Satisfactory sexual intercourse for couples lasts from 3 to 13 minutes, contrary to popular fantasy about the need for hours of sexual activity, according to a survey of U.S. and Canadian sex therapists.

Penn State Erie researchers Eric Corty and Jenay Guardiani conducted a survey of 50 full members of the Society for Sex Therapy and Research, which include psychologists, physicians, social workers, marriage/family therapists and nurses who have collectively seen thousands of patients over several decades.

Thirty-four, or 68 percent, of the group responded and rated a range of time amounts for sexual intercourse, from penetration of the vagina by the penis until ejaculation, that they considered adequate, desirable, too short and too long.

The average therapists' responses defined the ranges of intercourse activity times: "adequate," from 3-7 minutes; "desirable," from 7-13 minutes; "too short" from 1-2 minutes; and "too long" from 10-30 minutes.

"A man's or woman's interpretation of his or her sexual functioning as well as the partner's relies on personal beliefs developed in part from society's messages, formal and informal," the researchers said. ""Unfortunately, today's popular culture has reinforced stereotypes about sexual activity. Many men and women seem to believe the fantasy model of large penises, rock-hard erections and all-night-long intercourse. "

Past research has found that a large percentage of men and women, who responded, wanted sex to last 30 minutes or longer.

"This seems a situation ripe for disappointment and dissatisfaction," said lead author Eric Corty, associate professor of psychology. "With this survey, we hope to dispel such fantasies and encourage men and women with realistic data about acceptable sexual intercourse, thus preventing sexual disappointments and dysfunctions."

Corty and Guardiani, then-undergraduate student and now a University graduate, are publishing their findings in the May issue of the Journal of Sexual Medicine, but the article is currently available online.

The survey's research also has implications for treatment of people with existing sexual problems.

"If a patient is concerned about how long intercourse should last, these data can help shift the patient away from a concern about physical disorders and to be initially treated with counseling, instead of medicine," Corty noted.