If you are a sleep-deprived office worker, you might find a lunchtime nap gives you an extra energy boost in the afternoon. For those working on shifts, napping is considered indispensable since it helps maintain your alertness and energy throughout the day. A group of Japanese scientists compared the effectiveness of two different napping patterns: a 120-minute monophasic nap (one-nap group) and a 90/30-minute split nap (two-nap groups) during a 16-hour simulated night shift. 41 females participated in the study, of whom 15 were in the no-nap group, 14 in the one 120-minute nap group and 12 in the split nap group. Participants were examined using the Uchida-Krapelin test every hour between 16:00 to 09:00. The one-nap group showed a significant increase in drowsiness from 04:00 to 09:00, whereas the two-nap group reported an intensifying drowsiness between 07:00 and 08:00. In addition, the longer the total sleep time, the worse the fatigue.

Furthermore, the researchers assessed the relationship among sleep latency, body temperature and nap patterns. It was found that the one-nap group had a lower body temperature post-nap compared with the two-nap and the no-nap groups. Considering the correlation between lower body temperature and increased drowsiness, they believed that the increased drowsiness in the one-nap group may have stemmed from the lower body temperature in the morning. However, shorter sleep latency was found to be associated with a higher body temperature, increased drowsiness and worse fatigue after the 90-minute nap. The trend reported in the study may pave the way for formulating protocols to overcome sleepiness in the workplace.

Reference:

Oriyama S. Sci Rep. 2023 Jun 18;13(1):9862.