Why do many Americans suffer from burnout, reduced productivity, diminished creativity, failed relationships, stress, depression, heart disease and stomach ulcers? The answer may be as simple as a failure to rest and relax.

America's puritanical work ethic emphasizes effort and extra hours, but overscheduling can destroy creativity, not to mention mental and physical health. Consider Denmark, the world's happiest country, according to independent studies from the University of Leicester and the University of Michigan. Danish workers receive 31 days of paid vacation each year -- the most in the world.

American workers, on average, only accumulate 10 paid vacation days per year, which many employees skip. According to a Harris Interactive research group, Americans failed to take 438 million paid vacation days in 2007.

Working nonstop doesn't make workers more productive. Instead, it hurts effectiveness. Relaxation clears frenetic energy from minds and bodies, dramatically improving mood and attitude. Taking time off helps workers regain their bearings, so that, when they return to work, they feel more focused and productive.

Darren Hardy, publisher and editorial director of SUCCESS Magazine, offers these tips to Americans who need to recharge their batteries:

* Rephrase "time off." If you can't handle the idea of taking time off, call your down time something else. Hardy calls his time off "Rejuvenation Time," which sounds purposeful, productive and worthwhile.

* Schedule time for yourself. Mark vacation time on your calendar, then treat it like an unmoveable appointment with Oprah or the Queen of England. When you do take time off, turn off your e-mail and Blackberries.

* Declare when you're going on vacation. Tell everyone what your doing and that you won't be available.

* Measure your time off. Measure the number of times you eat dinner with you family, take naps, meditate, read for pleasure, watch movies and engage in activities that you enjoy. If you only have fun every once in awhile, concentrate on building more time for yourself into your busy schedule.