Sex with another person, with an orgasm, was perceived to have a relatively stronger effect on men compared to women in terms of sleep quality; activity without orgasm was, to men, sleep-impairing

A national survey on how sexual activity is perceived to be associated with sleep. Ståle Pallesen et al. Sleep and Biological Rhythms, December 3 2019. https://link.springer.com/article/10.1007/s41105-019-00246-9

Abstract: There is a paucity of studies investigating how sexual activity is perceived to influence sleep, despite conceptions about significant gender differences regarding this issue. In all, 4000 persons, aged between 18 and 55 years, were randomly drawn from the Norwegian Population Registry and invited to participate in a postal survey. The respondents were asked how sexual activity with another person, with or without orgasm, and how masturbation, with and without orgasm, influenced sleep latency and sleep quality. A total of 1080 persons participated (response rate 28.2%) of which 56.1% were women. The mean age of the sample was 38.7 years (SD = 10.8). Sexual activity with an orgasm was perceived to have a soporific effect by both men and women. Sexual activity with another person, with an orgasm, was perceived to have a relatively stronger effect on men compared to women in terms of sleep quality. Sexual activity without an orgasm was by men reported to have a sleep impairing effect, whereas the perceived effect reported by women was equivocal. Sexual activity with orgasms was perceived as having a soporific effect in both men and women. Sexual activity without an orgasm had an equivocal perceived effect on sleep.

Keywords: Gender differences Orgasm Sexual activity Sleep onset latency Sleep quality Soporific effect


Discussion

The mean self-reported habitual sleep onset latency
reported by the sample was somewhat longer than normal
for young adults, albeit within normal range for middle
and older adults for both men and women [15]. Generally,
sexual activity with orgasm was perceived to shorten sleep
latency as well as improve sleep quality in both men and
women. This is in line with previous notions that orgasm
has soporific effects [6, 7, 9], and supports as such our
first hypothesis stating that orgasms following sexual
activity generally will be perceived to have a soporific
effect, albeit larger for men than for women. The exact
mechanism behind the soporific effect of orgasms is not
clear, but it may be attributable to the release of neurohormones
such as oxytocin, prolactin, and endorphins that are
assumed to have relaxing properties [16–18]. The effect
seemed to be larger for men than for women, especially
concerning orgasm following sexual activity with another
person. The positive perceived effect on sleep of sex with
an orgasm was also reported by the only previous survey
on this topic, but in the previous survey no gender differences
were found [9]. The gender difference regarding the
perceived soporific effect of masturbation with orgasms
was, however, not significant, a finding in line with the
aforementioned survey [9].
The difference score (effect of masturbation with an
orgasm—effect of sexual activity with another person with
an orgasm) was negative for men, but neutral for women in
terms of sleep latency. Thus, regarding sleep latency, men
perceived a greater soporific effect of sexual activity with
another person, with an orgasm, compared to masturbation
with an orgasm, whereas no significant difference was
reported by women. The difference score in terms of sleep
quality was negative for both men and women. Still, it was
significantly larger for men, implying that men, compared
to women, seem to experience greater soporific effect of
sexual activity with another person, with an orgasm, compared
to masturbation with an orgasm. Hence, sex with
another person, with an orgasm, had a stronger perceived
soporific effect for men than women (both for sleep latency
and sleep quality) compared to masturbation with an orgasm.
This lends support to our second hypothesis (masturbation
followed by orgasms relative to orgasms following sex with
another person will be perceived to have relatively stronger
soporific effect for women compared to men). One possible
explanation to this finding is that men, according to some
studies, have a higher energy expenditure during intercourse
than women [19], which may promote sleep [20]. However,
not all studies have shown that men spend relatively more
energy during sexual activity than women [21], and since
sexual activity often is of relatively short duration [22]
potential differences in gender expenditure during sexual
activity is not likely to explain gender differences concerning
the perceived soporific effects of sexual activity on sleep.
Another explanation to these gender differences is that men
have a stronger and more biologically and genitally sexual
drive, whereas women’s sexual drive to a larger extent is
romantically driven with a higher emphasis on intimacy [10,
11]. This view seems congruent with models of sexual selection
which posit that males invest less in the offspring, have
a higher reproductive rate and benefit more from mating
multiply than women [23].
Hence, when having sex with another person women generally
may put more emphasis on the relationship, whereas
men may put more emphasis on sexual gratification [10, 11,
23]. This may contribute to men easier falling asleep after
sexual activity with another person ending in orgasm, compared
to women, as men at this point may have obtained their
goal, whereas women still may want emotional intimacy or
confirmations about the relationship. It is also known that
most men following orgasms have a refractory period where
they cannot experience further erection or orgasms, whereas
women’s postorgasmic genital arousal is more variable [24]
which may influence the soporific effects of sexual activity
differently across genders.
According to our third hypothesis, sexual activity without
orgasm was expected to have no influence on sleep.
However, men actually reported longer sleep onset latency
and poorer sleep quality both when sexual activity with
another person and masturbation did not provide orgasm.
For women, this was only the case for sleep latency following
sexual activity with another person without orgasm.
Women reported no effect on sleep onset latency following
masturbation without orgasm, and no effect on sleep quality
when sexual activity with another person or masturbation
did not end in orgasm. Taken together, these findings show
that men seem to be negatively affected by sexual activity
without an orgasm, whereas women appeared to respond
less and more neutral to this. In this regard the present findings
are not in line with findings reported by the previous
survey by Lastella and colleagues, where it was suggested
that sexual activity, whether or not ending in orgasms, had a
perceived soporific effect. However, it seems that the questions
used in the previous survey were somewhat blurred
in terms of absence of orgasms explicitly [9], which might
explain the discrepancy in results. The third hypothesis was
thus not supported for men, and only partly supported for
women. Overall, it seems that lack of orgasm following
sexual activity is reported to be more frustrating for men
than for women, leading to perceived poorer sleep for men
compared to women. This may again reflect different emphasis
on behalf of men (e.g. sexual) compared to women (e.g.
intimacy) when it comes to sexual activity. It is also known
that sexual encounters more often end in orgasms for men
compared to women [25], hence lack of orgasm may thus
be more frustrating and sleep impairing for the male gender.

