A preliminary report relating frequency of vaginal intercourse to heart rate variability, Valsalva ratio, blood pressure, and cohabitation status.

The relationship between recalled frequency of penile-vaginal intercourse (FSI) and resting heart rate variability (HRV; an index of parasympathetic tone), resting diastolic blood pressure (DBP) and heart rate (HR) response to the Valsalva maneuver was examined in 51 healthy adults aged 20-47 (subjects scoring above the 86th percentile on the Lie scale of the Eysenck Personality Inventory (EPI) were excluded). As hypothesized, greater HRV and lower DBP were both associated with greater FSI (but not masturbation or non-coital sex with a partner) in cohabiting subjects, but not in non-cohabiting subjects. Valsalva ratio was unrelated to sexual behavior. Results are discussed in terms of both the modulating role of blood pressure on a number of psychological functions and the role of parasympathetic tone in HRV, FSI, and possibly pair-bonding.