Aiming to optimize your athletic performance? Think about your contraception choice.
For all gym gals, female athletes, reformer fans, Barry’s enthusiasts, marathon runners and anyone thinking about picking up exercise, this one's for you.
Did you know that hormonal changes during the menstrual cycle impact your athletic performance? And that your contraception choice may impact it as well?
Hormones and athletic performance
Hormones play a crucial role in our overall health. Female sex hormones (estrogen, progesterone, testosterone) also play a huge role in our overall health and numerous physiological processes making the name ‘sex hormones’ rather reductive. They impact our metabolism, heart rate variability, appetite, mood, cognition, bone health, body temperature, pain sensation, generating muscle force and much more… inevitably impacting our athletic performance.
Performance optimization
Let’s say your goal for 2024 is to win a gold medal during the Olympics. Or something more realistic like a 100kg hip-thrust. What will you do to achieve this goal? You will keep training hip thrusts with increasing weight. You’ll make sure you get enough rest between your gym sessions. You will sleep well. You will eat well and make sure you get enough protein. You may try to optimize with some supplements. But what about your contraception choice? Is your contraceptive method moving you in the right direction? Or should you come off contraception and start cycle-syncing1 instead?
Cycle-syncing and performance
Let’s start by looking at what happens to your athletic performance when you are not on hormonal birth control and ovulating and cycling naturally.
Females can absolutely perform at any point in their menstrual cycle. However, our athletic performance may fluctuate during the cycle as the cyclical changes affect various processes in our body related to exercise such as energy levels and strength. The extent to which these hormonal fluctuations affect us varies widely. Some of us are more susceptible to being affected by hormonal changes during the cycle than others.
Here’s an overview of the potential impacts of cyclical hormonal changes on female athletic performance (refer to the graph above for the phases and hormones):
1. Early Follicular Phase - period
The first day of your period is the first day of your cycle and marks the start of the follicular phase. This is when both estrogen and progesterone are low. If you are anything like me, this is when your exercise performance is at an all-time low. On the first day of my period - I’m out. I power through my day but there’s no way I’ll get myself to the gym. For people with endometriosis, adenomyosis or menorrhagia periods can be associated with overwhelming fatigue, cramps, sickness and feeling faint. Exercise can release endorphins which are natural painkillers so if you can, light exercise (yoga, pilates, walking etc) is the way to go on during this phase.
2. Mid-Follicular Phase
As your estrogen starts to rise, you are transitioning into your strongest and most optimal phase when it comes to athletic performance. Estrogen is making you feel better, stronger and more motivated. Higher estrogen levels can enhance muscle glycogen storage and utilization, potentially improving endurance and energy. We have more capacity to deal with stress, including an intense workout. Great time to lift, go for a HIIT class or fast2. Now it’s the time to aim for your personal best, hit that highest speed on the treadmill and increase your weights.
3. Ovulation
This is when some of us will feel best in terms of mood, energy and performance. However, there’s some interesting research that found that female athletes are more likely to suffer knee joint injuries during this time (1). This is thought to be related to the estrogen-induced laxity of the ACL3, which compromises knee stability during high-impact activities.
4. Luteal phase
The luteal phase is dominated by progesterone. Compared to the follicular phase, you may feel more fatigued and sleep less deeply - decreasing your performance and strength. Our hormones are dropping in this phase which means premenstrual syndrome and symptoms (PMS) for some of us such as bloating, mood swings, and fatigue. If you are affected by this change, the luteal phase is your yoga and pilates phase.
TL;DR If you are aiming to optimize your athletic performance when cycling naturally, your best bet is to get to know your own patterns and optimize your fitness routine accordingly. To do that, start by tracking your cycle and noticing if you experience any of these trends and hormonal fluctuations. You may actually feel great on your periods and not experience any PMS and hence may not have a reason to slow down or change how you exercise. You can always experiment to see if adjusting your exercise to your cycle makes any difference for you. There’s an app called WILD.AI that is helping women adjust their exercise routine to their cycle.
Contraception and athletic performance
There are many types of contraceptive methods - some of them do not affect your hormonal baseline while others do. Most research done on the topic of contraception and athletic performance looked at the combined oral contraceptive pill (COCP), so let’s talk about that.
Using hormonal contraception can give you more control and predictability in terms of your athletic performance. Many women use hormonal contraceptives to decrease their menstrual flow and pain or even stop periods completely. Many use contraception to manage unpleasant menstrual and luteal symptoms (cramps, bloating, PMS etc). Being on a contraceptive method can lead to more consistent training and performance as you are not dealing with your cyclical fluctuations.
However, not everyone will get along well with hormonal contraception. Some of us develop side effects which could negatively impact our athletic performance. For example, you may experience mood changes which will impact your motivation or experience water retention which can lead to an increase in weight.
What about the direct impact of contraception on the physiological changes related to athletic performance?
