Lyons earned a gold medal as a member of the first-place U.S. team in the men's 4×200-meter freestyle relay at the 1963 Pan American Games.

At the 1964 Summer Olympics in Tokyo, he swam for the gold medal-winning U.S. team in the preliminary heats of the men's 4×200-meter freestyle relay.

[1] Under the 1964 Olympic rules he was ineligible to receive a medal, however, because he did swim in the event final.

Lyons began his competitive swimming at New Trier High School, Winnetka, Illinois.

He won three consecutive NCAA national championships as a member of winning Yale teams in the 400-yard freestyle relay.