More than eight in 10 Americans are stressed about their jobs, and yet we're not taking the time we need to de-stress. Eighty-one percent of employed Americans check their work email on weekends and 55 percent visit their inboxes after 11 p.m., according to an Opinion Matters survey, and one-third say that they respond to emails at work within 15 minutes.

Most of us, most of the time, live in a gray zone of sorts between work and leisure. We're not fully focused when we're working -- with smartphones, email alerts and social media constantly vying for our attention -- and when we're "relaxing" on the weekend, we're still plugged in to work. But being smart about how you spend your weekends could make you happier and more productive.

"There are 60 hours between that 6 p.m. Friday beer and that 6 a.m. Monday alarm clock," "168 Hours" author Laura Vanderkam writes in a Fast Company blog. "That’s plenty of time for fun, relaxation and more importantly, recharging the batteries. In our competitive world, successful people know that great weekends are the secret to workday success. You want weekends that leave you refreshed, not exhausted or disappointed."

Of course, it's preferable to use the full weekend for relaxing and recharging. But if your job does require that you get some work done during your time off, here's the right way to go about it.

Turbo-charge one hour of work.
It can be easy to graze on work email throughout the weekend, especially when you're getting messages from your boss -- which most employees are. Close to two-thirds of workers say their bosses send email over the weekend and expect a response, according to a 2011 Right Management survey, as reported by Forbes.

Interface Inc. CEO Daniel Hendrix told the New York Times that he had been working 24/7 when his then-boss sparked an epiphany about overworking on the weekends.

"The company brought in a president above me who was really charismatic and dynamic," Hendrix said to the Times. "One day he was in the office on a Sunday and he said: 'Every time I’m in here on Sunday, you’re in here working. I’m not impressed by somebody who can’t get their job done in five days. I’m really not. It’s about balance.'"

When we don't relax on the weekends, we have a hard time recovering from the stress of the workweek. The solution? Rather than sending emails here and there throughout your 72 hours off, set aside one hour on Saturday or Sunday to get it all done -- and save the rest of the weekend for relaxing. Stick to the schedule and resist the urge to take a peek at your inbox outside that hour.

Be intentional with your energy.
According to Tony Schwartz, CEO of The Energy Project and author of "The Way We're Working Isn't Working," applying a “fierce intentionality” to all that we do can benefit both our work and personal lives.

"That means that when you're working, you're really working; and when you're renewing and refueling, you're really renewing," Schwartz said at HuffPost's Third Metric conference in June.

Save it for Sunday night.
Many successful CEOs and business leaders say that they do this by setting aside one specific hour or chunk of time for work, and unplugging for the rest of the weekend. Often it's Sunday night -- so that you can start work on Monday morning feeling caught up -- but any quiet pocket of time will do the trick.

“I save everything up until Sunday night,” SurveyMonkey CEO Dave Goldberg told Business Insider in May, “because if I start sending emails on Saturday afternoon, then people have to start responding to me on Saturday afternoon and Sunday morning.”

Disable your phone's email function.
If your job allows, disabling the email function on your smartphone can ensure that you apply intentionality to your weekend work, only sending emails during the allotted time when you're home and in front of your computer. When you have emails constantly popping up on your phone, it's likely that you'll be tempted to answer them.