Sleep Late to Restore Brain Power

by Carole Jackson, Bottom Line Health

Oh boy, do I have good news to share!

Evidence demonstrates that sleeping in on the weekend is a smart idea after a tough week at work (or anywhere else). I’ve been known to sleep late myself on occasion, but always with a twinge of guilt, since we’re told that it’s better to go to sleep and get up at the same time every day. But juggling my job, kids, household tasks and other requirements all week sometimes leaves me weary and sleep-deprived by Friday afternoon — and I bet you know exactly how I feel.

Americans have a sleep debt that makes the national budget deficit look minor, warns Matthew Edlund, MD, MOH, an expert on rest, biological clocks, performance and sleep based in Sarasota, Florida, and author of the new book, The Power of Rest. Sleep is as important to health as food and water, and we should stop feeling guilty for allotting time for our bodies to rest, recharge and regenerate, he said.

Here’s Proof…

At the University of Pennsylvania School of Medicine, researchers conducted a study of the effect of sleep deprivation on the brain power of 159 healthy adults aged 22 to 45. A control group of 17 spent 12 consecutive days in the sleep lab — 10 hours in bed each night for seven nights — while the others spent 10 hours in bed for the first two nights, then were in bed only from 4 a.m. to 8 a.m. for five consecutive nights. Next, this group was assigned randomized amounts of recovery sleep, up to 10 hours per night.

All participants completed 30-minute computerized tests to assess their levels of alertness and neurobehavior performance every two hours while awake — and no one will be surprised to learn that in comparison with those who had adequate sleep, people with restricted sleep experienced:

  • Impaired alertness
  • Shortened attention span
  • Reduced reaction time.

Why You Need a Vacation

But here’s the happy finding: Normal function (alertness and performance, as above) was restored in sleep-deprived participants after just one solid night of recovery sleep — 10 hours, or the equivalent of squeezing in extra shut-eye on Saturday morning after a long week. (The more recovery sleep, the higher the scores.) In contrast, participants whose sleep continued to be restricted to an average of four to six hours per night performed poorly on tests and continued to get worse as their restricted sleep continued. Researchers also warned that even 10 hours of sleep in one night is not enough to bounce back if you continually push yourself too hard and burn the candle at both ends. Dr. Edlund said that, in fact, many studies have shown that even a few weeks of normal sleep won’t make up for a longtime habit of sleep deprivation — and he added that nowadays people rarely know what it’s like to feel fully rested. In that case, it is likely to take more than a day — think many weeks, and that’s only if you don’t go back to your old ways — to get back to par… which is why we need to take vacations!

These results were published in the August 2010 issue of the journal Sleep.

Just as we don’t expect our bodies to function without adequate nutrition, we can’t expect to feel fully fueled and alert without sufficient sleep, Dr. Edlund told me. The best scenario, of course, is to not allow yourself to become sleep-deprived in the first place — but this is not always possible. Most people require seven or eight hours a night to be at their best the next day. But when that doesn’t happen, we now know that you can get tremendous benefit from snoozing a little longer even for just one morning. It gives your brain time to recover and reboot — you’ll be more focused, productive and energetic as a result.


Matthew Edlund, MD, MOH (masters in occupational health), Center for Circadian Medicine, Sarasota, Florida. Dr. Edlund is author of The Power of Rest: Why Sleep Alone is Not Enough: A 30-Day Plan to Reset Your Body (HarperOne). Visit his Web site at