It's old news that employees' physical and mental health and wellness has a direct impact on their productivity at work. But the extent of that impact—revealed in a new study by Vitality Group, Cambridge University, and Charles University researchers—is far more dramatic than we realized.

After analyzing more than 30,000 employees across 173 organizations through Vitality's annual Britain's Healthiest Workplace survey, the researchers found that mental and physical health account for more than 84 percent of the direct effects on productivity loss. Plus, they discovered that 93 percent of the indirect influences are mediated through mental and/or physical health. In other words, "even job or workplace factors, such as job satisfaction, support from managers or feeling isolated ultimately affect productivity through mental and/or physical health," as Vitality reports in a press release.

"At first glance, the results may not be surprising as we've known for some time that the way companies operate has a direct impact on employee health, but also that employee health directly impacts the success of companies," says Francois Millard, SVP and Chief Actuarial Officer at Vitality Group. "What's concerning is that despite these identified issues, organizations continue to spend billions of dollars on addressing the symptoms related to physical and mental health rather than the causes."

Werk expressed similar concerns in our research paper, pointing out that the corporate health and wellness programs offered by the $8 billion workplace wellness industry often "aim to address poor health and wellness by adding incentives for being well rather than removing the barriers to being well."

And this is where workplace flexibility can play a game-changing role. Time-based modifications to the workday including MicroAgility and TimeShift empower employees to exercise or to attend medical appointments or mental health counseling sessions—at a time when current workday structures make it difficult for 29 percent of U.S. workers to manage a physical condition or chronic illness, for 30 percent to be available for recurring health appointments, and for 36 percent to make time for exercise and healthy living, according to our research.

Plus, the current workday structure makes it difficult for 30 percent of workers to get enough sleep at night, and a 2009 study found that sleep deprivation costs the U.S. economy an estimated $411 billion every year. The structure the workplace flexibility Werk promotes helps to establish clear boundaries so that employees with flexibility aren't "always on" and can actually have a shot at getting a restful eight hours of sleep each night.

And flexibility can be a literal lifesaver during disease outbreaks or even inclement weather, allowing employees to work from home or at a location closer to home when they're sick or when their commute would be hazardous to their health.

Flex doesn't just max out productivity through employee health and wellness, however. Learn much more about flexibility's productivity boosts here.