What Are the Physical Demands of Sexual Intercourse? A Systematic Review of the Literature.

The aim of this study was to systematically review the literature investigating the physical demands of sexual intercourse and to synthesize the evidence related to this research topic. Original studies published on PubMed, Scopus, and Web of Science up until April 2020 were examined. The Effective Public Health Practice Project scale was used to assess the methodological quality of each study. Eighteen studies analyzed physical demands during sexual intercourse through the physiological demands (n = 14) and kinematics (n = 4) of sexual intercourse. Sexual intercourse can elicit an energy expenditure of ~ 100 kcal (or ~ 6 metabolic equivalent units, METs) during the activity, mean heart rates between ~ 90 and ~ 130 beats per minute (bpm), and peak heart rates up to ~ 170 bpm. However, these physical demands may vary depending on health status, intercourse position, activity duration, intercourse phase, and sex differences. The movement pattern was cyclic in all positions and the greatest demands in lumbar spine flexion were found in the missionary positions for women. Missionary and side-lying positions elicited the greatest lumbar flexion movement in men. Regarding the movement of the hip joint during sexual intercourse, flexion, abduction, and external rotation mainly characterized the woman's movement while external rotation did so in the man. In conclusion, sexual intercourse may elicit moderate intensity physical demands, but these demands vary depending on contextual variables. In addition, not only studies combining physiological and kinematic analyses are necessary but also more high-quality studies need to be published in order to have a better understanding of the physical demands of sexual intercourse.