==========English version, translated by ChatGpt======
Working night shifts can significantly affect both physical and mental health, particularly in terms of alertness and fatigue. According to a recent study, choosing the right sleep pattern is crucial for those who need to work at night, such as new parents.
Advantages of Split Napping at Night
Recent findings from Hiroshima University in Japan indicate that in a simulated 16-hour night shift, taking two separate naps — one of 90 minutes and another of 30 minutes (Two-nap) — is more effective at reducing morning fatigue and sleepiness than a single, longer 120-minute nap (One-nap).
Specifically, the two naps are scheduled from 22:30 to 00:00 and from 02:30 to 03:00. This arrangement better adapts to the human circadian rhythm, reducing sleepiness and fatigue.
Relationship Between Body Temperature and Sleepiness
The study also found that a single, longer nap results in a lower body temperature, which is associated with increased sleepiness. Therefore, choosing a segmented napping pattern not only enhances alertness but also maintains a more stable body temperature.
Summary and Recommendations
Based on these findings, it is recommended for night shift workers to opt for a segmented napping pattern, preferably during the periods of 22:30 to 00:00 and 02:30 to 03:00. This approach not only effectively reduces fatigue and sleepiness but is also speculated to be beneficial for new parents.
This discovery parallels previous research on sleep-deprived adolescents, which found that while the total duration of sleep is crucial, segmented catch-up sleep can be more effective under the same total sleep duration.