17:47 PM

How Your Birth Control Affects Your Period (And What That Means for Your Running)

Women’s Running Magazine discusses how birth control affects the menstrual cycle and how it may influence strength, power and injury risk for runners according to experts including HSS physiatrist Ellen Casey, MD.

Dr. Casey encouraged women to see their menstrual cycles as a benefit, as runners have a risk of developing low energy availability and a related syndrome called relative energy deficiency in sport (RED-S). This occurs when the amount of energy you take in – in other words, how much you eat – isn’t enough to cover both your body’s basic functions and the energy you expend while running. Unlike men, women who menstruate have an early warning sign they’re headed down the path toward underfueling—irregular cycles at first, and eventually, amenorrhea, or losing your period altogether.

“The treatment for amenorrhea due to low energy availability is to optimize nutrition,” said Dr. Casey. Simply taking a pill that produces withdrawal bleeding doesn’t address the issue of underfueling. Furthermore, if you can’t tell whether you’re having a natural period, it’s harder to know if treatment for amenorrhea is working.

In women with the female athlete triad (low estrogen levels and insufficient calories increasing the risk of stress fractures) and low bone density, the birth control pills may actually do further harm. Estrogen protects your skeleton—but the type of synthetic estrogen in birth control pills doesn’t have the same effect. Shots have shown an even stronger link to low bone mineral density, added Dr. Casey.

Dr. Casey advised women to discuss all options for birth control with a physician —preferably, one who knows about and understands their running habits and priorities. Be sure to share information about your injury history, especially if you’ve had stress fractures. All this can help you work together to find the best option for you, she cited.

Read the full article at Womensrunning.com.