Career
Knysh made his official debut for the 2004 Summer Olympics in Athens, where he placed sixth for the national sprint team in the preliminary heats of men"s 4 × 400 m relay, with a time of 3:04.01. At the 2008 Summer Olympics in Beijing, Knysh competed for the men"s 400 metres this time, as an individual athlete. He finished the race in sixth place by one quarter of a second (025) behind Russia"s Maksim Dyldin, with a time of 46.28 seconds.
Knysh, however, failed to advance into the semi-finals, as he placed thirty-sixth overall and was ranked below three mandatory slots for the next round.
He also tied his overall position in the heats with Dominican Republic"s Arismendy Peguero.