Katherine Hamilton during a 1981 hurdles race when she was a sophomore at Berkeley. Later that year, Hamilton quit the team and walked away from her sport, largely because of the prevalence of performance-enhancing drugs at the top levels of track and field. Courtesy of Martha Edwards hide caption

itoggle caption Courtesy of Martha Edwards

LeBron James announces his decision during a primetime special hosted by ESPN's Jim Gray on Thursday night at the Boys & Girls Club of America in Greenwich, Conn. Larry Busacca/Getty Images hide caption

itoggle caption Larry Busacca/Getty Images

The Los Angeles Lakers celebrate winning the NBA championship, 83-79, over the Boston Celtics on Thursday at Staples Center in Los Angeles. Chris Pizzello/AP hide caption

itoggle caption Chris Pizzello/AP