has previously attributed his long life to something everyone can get on board with - regular exercise.

"Three days a week, we go to the gym, still. Three days a week," he said on the Everybody Knows Your Name podcast earlier this year.