RIO DE JANEIRO — Nathan Adrian was sitting on a stool on a rooftop across from Copacabana Beach, watching as the marathon swimmers flailed their way through the open ocean. He talked about “feeders,” the people who give the swimmers packets of energy liquid during the swim. He pointed out the swimmer who was well ahead of the pack, and said, “She’s going to have to work a lot harder than everybody else. They’re all drafting off each other. I don’t know if that will work.”
Adrian is not a marathoner, of course. But the guy knows swimming.