Nearly three quarters of American workers report feeling stressed at work. Twenty-five percent of these workers are either “very” or “extremely” stressed. All work and no play can lead to health and heart issues, mental decline, increased cortisol production, burnout, and even depression. In fact, if people skip vacations, there’s a chance that they may die younger than those who don’t.

As Americans, we’re obsessed with work. We’re using less vacation time today compared to any point in the last 40 years, according a new study by Achor and the U.S. Travel Association’s Project: Time Off initiative. The average U.S. employee only takes half (51%) of their eligible paid time off, and when we do take time off, we’re not completely unplugging – three in five (61%) of us still check email.

The leading reason for not taking PTO is known as the “martyr complex,” believing no one else in the company can perform an employee’s work (33%). Next is the fear of getting behind and returning to a backlog, thus increasing stress in the long run and distracting from vacation R&R. Following is wanting a promotion or pay raise, and fear of being replaced or losing a job. Finally, some employees are just plain afraid of boss or company attitude toward vacation. Seen as a weakness, not taking vacation is often worn as a badge of honor and many employees report feeling guilty for actually using earned time off.

“The ill effects of refusing to go on vacation, documented in research, include fatigue, poor morale, heart problems, and reduced productivity,” reports Sue Shellenbarger in a Wall Street Journal article.

Furthermore, as told to ABC News, clinical psychologist Deborah Mulhern has found that people who don’t take enough time to relax may find it harder to relax in the future:

“Without time and opportunity to [relax], the neural connections that produce feelings of calm and peacefulness become weaker, making it actually more difficult to shift into less-stressed modes. What neuroscience is showing is that we require down time in order for our bodies to go through the process of restoration. It is only when we are safe from external stresses that our bodies can relax enough to activate restoration.”

By taking vacation, employees make valuable strides towards counteracting these negative health and mental effects. But the benefits are not limited to the employee alone. The same Project: Time Off study found that employees who take a vacation are actually more likely to get promoted and get a raise, meaning vacations can actually be beneficial for the company’s bottom line.

In the idealist world of trendy tech, investor-backed start-ups, some companies pay employees more for taking time off. But for a small business with limited staff, funds, and resources – and where you, the business owner is usually just as overworked as everyone else – this approach is not realistic. However, there are still ways to encourage, even enforce, annual vacation.

At HubSpot, for example, salespeople are allowed to reduce their quotas twice a year, Shellenbarger reports, helping them to feel more comfortable about using paid vacation time without impacting their workload, performance review, or compensation. Other companies enforce vacation through raffle in which all employees are entered once for every year at the company and chosen at random. There are no exceptions and employees report increased communication as other team members must pick up projects outside their initial work scope when someone is “forced” on vacation. You may consider adapting similar practices at your company, if the right fit.

Also remind your employees that a “vacation” doesn’t have to be a two-week overseas traipse across Europe (although that’s probably the dream!). Vacations can be a short trip to a local destination or even spending time with family at home. Regardless of the activity, the point is to give your body and brain a much-needed rest from our information-driven world and the stressors that typically come with work.

Finally, as a last resort for the most stubborn workforce, build vacation days or company holidays into the company calendar. On these days – and all other vacation days – enforce a strict no work-from-home policy – no checking email, making sales calls, monitoring social media, or otherwise contacting or working on behalf of the company for any reason outside of urgent, time-sensitive matters approved prior to time off, such as engineering issues that effect the website.

Even if you already agree that your employees need vacation time, you must be communicating this idea effectively. Create a vacation policy for employees to refer to in writing. Speak with your managers to ensure there are no mixed or negative messages regarding requested vacation time, as long as they are in line with the policy. And finally, lead by example! Take vacation yourself! It may not be realistic for you to spend two weeks in Europe either, but you can make time away from the office to reap all of the same benefits important for your team.

“If we can train ourselves to take regular vacations – true vacations without work – and to set aside time for naps and contemplation, we will be in a more powerful position to start solving some of the world’s big problems,” claims Daniel J. Levitin, Director of the Laboratory for Music, Cognition and Expertise at McGill University.

Vacations make better problem-solvers, more creative thinkers, and happier, more productive humans both at and away from work. Bosses return as more focused, effective leaders. And your workers will bring their new experiences back to the office, enriching their output.

As we approach this holiday season and a New Year, how will you encourage vacation time in your company?