Birth control pills offer athletes the pros of a regular and predictable menstrual cycle but cons of the risk of muscle loss, weight gain, and decreased athletic performance. An IUD, a localized dose of progestin, does not have these risks. Another suitable birth control option for athletes is a progestin-only minipill which is less likely to disrupt training gains than a combined oral contraceptive pill, says women in sports expert Dr. Stacy Sims.
Reviewed by women’s expert Dr. Jill Krapf: What is the best birth control pill for female runners? This is a question I have gotten asked a lot of lately. Many mother runners need birth control for the obvious reason—we don’t intend to add more people calling us “mom” to our lives—as well as to help regulate or lighten our periods, among other reasons.
But hormonal birth control pills come with some potential side effects for athletes including weight gain, muscle loss, and decreased performance.
I went off the pill because several brands gave me migraine headaches. Doctors put me on it to try to get my period back after suffering from amenorrhea for many years. I finally stopped taking a hormonal birth control pill altogether almost a decade ago. Since then, I have watched friends struggle to find a pill that helped them regulate their periods, get their periods to return, or help with bone loss.
Indeed, studies do support that there are pros and cons of birth control pills for athletes.
Skip Ahead:
Pros of birth control pills for athletes:
- Consistent hormones
- Regular periods
- Control over when you have your period
- Less iron loss
Cons of birth control pills for athletes:
- Potential weight gain and fat mass
- Potential for decreased muscle strength
- Potential for decreased performance
- Potential for bone density loss
I spoke with a premier women’s health expert, Dr. Jill Krapf, associate director of The Center for Vulvovaginal Disorders and a professor at George Washington University, and reviewed the research on birth control pills for athletes.
To begin, let’s review the basics of what birth control pills are and how they work. Dr. Krapf gives us an overview.
Related: How Your Period Affects Your Running
What are birth control pills?
Most birth control pills are made up of two medications, Ethinyl estradiol, which is a form of estrogen, and progestin, which is a synthetic form of progesterone.
Almost all birth control pills have the same estrogen component in varying doses. The type, or generation, of progestins differ among various brands of the pill, explains Dr. Krapf.
The different doses of estrogen and types of progestin are the one reason why birth control pills affect people differently.
There are also birth control patches and a birth control ring, a small T-shaped device inserted into the uterus through the vagina, called an intrauterine device (IUD) that works in the same way as the pill.
IUDs may be hormonal by releasing progesterone or be non-hormonal.
Related: 36 Game-changing Hacks to Transform Your Running
How do birth control pills work?
Birth control pills are a hormonal birth control method. Birth control pills along with the Patch, the NuvaRing, the Mirena IUD, Depo-Provera, and Implanon, effectively shut down their normal hormonal cycles.
The progestins and estrogens from the contraceptive tell the pituitary gland not to produce FSH or LH and thereby suppress ovulation. They can also alter the thickness of the uterine lining, reducing the likelihood of the successful implantation of a fertilized egg.
Non-hormonal methods of contraception include the copper IUD, condoms, cervical caps, diaphragms, femidoms, and spermicidal gels and foams. These birth control methods keep sperm from reaching the egg.
Related: RED-S: The Danger Facing Female Runners
Do birth control pills affect athletic performance?
A big reason why I wanted to write this piece is due to a concern from many mother runners that birth control pills will hurt their performance. They’ve heard that birth control pills can make them slower. So, I did a review of the studies to see if this is true.
In summary, there is some evidence that birth control pills can hurt your athletic performance. However, there is no concrete evidence that what’s been observed in the lab translates into real results.
Birth control pills may reduce VO2 Max.
A very small study of 14 female athletes found a statistically significant reduction in VO2 Max in athletes taking an oral contraceptive compared to a placebo group.
There was also an increase in skinfolds in the group taking birth control pills (weight gain). However, there were no real changes in the measure of performance: anaerobic speed test, aerobic endurance, and isokinetic strength.
Birth control pills may reduce muscle mass.
A 2021 study found that oral contraceptives impair muscle gains in young women. The study found that female athletes taking birth control pills with progestin gained just over half a pound of lean mass over the 10-week study. This is compared to 3.5 pounds of muscle gained by the women not taking birth control pills.
Another (small) study, done in 2019, found that women taking birth control with estradiol increased the size of their muscles but not the strength. Women not taking birth control pills increased both the size and strength of their muscles.
Other studies have had inconclusive findings. It’s important to note that statistically significant data may or may not have clinical or performance relevance. By the same token, a statistically nonsignificant change may mean a big difference in performance for an individual athlete.
Birth control pills may make you gain weight.
The effects of weight gain from birth control pills are very individual. A review of 44 studies found that birth control pills do not generally cause weight gain. The Ethinyl estradiol can cause you to gain fat, and the progestin can cause water retention of 2 to 3 pounds on average. However, weight gain does not happen with every athlete or every birth control type.
Birth control pills may reduce bone density.
Some studies have found a correlation between the use of birth control pills and bone density loss (bone breakdown). Other studies have found that birth control pills can help improve bone density (bone buildup).
Related: How to Start Running Postpartum
Dr. Krapf explains that the variance in a woman’s weight, exercise, diet, and estrogen status can explain these different findings:
“If someone has low estrogen levels, which can result when negative energy balance suppresses the ovaries’ production of estrogen leading to loss of the menstrual period, the estrogen in birth control pills may be helpful to bone health.
However, if estrogen levels are normal, the data regarding exercise and birth control pills are less clear regarding bone health, with some studies showing a possible negative effect.”
How to tell if it’s time to switch your birth control pill?
If you’re a runner taking a birth control pill, you should pay attention to side effects to learn if you should change birth control pills or to another contraceptive method.
For example, if your estrogen is too low, you will spot between periods. And, if your estrogen it’s too high, you may experience nausea, weight gain, and breast tenderness. These are signs you may need to switch your birth control pill.
If you try a new birth control pill, you will know within a couple of months if it is the right one for you. Your periods should be
- regular with minimal spotting
- your mood should be stable
- your weight gain should be minimal,
- and your performance should not be lagging.
Should female athletes take birth control pills?
Well, that’s the question and it is very individual. If you are an athlete who struggles with irregular or heavy periods (and low iron), then taking a birth control pill may be helpful to you. If you’re a very competitive athlete that doesn’t want to risk potential muscle or bone loss, or decreased performance, then an alternative birth control method may be best for you.
Dr. Krapf says that while some research has found that birth control pills could hurt your performance—a lot of these findings don’t necessarily translate to real life.
“An analysis of studies on this topic indicated that there was likely a slight performance advantage for naturally cycling women compared to those that took birth control pills. However, the real-life implications are likely not meaningful and were certainly not strong enough to lead to a recommendation for athletes to not use birth control pills for performance reasons,” she explained.
What birth control should female athletes use?
Dr. Stacy Sims, the author of ROAR, advises female athletes who do not want to risk their performance gains but need to use birth control to use an IUD or progestin-only minipill.
“(An IUD) is a localized dose of progestin, so you don’t have systemic estrogen and progesterone. If an IUD doesn’t suit you, the next best option is a progestin-only minipill. This has fewer side effects and will be less likely to disrupt your training gains than a combined oral contraceptive pill,” she says.
However, it is YOUR decision as an individual athlete and runner (and mother runner).
You should examine the different birth control options you have and decide based on your own needs, demands, lifestyle, and recommendations from your doctor.
If you want a custom plan to fit your running goals this year, including running a marathon on your period!, check out my run coaching services. Also, be sure to check out my free training plans: