How Effective Are Short Naps?

Short naps of 30 or 60 minutes did not show any measurable effects on mitigating effects of sleep deprivation, as reported in the journal sleep.

Researchers from Michigan State University were the first to measure the effectiveness of shorter naps, which are often all people have time to fit into their busy schedules in their study.

‘Short naps during day cannot replace a full night of sleep.’

"While short naps didn't show measurable effects on relieving the effects of sleep deprivation, we found that the amount of slow-wave sleep that participants obtained during the nap was related to reduced impairments associated with sleep deprivation", said Fenn, associate professor of MSU, study author and director of MSU's Sleep and Learning Lab.

Slow-wave sleep, or SWS, is the deepest and most restorative stage of sleep.It is marked by high amplitude, low frequency brain waves and is the sleep stage when your body is most relaxed. The muscles are at ease, heart rate and respiration are at their slowest.

When someone goes without sleep for a period of time, they build up a need for sleep even during day. When individuals go to sleep each night, they will soon enter into SWS and spend a substantial amount of time in this stage.

They recruited 275 college-aged participants for the study. The participants completed cognitive tasks when arriving at MSU's Sleep and Learning Lab in the evening and were then randomly assigned to three groups.

The first group was sent home to sleep; the second stayed at the lab overnight and had the opportunity to take either a 30 or a 60-minute nap; and the third did not nap at all in the deprivation condition.

The next morning, participants reconvened in the lab to repeat the cognitive tasks, which measured attention and place keeping, or the ability to complete a series of steps in a specific order without skipping or repeating them, even after being interrupted.

The group that stayed overnight and took short naps still suffered from the effects of sleep deprivation and made significantly more errors on the tasks than their counterparts who went home and obtained a full night of sleep.

Individuals who obtained more SWS tended to show reduced errors on both tasks. However, they still showed worse performance than the participants who slept.

These findings highlight the importance of prioritizing sleep in jobs like surgeons, police officers or truck drivers, where a 4% decrease in errors could potentially save lives.



Source: Medindia