If you didn’t use all your vacation days last year, you’re not alone.

Many of us leave an abundance of vacation time on the table. In fact, in 2018, Americans left 768 million vacation days unused.

And even if we do take some time off, we may still have that nagging feeling of needing to send one last email. But you might want to reconsider that mindset — especially if you want your time off to count.

A recent study from the University of Georgia suggests that vacations offer more benefits than we once thought, and that those benefits last long after you reach your destination.

The paper, which analyzed 32 studies across nine countries, found that employees who psychologically disengaged from work during their time off experienced the most significant boost to their well-being. That means no emails, no Zoom calls, and, ideally, next to no thoughts about the office — yes, even if you work from home.

In this case, the research holds true: Vacations are one of the few opportunities we must truly disconnect from the day-to-day grind.

Engaging in physical activities on vacation, like hiking or snorkeling, further boosts your well-earned well-being. But don’t worry about pumping iron or running a 10K — anything that gets your heart rate up counts.

One caveat: Longer vacations seem to offer more benefits but can also lead to a sharper decline in wellness once you’re back to work. That’s why planning and giving yourself a day or two to ease back into the work routine can help you transition more smoothly and maximize the benefits of your time off.

So, next time, make it count — and leave your to-do list for work behind.