If Noah Lyles had COVID, why was he allowed to compete in Paris?

(NEXSTAR) – After Noah Lyles competed in the 200-meter final in Paris Thursday, he collapsed to the ground – and it wasn't just from exhaustion. The American sprinter had been diagnosed with COVID-19 two days prior at the Olympics, Lyles told reporters after the race wrapped.

If Lyles knew he had COVID before the race even started, why was he allowed to compete?

According to Scientific American, athletes who test positive for the virus are still allowed to participate in the competition – and several have.