By Dr Jemma King
Across the world, from Mediterranean towns to Tokyo offices, people use naps to boost energy, creativity and resilience. Science now shows that these old traditions are grounded in wisdom – the right nap, at the right time, is one of the most powerful performance tools we have.
A strategically timed nap is a powerful tool that can turn a long painful ‘drag of a day’ into a day of efficiency, mental alertness and clarity, not to mention emotional stability. The science backs this up.
Brain wave (EEG) data shows that even short naps can help learning by bolstering declarative memory (factual information) and procedural memory (skills and actions), can improve emotional regulation and, for certain types of learning and skilled performance, produce gains comparable to a full night’s sleep.
Physiologically, naps decrease stress levels through reduced cortisol, the hormone that can give you that ‘tired but wired’ feeling in the evening. Regular napping habits have also shown cardiovascular benefits, including lower blood pressure and reduced heart stress.
However, it’s important to nap properly.
What is a nap?
A nap is generally defined as a sleep period shorter than 50 per cent of your main sleep duration and can range from a few minutes to several hours. Research shows that the most common nap length among adults is between 10 and 30 minutes.
Studies indicate short naps lasting no more than 30 minutes can give you a cognitive boost and increase alertness for up to three hours provided the nap predominantly consists of light NREM (non-rapid eye movement) sleep, especially stages N1 and N2.
Longer naps, typically exceeding 30 minutes, enter deeper sleep stages, which encroach on the nap danger zone, with significant consequences.
Sleep inertia
Have you had a nap and woken up totally disorientated and feeling like someone has taken a baseball bat to your skull? This phenomenon is called ‘sleep inertia’ and is described as feelings of drowsiness, disorientation and a decline in motor dexterity. Sleep inertia happens because your brain doesn’t switch back to full speed the moment you wake up, especially if you’re pulled out of deep sleep.
During deep sleep, brain activity slows right down, cerebral blood flow is reduced, particularly in the areas responsible for clear thinking, memory and decision making, and your body temperature drops.
When you wake suddenly, those regions take time to ‘boot up’, which leaves you feeling groggy, slow and confused. The effect is much worse if you wake during deep sleep rather than the lighter sleep stages, because your brain is in a more shut-down state.
Best timing for naps
Research from NASA found that pilots who took strategic naps showed improvement in task performance and improvement in alertness compared to those who did not nap. But timing is crucial for maximising nap effectiveness.
Human circadian rhythms naturally induce a decline in alertness during midafternoon, commonly around 2–3pm. Napping during this window aligns with your body’s innate ultradian rhythm and ensures you get optimal rejuvenation and alertness afterwards.
Optimal nap duration
If you have time during the day, you can opt for a 90-minute nap incorporating the full sleep cycle. This way, you naturally progress through light sleep, deep sleep and REM (rapid eye movement), giving your brain and body the benefits of each stage without waking in the middle of deep sleep, which causes the sleep inertia.
A full-cycle nap improves memory consolidation, boosts creativity and enhances problem solving and leaves you feeling more refreshed than fragmented short naps do. It’s particularly useful if you’re recovering from sleep debt, long work shifts, hangovers or preparing for a demanding task later in the day.
However, if you oversleep beyond 90 minutes or nap too late in the day, it will interfere with your night-time sleep pattern, so it’s best to plan longer naps before mid-afternoon.
Types of naps and their effects
Not all naps are created equal. Some naps sharpen focus and boost mood almost instantly, whereas others leave you groggy or even disrupt your night-time sleep.
Power nap (10–20 minutes)
Ideal for a quick boost in alertness and energy without entering deep sleep. These naps improve reaction time and focus without causing grogginess.
Cognitive nap (20–30 minutes)
Enhances memory and learning by allowing the brain to cycle through light sleep stages, which support information processing.
Restorative nap (60–90 minute)
Includes deeper sleep stages, such as slow-wave sleep and REM sleep, which are critical for creativity, problem solving and emotional balance. However, longer naps may cause sleep inertia.
Post-alcohol nap (approximately 90 minutes)
As alcohol is toxic for your system, your body will prioritise slow-wave sleep over REM, which gets pushed out, leaving you with hangxiety; therefore, a post-alcohol nap needs to include the full 90-minute cycle that includes the REM stage to reset the memory filing system.
Avoidant nap (variable)
A psychological kill-switch nap that involves deliberately forcing oneself into sleep as a primary strategy to escape acute emotional or cognitive distress. This nap can be adaptive initially after a high-stress event, but can become maladaptive if the trauma is not addressed.
The key is understanding which type of nap you’re taking, when to take it and what you want it to achieve.
Edited extract from Sleep First by Dr Jemma King (Wiley, $36.95), available at all leading retailers.