Comment: The researchers seem to have conflated penile-vaginal intercourse and orgasm, but even so, the results may be indirectly relevant to Synergy.
J Sex Med.
2009 Jul;6(7):1947-54. doi: 10.1111/j.1743-6109.2009.01303.x.
Shindel, A. “Satisfaction (Sexual, Life, Relationship, and Mental Health) Is Associated Directly with Penile–Vaginal Intercourse, but Inversely with Other Sexual Behavior Frequencies: Brody S, Costa RM (Univ of the West of Scotland, Paisley, UK) J Sex Med 6: 1947-1954, 2009 §.” Yearbook of Urology 2010 (2010): 164-165.
Brody S1, Costa RM.
Abstract
INTRODUCTION:
Some sex therapists and educators assume that many sexual behaviors provide comparable sexual satisfaction. Evidence is required to determine whether sexual behaviors differ in their associations with both sexual satisfaction and satisfaction with other aspects of life.
AIMS:
To test the hypothesis that satisfaction with sex life, life in general, sexual partnership, and mental health correlates directly with frequency of penile-vaginal intercourse (PVI) and inversely with frequency of both masturbation and partnered sexual activity excluding PVI (noncoital sex).
METHODS:
A representative sample of 2,810 Swedes reported frequency of PVI, noncoital sex, and masturbation during the past 30 days, and degree of satisfaction with their sex life, life in general, partnership, and mental health.
MAIN OUTCOME MEASURES:
Multivariate analyses (for the sexes separately and combined) considering the different satisfaction parameters as dependent variables, and the different types of sexual activities (and age) as putative predictors.
RESULTS:
For both sexes, multivariate analyses revealed that PVI frequency was directly associated with all satisfaction measures (part correlation = 0.50 with sexual satisfaction), masturbation frequency was independently inversely associated with almost all satisfaction measures, and noncoital sex frequencies independently inversely associated with some satisfaction measures (and uncorrelated with the rest). Age did not confound the results.
CONCLUSIONS:
The results are consistent with evidence that specifically PVI frequency, rather than other sexual activities, is associated with sexual satisfaction, health, and well-being. Inverse associations between satisfaction and masturbation are not due simply to insufficient PVI.