Sleep on it: A pilot study exploring the impact of sexual activity on sleep outcomes in cohabiting couples

Objective: The main aim of this pilot study was to examine the impact of sexual activity on objective and subjective sleep parameters. 

Methods: A repeated-measures counterbalanced, cross-over design with three conditions - no sex, solo masturbation, and partnered sex was employed with cohabiting couples. In this pilot study 14 individuals participated in the study (7 females, 7 males; mean age 29.9 ± 3.4 years). Sexual activities and sleep were monitored for 11 consecutive nights using a portable polysomnography system (DREEM3) and daily sex and sleep surveys. 

Statistical analyses: Linear mixed models were employed to examine differences in sleep, readiness, and motivation following three conditions (i.e., no sex, solo masturbation, and partnered sex). Cohen's d effect sizes with 95% confidence limits were also calculated for pairwise comparisons between conditions with the effect of magnitude interpreted as follows: small = 0.2, medium 0.5, large 0.8, very large 1.0. Wilcoxon Signed-Rank tests were conducted to compare the sleep stage concordance between partners across conditions. 

Results: Participants attempted sleep considerably later following the solo masturbation and partnered sex conditions compared to the no sex condition (p =.004). Wake after sleep onset and sleep efficiency improved considerably following solo masturbation and partnered sex compared to no sex (p <.05). No differences were observed across conditions for subjective sleep (p >.05). Sleep stage concordance for rapid eye movement sleep was longer when participants slept together regardless of whether they engaged or did not engage in sexual activity (p <.05). 

Conclusions: Engaging in sexual activity, whether solo masturbation or partnered, significantly enhanced objective sleep quality by reducing wakefulness after sleep onset and improving sleep efficiency. Objective wake up time, sleep duration, sleep latency and subjective sleep measures showed no differences postsexual activity, potentially attributable to the small sample size and the inclusion of only healthy sleepers. Future research should focus on expanding the sample size and incorporating participants with sleep disorders to thoroughly investigate if sexual activity before bedtime can improve sleep.