The use of oral contraceptives and their effects on performance are an important and under-researched topic, so learning about this new meta-analysis on the subject we were really interested to dig into the findings.
According to research by the Guardian, the contraceptive pill was by far the most popular prescribed contraceptive in England in 2019, with nine in 10 women being prescribed this form of contraception.
In the US, around 14% of women aged between 15 and 49 are currently using the pill according to the CDC. Further, a 2020 study published in the International Journal of Sports Physiology and Performance found that over half (57%) of Elite female athletes in Denmark use hormonal contraceptives.
The oral contraceptive pill is popular among athletes because it:
- Eliminates unpredictable menstruation
- Has the ability to omit bleeding entirely
- Can be used strategically to manipulate the timing of periods, which can be beneficial during the competitive season
Yet despite its popularity, the effects of the oral contraceptive pill on exercise performance are still poorly understood.
Menstrual cycles can play a huge role on sports – not only on performance but participation as well – with many athletes altering or missing their training sessions altogether because of negative symptoms associated with their cycles.
If you’ve not done the maths already, this is at least a handful of days of training every month.
Authored by Elliott-Sale et al. and published in Sports medicine in 2020, the systematic literature review found 972 potentially relevant studies, of which 42 met the inclusion criteria and were used for the meta-analysis (a total of 590 participants were included). The quality of most studies was “moderate”.
The study, which is free to read online here, found that oral contraceptives do negatively affect performance on a population level, but whether female athletes should decide to take them or not ultimately comes down to an individual level.
Because this average effect was so small, current evidence doesn’t support general guidelines on the use or non-use of the pill.
The most useful way to visualise the results of the study is this graph:
Each row represents a study, with the width and height of each grey “hill” representing how much variation there was between study subjects and the study’s value. The steeper the hill, the more confidence there is in the results.
The further to the right of the dotted line, the bigger the negative effect of taking the pill.
On average, the results of most studies favoured naturally menstruating women, but the variation is huge and the effect small. Any study that crosses the central dotted line is regarded as statistically insignificant.
This means that only one study is confident that taking the pill has a negative effect on performance. 18 agree but aren’t conclusive. Two found no effect and three slightly favoured taking the pill, but again these weren’t significant.
The slight performance advantage found in the results falls in line with the Danish study I mentioned earlier, which found that positive physical symptoms were experienced more often by elite athletes who were not on hormonal contraceptives.
While in general there does seem to be a small performance disadvantage for athletes on the pill, the difference on average is barely significant.
Additionally, the authors noted that there was incredibly high variability between studies, with wide ranges between sports, age of athletes, and competitive levels, as well as research design and performance measured.
If female athletes want to prioritise performance over everything else, they’re better off experimenting with the use or non-use of the contraceptive pill to find out what works for them, taking medical, health, and personal reasons into consideration.
The thing is, while taking the contraceptive pill can help with painful and heavy periods as well as premenstrual syndrome, it can also come with many side-effects ranging from emotional symptoms such as mood swings, to physical symptoms such as headaches or dizziness.
The sport you practice, age, and performance level can all affect menstrual cycles.
Oversimplifying things, a track cyclist might find that she can’t train as hard when on the pill or her recovery takes longer. Conversely, a swimmer with a heavy period might miss training days each month on a natural period cycle, however, taking the pill might enable her to train on those extra days each month, even though the pill can come with slight negative physiological effects.
Ultimately, the primary reason why female athletes take the pill in the first place is for contraception – prime athletic years also generally fall in line with your menstruating years.
So, we conclude where we started, with relatively little new information but a good place to start. Individual athletes should not worry about the results of the meta-analysis and instead decide on whether to take or stop taking the oral contraceptive pill based on their individual requirements and response.
image sources
- effects-of-contraceptive-pill-on-sporting-performance: dusan jovic on Unsplash
