Body of Work: The Top 20 Fitness Icons

The Gold Standard: Jackie Joyner-Kersee

Track-and-field icon Jackie Joyner-Kersee gets bored on the treadmill, just like the rest of us. "I have to mix it up: I adjust the incline or the speed, run a minute, walk a minute -- anything to make the time go faster," she admits.

Joyner-Kersee's graciousness and lack of pretension are arguably as famous as her achievements. Named the greatest female athlete of the 20th century by Sports Illustrated for Women, she has held the world record for the heptathlon -- 100-meter hurdles, high jump, long jump, shot put, javelin, and 200-meter and 400-meter runs -- for 24 years; in sports, that's an eternity. A four-time world champion, Joyner-Kersee's trove of six Olympic medals, won from 1988 to 1996, includes three golds, one silver, and two bronzes.

Winning that first gold medal in the heptathlon at the 1988 games in Seoul "is still and always will be a thrill," she says. For us, too. For 16 years, fans of the Summer Olympics watched her run, jump, and throw with an explosiveness and joy that remains unrivaled. These days, at 50, her life revolves around public speaking and doing community work in her hometown of East Saint Louis, Illinois, where she mentors a high school girls' track team. "I don't approach my speaking and coaching engagements as if I'm some superstar," Joyner-Kersee says. "I want to inspire and motivate and have people appreciate my hard work."