On July 15, 1980, at the Canadian Olympic trials, Szmidt set the world record for 400-meter freestyle with a time of 3:50:49. He held the world record at the time of the 1980 Olympics, in which he did not race due to the boycott. The world record stood for 18 months and was a Canadian record for 20 years.
Szmidt swam in competition with Russian swimmer Vladimir Salnikov, who dominated long-distance freestyle swimming in the late 1970s and early 1980s. Szmidt's 400-metre record was the only interruption in Salnikov's title as the world record-holder for 400-meter freestyle from 1979 through 1985.