A few years ago, scientists conducted a real-world experiment at a ThyssenKrupp steel factory in Germany. They assigned the day shift to early risers and the late shift to night owls.
Soon the steel workers, many of whom had been skeptical at the outset, were getting an extra hour of sleep on work nights. By simply aligning work schedules with people’s internal clocks, the researchers had helped people get more and better rest.
“They got 16 percent more sleep, almost a full night’s length over the course of the week,” said Till Roenneberg, a chronobiologist at Ludwig-Maximilian University in Munich, who headed the study. “That is enormous.”
In recent years, American educators have been paying increased attention to their students’ sleep needs, with growing debate about delaying school start times. Now a number of businesses are following suit, encouraging their employees to work when their bodies are most awake.