Menstrual cycles can vary and be inconsistent among female athletes. Physicians and other providers could miss important health problems if they downplay athletes’ cycle changes or differences.

A new study shows that a tool, called the Health and Reproductive Survey (HeRS), can assess menstrual function in physically active females.1

“It’s clear to me that the menstrual cycle should be used as a vital sign in females,” says lead author Donna Duffy, PhD, associate professor in the department of kinesiology, associate director at the Center for Women’s Health and Wellness, and co-director for the Female BRAIN Project at the University of North Carolina at Greensboro.

The menstrual cycle can provide information about a patient’s endocrine system, bone health, development, and temperature regulation. “I came to the conclusion that we need to treat the menstrual cycle as a vital sign, and I’m not the first person to suggest that,” Duffy explains. “It’s critically important that we look at [menstruation] in overall female health.”

This is true for athletes playing on an organized team or for a 45-year-old woman training for a marathon. “There’s a lot to consider on how the menstrual cycle influences and regulates the health of females,” Duffy says. Menstrual cycles can cease in athletes and patients who are very active physically, she notes.

Duffy and colleagues focused on exercising females — not just college-level and professional athletes. “We know female athletes are on teams and compete with each other and train with each other,” Duffy says.

But it is more challenging to understand the menstrual cycle effect on a woman older than age 40 who has begun marathon training. “The increase in her physical activity will have implications for her health,” Duffy says. “It’s well-accepted and established in the literature that physical activity is good for us; we have to move our bodies. But what are the byproducts of human movement that are not related to female athletes participating on a team? How are women’s bodies impacted and affected by movement beyond what we would consider the female athlete?”

HeRS was designed to learn retrospective information, based on a person’s stage of life. It includes a time frame before the patient turned 18 years of age, then ages 19-24 years, and then ages 25-40 years. “We ask them to give us information about how their menstrual cycle was impacted, based on their level of activity in that time of their life cycle,” she says. “Some women reported their menstrual cycle stopped. Because their energy availability wasn’t enough to sustain menstrual demands, endocrinological demands of their body, their menstruation stopped.”

Other people reported that they played harder when in the middle of bleeding. Women of different age groups reported how their menstruation kicked up their energy level a notch, enabling them to perform better and to feel better while exercising, she adds.

Duffy played field hockey and experienced an irregular menstrual cycle throughout her life. “I have polycystic ovary syndrome, so I never had a regular period in my life. I wasn’t diagnosed until my mid-40s,” she notes. “I was so relieved in high school and college that I wasn’t having the same menstruation issues of colleagues.”

After her diagnosis, she realized that her lack of a period for months — even up to 18 months — at a time was a health problem that needed to be addressed. As she ages, she could be at increased risk for various diseases affected by estrogen.

Experiences similar to Duffy’s can affect athletic and active women and need more attention from reproductive health providers.

“My hope — and the hope of the authors on this paper — is that if you have someone in your clinic or practice who is having issues with the menstrual cycle, you will look at their physical activity levels to see if there’s any connection there,” Duffy says. “We hope HeRS eventually gets into the hands of clinicians, athletic trainers, and women’s health practice — the people who see women every day for their reproductive health.”

This area of women’s health often is overlooked. “I think one of the opportunities with HeRS is this type of survey tool allows for longitudinal menstrual tracking of symptoms, side effects, and different characterizations,” Duffy explains. “This type of understanding shows how physical activity and exercise can influence overall women’s health — not just reproductive health. We hope it will have an impact on community practitioners.”


  1. Duffy D, Yourkavitch J, Bruinvels G, et al. The development and initial validation of the Health and Reproductive Survey (HeRS). Womens Health (Lond) 2021;17:17455065211004814.