Michael Jordan
Before he was the Greatest of All Time, he was an Olympian. Michael Jordan entered his first Olympics straight out of college in 1984. He helped Team USA take home the gold in 1984 and 1992. He was welcomed into the NBA with open arms and won six championships with the Chicago Bulls. He retired in 2003, but he's been quite busy! He has an incredibly successful sports apparel line and received the title of a billionaire in 2015.
Rhonda Rousey
Rhonda Rousey is known for a lot of things, but she went to the Olympics for Judo. She was only 17 when she entered the 2004 Olympics (following in her mother's judo footsteps!) She earned a bronze medal in the 2008 Olympics. She started her MMA career in 2011 and became a household name due to her flawless fighting and 12-match winning streak. She retired from UFC and entered a career in the WWE.