That's one of the findings of the just-released report from the Women's Sports Foundation report Teen Sport in America: Why Participation Matters. In this case, focus means playing just a single sport. Playing one sport versus multiple sports was one of the questions that the Women's Sports Foundation (WSF) report addressed. You may think that those who played multiple sports got less sleep because they are busier. Of note, the WSF analysis found that all of these numbers were better for those who played one sport versus those who played no sports.

Source: Forbes January 28, 2018 18:00 UTC