According to researcher Debby Herbenick, co-director of the Center for Sexual Health Promotion at the University of Indiana, the results add qualitative and quantitative data in a field that has been little studied. Alfred Kinsey and his colleagues described this phenomenon for the first time in 1953, when they discovered that about 5 percent of the women mentioned that he had met orgasm tied to physical exercise. However, they could not know the true prevalence because most of these women gave this information without being asked directly.

Since then, reports of so-called "nucleorgasmos", so named because of its apparent relation to the abdominal muscle exercises, have circulated in the media for years.

"Despite the popular media attention, little is known scientifically about the exercise-induced orgasms," the researchers say in a special issue of the journal Sexual and Couple Therapy published in print this month.

Pleasure in the gym

Herbenick and colleagues used surveys "online" to collect your data, including responses from 124 women who had experienced exercise-induced orgasms and 246 women who reported sexual pleasure induced by exercise. Most participants were women between 18 and 63, had a relationship or were married and 69 percent were heterosexual.

The researchers found that about 40 percent of both groups of women had experienced pleasure or orgasm induced by exercise in more than 11 times in his life. Most women in the group who had experienced an "orgasm" said they felt a level of discomfort when exercising in public places.

Women who had experienced an "orgasm", said that when it happened they were having a sexual fantasy or thinking about someone who would feel attracted.

The abdominals are the best

The investigation revealed that orgasms tend to occur after several sets of crunches or other abdominal exercise, rather than after a couple of repetitions.

"We have had at least one woman in the study who was a virgin, and was delighted to enjoy these experiences in the gym," said Herbenick.

Researchers are not sure why certain exercises induce orgasm or sexual pleasure, but hopes to unravel the trigger Herbenick along its your job.

Research has different implications for women's sexuality. On the one hand, orgasm and sexual desire has led, as always, the list of sexual concerns of women, with about one in four women who do not reach orgasm during sex.

Second, scientists have long debated the evolutionary context of the female orgasm and its relationship to sexuality and reproduction. However, if many women experience orgasm during exercise is not related to sex, then the orgasm induced by exercise may reveal the relationship between sex and reproduction.