Professional boxer and entrepreneur George Foreman is a legend both in and out of the ring. After winning Olympic gold in 1968, he turned professional, winning the World Heavyweight title in 1973. More than 20 years later, in 1994, he regained that title, becoming the oldest champion in boxing history and simultaneously introducing the George Foreman Grill. He sold the company five years later for $138 million. Since its introduction, more than 100 million George Foreman Grills have been sold globally.

Like many Olympic athletes, Foreman turned the dedication and perseverance that helped make him a champion toward business, transforming himself into a successful entrepreneur. There is no ideal time to launch entrepreneurial dreams. Foreman launched after a long professional career. A few begin their entrepreneurial careers early, to help finance their athletic careers. More often, however, business success comes years after athletes have retired from competitive sports.

Here’s a look at five successful Olympic entrepreneurs:

Ibtihaj Muhammad

Olympic newcomer Ibtihaj Muhammad, competing in women’s sabre fencing in the 2016 Rio Olympic games, will be the first American to compete in the Olympics wearing hijab. Unable to find modest clothing she liked, Muhammad formed Louella by Ibtihaj Muhammad, which designs, manufactures and sells fashionable, conservative clothing at affordable prices.

Dick and Judy Geer Dreissingacker

Rower turned engineer, Dick Dreissingacker, didn’t medal in the 1972 Munich Olympic games, but he, his brother and three-time Olympian wife Judy Geer (who competed in 1976 and 1984, and was a member of the 1980s team that boycotted the Soviet Olympics), used their experience to revolutionize the carbon fiber oars used by rowing crews everywhere. Concept2’s stronger, lighter oars were used by about two-thirds of the rowing teams at the 2012 Beijing Olympics.

Benjamin Lewis

Serial entrepreneur Benjamin Lewis, captain of the 2004 Athens Olympic sprint kayak team and a veterinarian, has several companies under his belt. He founded Ethical Animal Research to pay for medical treatments for the sickest of animals and The One Health Company to revolutionize animal testing. His previous startup, 4Vets, launched in Brazil, is now a $20 million company.

Sam Mikulak

Gymnast, Sam Mikulak, finished fifth in the team event at the 2015 London Olympic games and is considered the one to watch in the 2016 Olympic trials. MateBros, the company he Kickstarted with two friends in 2014, developed a South American energy tea for North American tastes using yerba mate, a tea leaf that helps combat chronic fatigue syndrome.

Carrie Englert Zimmerman

After placing sixth in the team event in the 1976 Montreal Olympics, gymnast Carrie Englert Zimmerman and her husband founded The Zimmerman Agency, a Florida advertising and public relations firm that is ranked 30th in the nation. Net annual revenues exceed $13.3 million.

These athletes knew their competitive careers were limited to a few years and planned ahead. They developed broad interests and expertise and developed them into thriving companies. And that is the heart of entrepreneurism – focused individuals, accepting risk, to make their dreams reality.