For 10 days at least, the 21st-century debate about screen time and exercise involves two items that are not mutually exclusive. Carter, a hurdler from the United States who qualified for the final on Tuesday night, acknowledged that she was among those who take full advantage of the video boards whenever practical. “I definitely use the screen,” she said.
Floréal, her coach, said that the screens are particularly useful in the preliminary rounds.
“You don’t want to go out and run too fast unless you have to,” he said Tuesday. “Obviously, looking left and right to find out where everybody is can distract you, and with the screen you are always looking ahead, so you don’t have to do that.”
But the screens also can be helpful as a real-time tool when medals are at stake.
On Friday night, the British distance star Mo Farah looked up at the display at the start of the bell lap of the 10,000-meter…