Nathan attended the University of California, Berkeley where he majored in public health. While in college he was a five-time NCAA individual champion. Nathan participated in the 2008 Olympics in Beijing as a member of the 4×100-meter freestyle relay. At the 2016 Rio games, Nathan won a gold medal in the Men’s 4x100m medley relay, a gold in the men’s 4x100m freestyle relay, a bronze in the men’s 50m freestyle and a bronze in the men’s 100m freestyle.