NASA's research found that short naps can boost alertness by nearly 20% and task productivity by almost 50%, leading to the development of the 'NASA nap' culture. The most optimal time to nap during a long-haul flight is early on, as it sustains energy throughout the flight.

The 'nappuccino' combines caffeine intake with napping, allowing individuals to wake up refreshed without sleep inertia, as caffeine kicks in just as the nap ends.

Naps can be beneficial, but their effectiveness varies by individual; it's important to consider how long and when to nap.

To optimize napping, aim for a 20-minute nap between 1:00 PM and 3:00 PM, and avoid napping too late in the day to prevent disrupting nighttime sleep.

A 20-minute nap can enhance alertness and concentration without causing sleep inertia, which is the grogginess some people feel after longer naps.

For those who struggle with sleep, it's important to consider the timing and duration of naps, ideally taking them earlier in the day to avoid sleep disruption at night.

Research indicates that napping in older adults can be predictive of worse health outcomes and higher mortality rates, suggesting that it may reflect poor nighttime sleep quality.

Napping in the afternoon is fine, but avoid napping too late or for too long to prevent disrupting your nighttime sleep.

Naps can be beneficial for cognitive functions, but if you're struggling with insomnia, it's advised to avoid napping during the day as it can reduce your ability to sleep at night.