(WOMENSENEWS)—She was an avid runner who was used to pushing her body through the hard parts of a workout, but the teen was surprised that she had to force herself to enjoy sex. It hurt. It burned. It just wasn’t fun.

Eventually, her relationship ended, and when she entered a new one she expected the same thing. But this time, it was different. Sex didn’t hurt or sting. Sex was enjoyable and fun.

The young runner is like many other teens and women who experience discomfort during sex. A U.K.-based study found that 10 percent of females feel pain during vaginal sex. This pain, according to the researchers, is likely greater in teens because they generally have been sexually active for a shorter period of time, are less experienced and have had fewer partners.

In a survey of 12 sexually active girls, ages 15 to 18, in Westchester County, New York, Teen Voices found only two girls who didn’t experience pain or discomfort during sex. The girls surveyed, who agreed to be quoted about their private lives on the condition of anonymity, were going to elite colleges or were star players on sports teams. Despite the high bar they have for other parts of their lives, most of these girls were content with subpar, uncomfortable and even painful sex lives.

One high school senior, who has been with her boyfriend for nearly two years, has sex five to six times a week. She experiences pain sometimes, but nothing extreme enough to tell her doctor about. Instead, her and her partner “pull up our boots and get along with the process.” Most of the girls interviewed were in committed relationships.

The runner who didn’t feel pain with her second sexual partner said lubrication helped but she thinks the real issue was that she was “a lot more attracted to my [current] boyfriend than my ex-boyfriend.” She said it never occurred to her that she hadn’t been sexually attracted and that caused the pain.

“I thought there was something wrong with me,” she said. She never brought up the topic with her ex because she said she didn’t know how.

Discussing Discomfort

But not all girls feel awkward discussing discomfort with their partners. One teen surveyed relies on open communication to make sex enjoyable. “I’ll be honest, I’ll be like, ‘That kinda hurts, let’s switch positions or try another angle,’” she said. Soon to be a student at Barnard College in New York, she credits some of this to when she had difficulty using a tampon and her OB/GYN mother helped her. She also talks about her body and her sex life with her mother freely.

Fifty-eight percent of the girls in the Teen Voices survey predicted that someone with a vagina “will bleed the first time they have sex” and 100 percent said the first time will be painful.

Despite the expectations the girls had, “any blood with first penetration is more likely due to general vaginal tearing from lack of lubrication,” sex educator Emily Nagoski says in her book, “Come as You Are.” Nagoski writes that with the proper amount of lube, no one needs to bleed. This is a position the World Health Organization supports.

Starting off on the wrong foot can cause teens to get the wrong idea about what sex should feel like, and may let girls settle for something that is less than enjoyable.

“No matter the size of the sexual parts of either person [sex] doesn’t ever need to hurt,” said psychotherapist and certified sexologist Isadora Alman. The repercussions of painful sex differ from teen to teen, but Alman said it’s never good. “Sex is about pleasure. It’s not designed to hurt.”

Peggy Orenstein, author of “Girls & Sex” and “Cinderella Ate My Daughter,” told Teen Voices she credits “ignorance about the body, an overly-narrow definition of sex, a premium on male pleasure, an unwillingness to speak up against all of that” for the prevalence of painful sex among young girls.

“It’s on adults to start talking to girls a lot more frankly about their right to and capacity for pleasure in their intimate relationships,” Orenstein said.