One in five workers is sleep deprived, and those who sleep poorly are 54% more likely to experience stress in their job, according to a new GCC Insights study. The study was compiled by international employee health and performance organization Global Corporate Challenge (GCC).

The report also found that 93% of poor sleepers were more likely to display workplace fatigue, a common symptom of excessive daytime sleepiness (EDS), a condition that increases risks of absenteeism, accidents, and injury in the workplace.

The results come from the health and performance leaders’ first series of GCC Insights papers, based on aggregate data drawn from employees in 185 countries. More than 1.5 million people have now been through GCC’s program.

Dr David Batman, director of research, FCDP, says in a release: “Independent research undertaken on GCC participants in the 2014 challenge demonstrates that sleep improves with increase step count in a linear fashion. There are significant increases in productivity and reduction in fatigue and stress levels at work and home. Extrapolation of these results leads to an obvious conclusion that simple exercise improves sleep, and the combined result will be an increase in personal and business performance.”

While the rest and recuperation required over the festive period is, in reality, often negated by overindulgence and family demands, the expectation is that employees return to work in January feeling recharged and ready to perform their best.

This GCC Insights paper also provides practical recommendations for employers who recognize that their people’s mental and physical health is inextricably linked to business success—a realization that, for many, signals a need to rethink outdated, “tick-box” well-being strategies in exchange for a longer term commitment to employee health.

Glenn Riseley, GCC founder and president, says, “The cost of poor sleep habits amongst employee populations has been grossly underestimated; it is having profound consequences for productivity and health. Luckily, enlightened employers are now changing their cultures so that sleep is no longer seen as a luxury but as a priority.”