Ruben Mata, a fitness trainer in Stanton, California, who has traveled the world as a motivational speaker, was adamant in the early days of the epidemic that the coronavirus was not real. Most of what he had heard about the virus he’d gleaned from his friends at the gym he attended religiously, even as the pandemic raged across the U.S. But just a couple of weeks after the Trump administration declared a national emergency on March , Mata, 53, was diagnosed with COVID-19. He subsequently spent five days in a medically induced coma; at one point he was given less than a 40 percent chance of survival. Now he wants others to learn from his missteps.