How Hormonal Birth Control May Be Affecting Your Athletic Performance

Having a period is an inconvenient thing and the enticement of full ultimate Godly control by using hormonal birth control methods (like the pill) has been a life saver for some women. Knowing EXACTLY when your period will come, lessening the worse parts such as bleeding and cramping, and even for some completely getting rid of it. When you are planning an 18 week training cycle why would you not want to have that certainty and control? A while ago I wrote another blog about periodization for your period and how you can actually work with your cycle to take advantage of times of the month where you can really amp up training and other times where you need to back off and focus on recovery. Read all about it here. 

When searching the topic of hormonal birth control and athletic performance there surprisingly was not a lot of information available. I could find information about types of birth control, side effects, effectiveness, but nothing on how it might affect your athletic performance. I had first heard about it in a podcast but when I went to search I just wound up in dead ends. Knowing there must be others in my position I decided to go on a very long quest for information. I've been piecing information together for about a year now so hopefully you find some information that will be helpful to you and will lead you to your own search for information. I should also note that this is a blog post to offer another perspective and ultimately what works for you and your health is a very personal choice that should be decided on by you and your doctor.  

How Does Hormonal Birth Control Work?

Thanks to podcast episode, "Giving Birth the the Pill" on This Podcast Will Kill You, I've got the basic idea of how hormonal birth control generally works. This podcast was loaded with information on everything birth control related (types, effectiveness, benefits, disadvantages, etc). I encourage you to listen to the episode here (or talk to your doctor) if you would like more specific information but here is the information I got from the episode (paraphrased and summarized):

Your body starts the menstrual cycle with Day 1 being the first day of bleeding. Your in the "low hormone" phase where most of your hormones are present at low levels. Around day 14 you have a surge of estrogen which causes a surge in another hormone, LH, which triggers ovulation. The egg travels down the Fallopian tube to the uterus where it either is fertilized (resulting in pregnancy) or where it does not implant and sheds along with the lining of the uterus resulting in what we know as a "period." 

Combination forms of birth control contain estrogen and some synthetic form of progesterone. Combination types of birth control are the combination pill (very common), DEPO shot, the patch and Nuvaring. The hormones are constantly held in high levels in your body so that you never see the surge of estrogen that causes the release of an egg. Having constantly high levels of estrogen stops ovulation from ever happening. That works in combination with some form of synthetic progesterone which works by thickening the cervical mucus to inhibit sperm from entering the uterus. So no ovulation, inhibiting sperm and no pregnancy. 

Other forms such as the mini pill, hormonal IUD and implant are a synthetic progesterone only. These types also inhibit ovulation and thicken cervical mucus but also prevent the uterus from building an effective lining where fertilization could take place. Think of it as creating more of a "hostile" environment not inhabitable to an egg. Again, no ovulation, inhibiting sperm and hostile environment so therefore no pregnancy. Women tend to opt for these types because they do not contain estrogen which increases the risk of blood clots and some women find it can cause migraines and other complications. (1)

Because both forms make the lining of the uterus very thin, there isn't much to shed during a period. Less shedding of lining means a reduction in bleeding and a much more manageable period. With a device such as a hormonal IUD, the lining can become some thin that you won't even see bleeding when it sheds, therefore completely eliminating or drastically reducing the period altogether!

How Can Hormonal Birth Control Be Damaging?

The pill and other forms of hormonal birth control come with very little risk to health with blood clots being one of the main concerns. Birth control itself isn't really damaging to women and girls but masking symptoms of an underlying problem can be damaging

I have coached a lot of high school athletes and one thing that I have seen numerous times is a young girl either losing her period or still not getting a period when they reach the age of 16. A common reason for this in high school athletes is relative energy deficiency in sport (RED-S) syndrome. RED-S is not specifically having an eating disorder, RED-S is a combination of factors in an athlete that puts them in a chronically low energy state. RED-S is often a combination of not getting enough calories (that doesn't specifically mean disordered eating although that could be a factor), not enough sleep, not enough nutrients or protein, high stress levels, and over training. One or more of those factors can combine and put an athlete (male or female) at a low energy state which could result in female athletes having amenorrhoea (lack of a period). 

