Ran the Romanian women's gymnastics program from the late 1960s through the 1970s. In 1976, was the coach for Nadia Comaneci, who scored the first perfect 10 in Olympic gymnastics on the way to the all-around gold medal. After disagreements with Romanian officials, he and his wife defected to the U.S. in 1981. Became partners in a gym in Houston, which he eventually bought and turned into a gymnastics camp. At the 1984 Olympics, was the coach of all-round gold medalist Mary Lou Retton and uneven bars gold medalist Julianne McNamara. Was named women's head coach at the '88 Games, after a bill passed through Congress to make him a U.S. citizen prior to a five-year residency requirement. Coached the '92 team, and the '96 team that won the gold medal and was known as "The Magnificent Seven." Carried Kerri Strug to the podium after her gold-medal-winning vault. Was inducted into the International Gymnastics Hall of Fame in 1997. Retired from coaching, he was named National Team Coordinator in 2000, a title later give to his wife Marta in 2001. Served as a guest commentator for gymnastics in NBC 2008 Olympic coverage.