New York, Oct 23 (UNI) A short afternoon nap can be good for heart and overall health, a new study revealed.
The online edition of the Journal of Applied Physiology reveals why a nap might be beneficial for a healthy living.
The study conducted tests on nine healthy volunteers who did not usually nap. After sleeping for four hours the night before, the blood pressure of each was monitored under three conditions. In two sessions the volunteers relaxed, one time standing and once lying down, but did not sleep.
In the third session, the subjects fell asleep for no more than an hour.
The researchers found a significant drop in blood pressure when the volunteers slept, but not when they merely relaxed. And the drop in blood pressure occurred at the time right before falling asleep but not exactly in the nap Los Angeles Times reported. It's the brief period of anticipation of the coming snooze where cardiovascular benefits take place. Just lying awake, even if relaxed, doesn't help much, says Greg Atkinson, chronobiologist with the Research Institute for Sport and Exercise Sciences at Liverpool John Moores University, and an author of the study.
''Anything you gain in a restful state would be magnified by going to sleep,'' says Dr. Robert Downey III, chief of sleep medicine at Loma Linda University Medical Center who also recommends sleeping for a healthy heart but he cautions that a nap is only beneficial if it last 20 to 30 minutes.
''With a light nap, you get that soothing, biological benefit, but you don't have to fight your way back to consciousness,'' he added.
That's because brain waves slow considerably as you get drowsy, more so when you sleep. But after about 30 or 40 minutes, the brain goes into still-deeper sleep, and waking can make a person feel more dazed and weakened than rested.