Limitations and strengths

The response rate of the present study was low, despite the
fact that the questionnaire was short and up till two reminders
were sent and material reinforcement (gift card lottery)
was used. However, the low response rate can probably be
explained by the sensitive (sexual) topic being investigated
[26]. It should be noted that low response rates do not imply
that results are invalid [27]. Still, we acknowledge that the
findings should be replicated in future studies. Although
similar to those used in a recent survey [9], the questions
about sexual activity’s perceived effect on sleep were constructed
for the purpose of the present study, hence their
psychometric properties are unknown. This is a limitation
and future research efforts should be taken to establish items
for this topic, for example by the method of Delphi [28].
Questions about sexual behaviors are sensitive by nature,
hence it cannot be ruled out that some did not answer truthfully.
However, care was taken to inform about how the data
would be registered and confidentiality ensured. In addition,
self-completion questionnaires were used as this seems to
result in more valid reports than interviews [29].
It should be noted that the questions were quite general
(sexual activity with another person or masturbation), and
future studies on this topic should therefore differentiate better
between different sexual behaviors (e.g. sex with a new
vs. familiar partner) and also assess their duration to investigate
how sleep is affected by them. In some of the analyses
the number of respondents was lower than the total sample,
as those answering “not relevant” were left out of the analysis.
The effect of sexual behavior on sleep was evaluated
retrospectively, which may render the responses vulnerable
to recall bias, thus the use of diaries in future studies on
this topic is encouraged [30]. It should also be noted that
only two sleep outcomes were evaluated (sleep onset latency
and sleep quality), as these were regarded most sensitive
to potential soporific effects of sex. Still, future studies
should include a wider array of sleep variables as outcomes
[31]. The present study was based on subjective rating of
sleep only, hence the findings should be corroborated by
objective sleep measures in the future. As orgasms may be
described along several dimensions, and since there may
be some gender differences in this regard [32], this should
be taken into consideration in future studies on this topic.
The present study did not differentiate between phases of
the menstrual cycle for the female respondents, although
this may influence both sleep [33] and sexual behavior [34].
Hence, future studies should take this into account. Prospect
research should in addition aim at identifying variables
beyond gender that might explain variance in the soporific
effects of sexual activity.
In terms of strengths, it should be noted that the present
study is one of the first large surveys that has addressed the
soporific effect of sexual behavior on sleep and contributes
as such with novel findings on a topic that is often debated
and heavily surrounded by myths. The sample was drawn
from the Norwegian Population Registry, which increases
the generalizability of the present findings. The sample was
weighted by the discrepancy between the general population
and sample characteristics in terms of age and gender, and
thus corrected for different response rates among subgroups.