While the Swimsuit Issue began as a five-page insert to the magazine, by 1997 it had become a stand-alone issue that has raked in more than $1 billion to date. According to Forbes, it remains the most profitable single edition of any magazine in the world.
While the pages of the SI Swimsuit Issue have featured many well-known models, including Cheryl Tiegs, Tyra Banks, Heidi Klum, Christie Brinkley and Kate Upton, the best-selling issue of all time is 1989's 25th anniversary edition featuring Kathy Ireland on the cover.
In this behind-the-scenes video, Ireland reveals some of her secrets to working under tough conditions as they shoot the swimsuit edition:
Ireland was featured in a whopping 13 consecutive years of the Sports Illustrated Swimsuit Issues, including three covers – one when she was pregnant. While her record is certainly impressive, her accomplishments since leaving the modeling world are even more inspiring.
In addition to being a mother of three, Ireland, 50, has built a mega-business out of her personal brand. After giving Hollywood a whirl, finding roles in dozens of television shows and films, the supermodel found ultimate success in the boardroom.
As the CEO of Kathy Ireland Worldwide, she is giving domestic goddess Martha Stewart a run for her money. Ireland has created a $2 billion design empire of licensed products, based on her company's motto of "finding solutions for families, especially busy moms." She has subsequently earned the title of Richest Supermodel in the World.
The super-mogul is also a self-help maven, producing bestselling workout videos and penning motivational titles such as Powerful Inspirations: Eight Lessons that Will Change Your Life, inspired in part by her own weight-loss battles. Additionally, Ireland runs a mentoring program for single teen mothers.
The former swimsuit cover girl is now turning her eye towards conquering the pet world. Ireland recently teamed up with Worldwise, an eco-friendly pet product company, to create a new line of products called Kathy Ireland Loved Ones.
To sum it up, Ireland is living proof that one should never underestimate a person just because she looks great in a yellow bikini.
NBC and Time Inc. have partnered to present a two-hour TV special celebrating the 50th anniversary of Sports Illustrated's swimsuit franchise – one of the most hotly-anticipated annual fixtures in American pop culture. "Sports Illustrated Swimsuit: 50 Years of Beautiful" is set to air on NBC, Monday, Feb. 3 at 9 p.m. ET/PT.