A three-time Olympian, he won a silver medal at the 2008 Olympic Games in Beijing in team sabre.

[8] He later received his MBA from Columbia University in 2010, and now works as a Senior Vice President for Chelsea Piers Fitness which he had joined in 2017.

[1][10] In the saber team semi-finals the United States had been losing to Russia 40–35, before Smart outscored Russian Stanislav Pozdnyakov 10–4 for the win, with Team USA beating the Russians 45–44, allowing the Americans to go on to win the silver medal.

[1] His sister Erinn also earned a silver medal as part of the US women's foil team at the 2008 Olympics.

Keeth and his sister Erinn are actively involved in the Peter Westbrook Foundation in New York City.