Unfortunately, the question remains largely unanswered as the research on the effects of contraception on exercise performance is not conclusive just yet. On one hand, some studies suggest that COCP may reduce the risk of certain injuries, such as ACL tears, due to the stabilization of hormone levels. On the other hand, some suggest that being on COCP leads to higher cortisol, lower testosterone and a slight decrease in VO2 max. The findings are often conflicting or show minimal effects which are not enough to make practical, generalized recommendations. The summary of all this research was published in a meta-analysis in 2020 concluding that:
“COCP use might result in slightly inferior exercise performance on average when compared to naturally menstruating women ''. However, researchers continue to explain that “Practically, as effects tended to be trivial and variable across studies, the current evidence does not warrant general guidance on using or not using COCPs (2)”.
More research is required to understand the difference between various formulations of COCP and different types of contraceptives. For example, what about the impact of Copper IUD, LNG IUD, implant, POPs on athletic performance? When researching this topic I came across a brilliantly named publication called “Where is the data” (3). Researchers attempted to analyze the impact of LNG IUD on athletic performance - the amount of eligible studies to include in their analysis was precisely ‘0’ - what a sad representation of the state of women’s health research (see figure below).
Importantly, individual responses to contraceptives differ significantly, making general recommendations challenging. Some individuals might experience no performance-related side effects, whereas others might experience quite substantial ones.
In conclusion, as of July 2024, we don’t have enough robust data to make generalized recommendations on contraception and athletic performance. Tracking how you are feeling is the way to go here as well.
Professional female athletes
The question of contraception and athletic performance is even more important to professional athletes. For those, the smallest, marginal change could make a difference.
According to the British Sportswomen Study, many female athletes report using the COCP strategically to control the impact their periods have on their performance. They can time their bleeding or take the pill continuously so that it does not interfere with training or competition. Having the means to alleviate monthly cramps, bloating and headaches can enable more training and improved performance. Moreover, the option to eliminate or emit menstruation can remove a big uncertainty risk factor, especially for sports events.
On the other hand, a benefit of having a natural hormonal cycle is being able to use it as your ‘vital sign’ just as your pulse, temperature, respiration rate, and blood pressure. Your menstrual cycle provides you with information about your health. For example, changes to menstruation like amenorrhea or oligomenorrhoea could signal that the athlete is overtraining or undereating. Moreover, female athletes who are on hormonal contraception may be missing out on the ‘performance boost’ we naturally get from estrogen in that mid-follicular phase of the cycle as described above.
“If you look at elite level, medals have been won on every day of the menstrual cycle, medals have been won by pill users”, according to Professor Elliott-Sale, an expert in this field.
Given that at the elite level, the differences between winning and losing are so minimal, I think we need more answers. The inclusion of women and girls in sports medicine and exercise science research is extremely poor. Of articles published in learning sports journals from 2014 to 2020, only 6% exclusively studied women (4). 6%! Luckily, Professor Elliott-Sale also thinks women deserve more answers and she’s launched an international, multisite project to address the lack of sufficiently powered, high-quality studies on the impact of menstruation and contraception on sports performance in female athletes (5).
Conclusions
As we wait for the results of this exciting study, beyond optimizing nutrition, sleep, supplements and training, there are two main options for optimizing female hormones for athletic performance:
Cycling naturally which may come with fluctuating performance and bothersome periods but you are not risking potential side effects from hormonal contraception. This may be more optimal if your periods are not bothersome, regular and predictable.
Using hormonal contraception which may come with side effects but can offer predictability and control over your periods. It may take a bit of trial and error to find the one that suits you and is not causing you side effects but this may be worthwhile if you are dealing with challenging menstrual periods, symptoms and fluctuations.
There’s no right or wrong - it’s all about what matters to you and your circumstances. I’m far from being a professional athlete but I imagine that the decision also depends on the specific sport you are trying to optimize for.
For athletes and beginners, it may be worth experimenting with tracking your symptoms without contraception first to see if you are sensitive to hormonal fluctuations or not. Track how you are feeling and performing. It’s also a good time to assess your hormonal health and make sure there are no underlying issues (eg. PCOS). Once you know what your baseline is, you can decide how to best 'optimize/biohack it’ for your goal. If you decide to try a hormonal contraceptive method, monitor your symptoms and performance and adjust if you are experiencing side effects.
References:
1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7956981/
2. https://pubmed.ncbi.nlm.nih.gov/32666247/
3. https://hfjc.library.ubc.ca/index.php/HFJC/article/view/308/322
4. https://bjsm.bmj.com/content/early/2024/07/09/bjsports-2023-107886
5. https://bmjopensem.bmj.com/content/9/4/e001814
Cycle syncing involves being aware of the different phases of your menstrual cycle, and adjusting your lifestyle, such as diet and exercise to support your body during each phase.
The impact of fasting on female health and exercise is a topic for another article. Studies on female rats showed that prolonged fasting led to hormone dysfunction and stress, indicating that women might need to be more cautious with extended fasting periods.
The anterior cruciate ligament (ACL) is one of the key ligaments that help stabilize the knee joint.