NATIONWIDE -- Friday is World Sleep Day and as part of the global initiative, doctors around the world are reminding people that a good night's sleep is as important to your health as what you eat.

Experts say there's no set number of hours that quantify a good night's sleep, but for most people it's between 7 and 9 hours.  Failing to get enough sleep can lead to drowsiness and behavioral issues in the short-term, but in the long-term, developing sleep apnea can pose serious risks to your health. And if you're one of those people who likes to take a nice long nap to catch up on your Zs, well, you may actually be doing more harm than good.

"What happens during the night affects the day, and what happens during the day affects the night.  If you sleep excessively during the day you may be stealing sleep from the following night," said Dr. Antonio Culebras, Co-Chair of World Sleep Day and Professor of Neurology at Upstate Medical University in Syracuse.

Culebras say naps for adults should only be 45 minutes to an hour long.  He also suggests a few tips for what NOT to do before bed, if you want a good night's sleep:

What NOT to do Right Before Bed

  • Exercise
  • Eat a large meal
  • Smoke
  • Drink caffeine
  • Drink Alcohol in excess
For more information about World Sleep Day, visit their website.