Herbenick and her co-author Dr. J. Dennis Fortenberry, professor at the Indiana University School of Medicine, evaluated the responses of 370 women aged 18 to 63, who responded to their query online.
"We didn't know how many women we would find and it turns out, it wasn't that difficult," she said. "In five weeks, we found 100 women who had experienced orgasm and a couple of hundred others who didn't have orgasm but felt highly aroused and close to orgasm."
Researchers sent emails to various web sites geared to fitness and health. Of the respondents, 124 said they had experienced exercise-induced orgasm (EIO) and 246 reported exercise-induced sexual pleasure (EISP).
Most were in a relationship or married, and about 69 percent identified themselves as heterosexual.
Some older women told them that they had first experienced EIO or EISP in childhood during the President's Challenge, a fitness initiative that was launched in the 1960s. One woman said she had attained orgasm during exercise, but never when she had marital sex.
Other key findings of the study were that those who had experienced EIO and EISP had done so on more than 10 occasions. Most said they were self-conscious when it happened in public places, but about 10 percent could not control their experience.
Most said that when it occurred, they were not sexually fantasizing.
Of the EIO group, 51.4 percent reported experiencing an orgasm in connection with abdominal exercises within the previous 90 days.
Sheila Hageman, a mother and blogger from Stratford, Conn., said she has experienced "pleasure and even orgasmic like feelings" without fantasy or stimulation during yoga exercises.
"It usually happens after lots of sun salutations when I'm pretty drenched in sweat," said Hageman. "My whole is body buzzing from the movement and my mind enters this totally transcendental, but at the same time grounding, burst."
She's had the same experience with breathing exercises -- "the snapping in of your belly in a meditative state."
Terri Walsh, owner of ART Studio NYC, said of coregasm, "I believe it totally."
"I never had anybody have an orgasm in my presence -- as far as I know," said Walsh, 48. "But I definitely heard about it in my spinning classes. A lot of exercise, when it's done properly, can get you in tune with your body. Sometimes you get in tune with it quicker than your mind can."
Walsh said she has also heard of women having orgasms during yoga with deep abdominal contractions that can expand to the pelvic floor.
"Sometimes "it's a surprise to the woman who's getting it," she said.
Herbenick said that research will continue in order to help those who may never have experienced orgasm.
"These data are interesting because they suggest that orgasm is not necessarily a sexual event, and they may also teach us more about the bodily processes underlying women's experiences of orgasm," she said.
The study also might normalize the experience for women, or possibly enhance arousal during masturbation or sex with a partner, according to Herbenick.
"It may be that exercise -- which is already known to have significant benefits to health and well-being -- has the potential to enhance women's sexual lives as well," she said.