Napping on night shifts may improve thinking later, not straight after waking

The review

1. 01

   Who took part

   The review pooled 494 working-age adults from 18 studies, with an average age of about 27. Most studies were run in labs, and six were in real workplaces.

2. 02

   What they did

   One group took a nap of about 40 minutes, starting around 2 am on average. The other group stayed awake, either working, resting or doing something quiet. Thinking was tested before the nap and at set times afterwards.

3. 03

   What happened

   Overall thinking was better 31 minutes or more after the nap, but not in the first 30 minutes after waking. Attention improved, while memory got worse straight after waking. The paper's numbers don't always agree, so read the sizes with care.

What the review found

1. HelpedFocus

   Across 13 studies, a nap on a night shift improved attention from 31 minutes after the nap.

   Pooled analysis of 13 studies · vs people who did not nap · ⚠ mixes trials with other kinds of study

2. MixedOther outcomes

   In 18 studies, napping did not change overall thinking in the first 30 minutes, but later it helped.

   Pooled analysis of 18 studies with 494 people · vs people who did not nap · ⚠ the studies disagreed a lot; mixes trials with other kinds of study

Source