By the age of 44, most people are happy if they've been able to avoid packing on a spare tire around the waist. Not Christy Turlington. She is back in the modeling world and is headlining the new Calvin Klein ad campaign.

"Clothes tell a story. Sometimes it's true. Sometimes it's what you want people to think," says the timeless Turlington in a new Calvin Klein video. "But this says what I really feel. It's not a secret, just personal. You might be surprised. Just between you and me."

Granted, Turlington can get her clothes to tell a better story than most. In fact, it is likely that she could turn a garbage bag into a piece of reasonably deep poetry. Having modeled for Calvin Klein ever since the 80s, her career has spanned an incredible four decades.

These latest ads were all shot in Vieques, Puerto Rico by renowned photographer Mario Sorrenti. Turlington was the centerpiece of a series of black and white ads, as well as the 30-second video clip posted above.

"It was great shooting with Mario Sorrenti. We have worked together before but never for Calvin Klein, and both of us have had a long history with this brand, so it's kind of nice to have a first-time experience with him and Calvin Klein," she said.

Since her meteoric rise to fame in the modeling industry, Turlington has involved herself in a number of different causes. She is an Advocate for Maternal Health for the international humanitarian organization CARE, as well as an ambassador for Product Red, which helps to reduce HIV/AIDS in Africa. So has her post-career philanthropy been even more rewarding than her storied modeling career?

"Gosh yes -- there's nothing rewarding about modelling," she told the Telegraph in 2010. "It was a fun opportunity that allowed me to see the world but spiritually and intellectually there is nothing rewarding about that profession at all."