Generally speaking, if you suffer from insomnia, naps are usually best avoided.
That's because they reduce sleep pressure, so if you're trying to improve your sleep through sleep restriction therapy, naps can counter the very effect you're trying to achieve.
However, naps aren't all bad.
A recent French study found that naps can reduce the stresses imposed on the body due to sleep deprivation.
The research involved putting 11 healthy men between the ages of 25 and 32 through two separate three day sleep routines.
The first routine involved a night of eight hours of sleep followed by a night of two hours of sleep followed by a night of as much sleep as they wanted.
The second routine remained the same except participants were allowed to take two half hour naps the day after their night of restricted sleep.
Researchers found that after the night of sleep restriction, norepinephrine values increased. (Norepinephrine is a hormone that plays a key role in how the body regulates stress, the heart rate, blood sugar levels and blood pressure.)
When testing those who were able to take naps the following day, the increase in norepinephrine values was no longer present.
After a night of sleep restriction, individuals also had higher levels of Interleukin-6 - a protein that helps fight viruses. As with norepinephrine values, these levels were normalized after napping.
Interestingly, researchers also discovered that the advice of avoiding naps when trying to improve sleep is sound - those who didn't nap had higher levels of dopamine on their final recovery night (when they could sleep as much as they wanted) and they got more slow-wave (deep) sleep on their recovery night compared to the non-napping group.
Although this study was only small, it shows that naps can be beneficial for short-term sleep deprivation. Naps after a night of poor sleep can reduce stress and strengthen the immune system. However, those who napped didn't get the same dopamine boost or amount of slow-wave sleep the next night compared to those who didn't nap.
My advice? If you suffer from insomnia I still recommend avoiding naps as they can disrupt your sleep cycle and reduce nighttime sleep pressure. However, if you feel a nap is absolutely necessary make sure you limit your nap to around 45 minutes and avoid taking naps later than around 4pm.
Source: Endocrine Society
Last updated: July 14, 2015