Previous research has indicated that good sex helps people doze off easier. A survey of Norwegian residents published in late 2019 found this pattern, for instance. But these studies have largely been cross-sectional and retrospective, meaning that they ask people to recall their sex and sleep habits at a single point in time, which might then lead to less accurate or biased responses. So for their new research, scientists at the University of Groningen in the Netherlands wanted to address some of these shortcomings.
They recruited over 250 participants to take part in their study. The volunteers filled out a survey at the beginning, similar to other cross-sectional studies. But they then also kept a diary detailing their sleep and any sexual activity they performed for the next two weeks. This type of record-keeping is known as a longitudinal study.
Based on the initial survey responses, the researchers found a clear link between better sleep and either having sex with someone that led to orgasm or masturbation with orgasm. These improvements included greater self-reported sleep quality and shorter sleep latency (the time it takes to fall asleep). When they next looked at the diary results, however, they found that only sex with orgasm was associated with better sleep. The findings were published earlier this January in the Journal of Sleep Research.