New research says answering emails from bosses can affect sleep and working productivity for the next day.

Researchers from the University of Florida, Michigan State University and University of Washington conducted three studies to try to find a connection between using smartphones late in the evening and work productivity the next day. The Wall Street Journal details the studies that were done and the results. The first study consisted of 82 mid- to high-level managers. They were asked every morning how many minutes they used on their smartphones after 9 p.m. and how many hours of sleep they got that night. They were also asked to rate their agreement with the statements, "I feel drained," and "right now it would take a lot of effort for me to concentrate on anything." In the afternoon, the managers were asked to report on their productivity levels during that workday. In their second study, they monitored and interviewed 161 workers on the amount of late-night tech use, their sleep quality and levels of engagement the next day at work. The results illustrated that the use of smartphones for work-related tasks was related with less amounts of sleep, more exhaustion in the mornings and less productivity during the day. The researchers said, "the benefit of smartphone use may ... be offset by the inability of employees to fully recover from work activities while away from the office." The solution, researchers expressed, is to put the phone down in the evenings and enjoy the rest of the night. But Barnes, one of the researchers, explained that this has to start at the top. This solution can only work if managers stop sending emails late at night or have lower expectations on response times.%3Cimg%20src%3D%22http%3A//