NASA researchers found a simple way to improve alertness by a whopping 54%

Are you familiar with the afternoon trough, that drop in mental energy that hits most of us between 2 pm and 4 pm?

As it turns out, that’s perfectly normal. In a recent podcast interview, sleep expert Prof. Matthew Walker explained that we evolved to experience a dip in alertness during that time of day.

However, NASA researchers found that we can improve alertness in the afternoon by a whopping 54% – and job-related performance by 34% – by taking a brief nap. That simple practice is the third variant of non-sleep deep rest, or NSDR.

Similar to Yoga Nidra and self-hypnosis, we rarely drop into deep stages of sleep during a brief nap. And like sleep, brief naps improve our mental energy and productivity. 

They do so by reducing what scientists call sleep pressure: From the moment you wake up and throughout your day, a chemical called adenosine builds up in your brain. It drives sleep pressure and tells your brain when to be tired. Like sleep, brief naps reduce the levels of adenosine – and thus alleviate some of that sleep pressure. That’s why napping is one of the best ways to recharge during the natural slump most of us experience in the afternoon. 

However, both duration and timing matter. First, don’t nap longer than 26 minutes. When you do that, you put yourself at risk of entering deeper stages of sleep. The result, then, is what scientists call sleep inertia – a feeling of confusion and grogginess upon awakening. You probably know what that’s like: It’s how you feel when being woken up by something from deeper stages of sleep in the middle of the night.

Second, don’t nap too late. Again, naps alleviate sleep pressure by decreasing the levels of adenosine in our brain. Yet, in the evening, high levels of adenosine are precisely what we need. Taking a nap too late in the day will take away that sleep pressure and make it harder to fall asleep at night. Thus, make sure not to nap later than 8 hours before your typical bedtime. And if you have trouble falling asleep at night, don’t nap at all.

In a nutshell, brief naps are great for improving your alertness and productivity when the afternoon trough hits. Go for naps of 26 minutes or shorter. Take them no later than 8 hours before bedtime. And avoid them entirely if falling asleep at night is challenging for you. Viva la siesta!

If you liked this post, please share it with others:

Until next week,
Christian