This swimmer battled COVID-19 twice. Now, he's an Olympic gold medalist.

In the past year, British swimmer Tom Dean has battled back from COVID-19 not once, but twice. And this week, he became an Olympic gold medalist. 

"This is the single greatest achievement of my life," Dean said.  Dean first revealed his coronavirus diagnoses after qualifying for the Tokyo Games in April. He said that he was unable to exercise for weeks at a time while in isolation.