Once an athlete is in this low energy state, they can start to have endocrine dysfunction, poor sleep, inability to recover from workouts, increased levels of depression/anxiety and other symptoms that can have long term consequences. When a female athlete loses her period she has dysfunction in the production and uptake of estrogen which plays an important role in bone health. Poor bone health can then lead to brittle bones, stress fractures and more seriously, osteoporosis. Often what will happen is a doctor will not receive the whole story, see the loss or absence of a period and go right to what we know as, "the pill." That usually refers to the combination estrogen/synthetic progesterone once a day oral contraceptive pill. The upside is that the female athlete will receive estrogen through the pill to put her on the right track for bone health. The downside is that the original problem of the RED-S is not addressed. I find it dangerous that the pill can be used as a band-aid to cover up the original problem so if an athlete is over training and/or under fueling then that problem is not actually being fixed leading to a continuous cycle of injury and frustration in training. All things that are not conducive to promoting a lifelong healthy relationship with the sport.

How does hormonal birth control effect performance?

According to research by Dr. Stacy Sims, the combination forms of birth control can have "up to an 11% effect on performance potential." (2)  Let me do the math for you, 11% is about 52 seconds if we're talking about an 8 min mile. That's about 2 min 40 sec in a 5k. That's 22 min and 40 sec in a marathon! Now, that's not saying if you stop your hormonal birth control you're going to immediately drop 22 minutes off of your marathon time or immediately hit your Boston Qualifier, but over the course of time you might gain an extra edge to push past some of those barriers or plateaus you are facing. 

So what is it about hormonal birth control that affects performance? 

When on a form of hormonal birth control your body is exposed to "6 to 8 times the amount of hormones produced naturally." High levels of progesterone "increase muscle breakdown" in your body and high levels of estrogen "decrease the ability to hit high intensities in training" and "increase fatty acid use thus increasing fat gain." With specific methods such as the DEPO shot you "increase total body fat" and "your vessels lose the ability to dilate and contract, compromising circulation and thermoregulation." (3)

Our bodies naturally fluctuate between high and low hormone phases during a cycle. The low hormone phase being the easiest for optimal performance and the high hormone phase we have to work a little harder to do things like regulate temperature and access stored carbohydrates. If your goals take you over long distances in summer heat, circulation and temperature regulation become super important when reaching for a specific goal. And while you shouldn't be trying to lose weight (at risk of putting yourself at a low energy state) while training, you also don't want to increase your body fat percentage if you are putting 100% effort towards a specific time or race goal.

Hormonal birth control puts us constantly at this high hormone phase making it more difficult to reach high intensities, reducing our VO2 max capabilities and making it more difficult to build and repair muscle among other things. This is something that works against your fitness goals.

Do I have to choose between not getting pregnant and running fast?

No. But you might have to choose between how you want to manage your period and symptoms if you're interested in increasing your performance potential. In The Curious Climber Podcast, "Stacy Sims: Women Are Not Small Men" explains:

Don't use the (combination) pill to manipulate your cycle. There is no real period and the pill masks endocrine function. It makes it easier to cover up deficiencies. Specifically to performance downfalls, synthetic hormones are not identical to real hormones. They reduce the ability for max muscle contraction, cognition, hitting high intensities and adaptability. (4)

If you want to use hormonal birth control because it fits your lifestyle AND you want to maximize performance, then in that same episode she recommends the IUD.

You will still have naturally cycling hormones and go back to ovulating. You may have little or no bleeding because it causes you to have a thin lining in the uterus. You can use a temperature and ovulation predictor kit to keep track of your cycle. (4)

So putting it all together, specifically to how it impacts performance, among the hormonal forms of birth control, the IUD will have the least effect on performance followed by the progestin-only mini pill. According to Sims in The Contraceptive Conundrum, the IUD is a "localized dose of progestin, so you don't have systemic estrogen and progesterone like you get from oral contraceptives and other delivery methods like injections or patches" and the progestin-only mini pill has "fewer side effects and will be less likely to disrupt your training gains than a combined oral contraceptive pill." (5)

You don't need to be an Olympic athlete to want to have improvements to your fitness and maximize your training. You don't need to be a professional athlete to want to push past plateaus and test your limits. Knowing how hormonal birth control can both benefit and be disadvantageous to your fitness is part of that.

Resources

1. This Podcast Will Kill You, Episode 60, "Giving birth to "The Pill""
2. "Fuel for What You're Doing: Rethinking Fueling and Hydration with Dr. Stacy Sims" - Runners Connect Podcast
3. "Optimize Your Training Based On Your Gender" - BibRave Podcast Episode #105
4. "Stacy Sims: Women Are Not Small Men"  - The Curious Climber Podcast
5. "The Contraceptive Conundrum" blog post by Dr. Stacy Sims"Battle of the Hormones - Gender Specific Training"  - BibRave Podcast Episode #194

Interested in Working With a Coach Who Can Plan and Work With Your Hormones?

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Coach.n.fischer@gmail.com