Sleep Debt

It takes more than a weekend to catch up on lost zzz’s. Tack an extra hour or two onto your sleep time until your sleep debt is repaid.
If you burn the midnight oil during the week, you can’t catch up on all of your lost sleep by sleeping in on the weekend. Your body needs to recoup every hour of missed shut-eye. So if you deprive yourself of two hours of sleep Monday through Thursday to meet a major deadline, that’s eight extra hours of bedtime that you have to make up in order for your body to recover.
People who routinely get fewer than six hours of sleep per night may be unwittingly racking up this so-called sleep debt, which can impact performance and cognitive function. Even if you feel only slightly drowsy, you may still have a tough time focusing, learning or memorizing.
New research suggests that significant and chronic sleep deprivation may even have long-lasting negative effects on the brain.