A lot of us have dabbled in the wearable health and fitness game – whether you’re determined to close those rings everyday or you wear one in the hope it’ll get you moving (GUILTY) we see them as a modern-day marvel that help us smash our goals.
But, as it turns out, only three per cent of sport science research is exclusively focussed on women – and hardly any wearable fitness trackers take your period or your menstrual cycle into account at all.
Women experience dramatic hormonal shifts throughout phases of the menstrual cycle that vary by individual, producing different physiological responses (ie ability to take on Strain, Sleep need) that have been previously poorly understood due to limited scientific research.
We spoke to Emily Capodilupo, VP of Data Science and Research at WHOOP (a wearable that actually does take into account what’s going on with your uterus) about the issue, and why tracking your cycle is so important for optimal results.
Because fitness is our passion, amirite?
Capsule: Why haven’t women’s menstrual cycles been incorporated into trackers and personal health technology previously and why is it important to do so?
Emily: I would guess primarily it’s due to a lack of education – when we surveyed our members late last year, only 9% of female-identifying members had been told by a doctor, coach or trainer that their menstrual cycle impacted their training. It’s so important to incorporate this information because when you train with your cycle you can progress faster and more safely. The mix of hormones in your body at a given moment determines if your body is going to be able to put on muscle, if your body prefers fat or carbs as a fuel source, and how much water your body will want to retain.
These hormones fluctuate with the menstrual cycle, so knowing which cycle phase you are in gives you valuable intel as to what your body needs to train most efficiently today. Beyond the science and the data though, it’s important for wearables and personal health technology to incorporate this information because representation is so important – those of us who have experienced a menstrual cycle know that we feel differently during different times of the month, so when our health tech acknowledges that in the recommendations it feels like it’s actually made for us.
How much does a menstrual cycle impact day-to-day life, and also people’s fitness and health journeys?
For athletes who understand and leverage their menstrual cycles, the impact can be very positive. Weirdly, during our periods (also known as the early Follicular Phase) even though many of us don’t feel like working out, we’re hormonally in a great place to perform. In her book, ROAR, Dr. Stacy Sims – who trains elite endurance athletes and is part of the WHOOP Women’s Performance Collective – mentions that you are disproportionately primed to perform during your period.
After ovulation, we tend to feel more lethargic and are hormonally less primed to perform – if you are aware of this pattern you can plan your training to have higher intensity workouts during the first half of your cycle and lower intensity workouts during the second half. This will leave you feeling better and improving faster than doing the opposite or training randomly throughout your cycle.
The vast majority of exercise physiology research excludes female subjects in order to avoid the menstrual cycle confounding the data. This means that nearly half of all people are training based on “best practices” that haven’t actually been proven to apply to them. This seems like such a reductive, and quite simply, sexist approach to data and research. Why has this been the case for so long when just as many women work out and keep fit as men?
A lot of it unfortunately comes down to a lack of funding – the more variables you have, the more subjects or data you need to collect to get statistical power (meaning confidence that your results are not a fluke). Research involving humans tends to be expensive, in terms of both time and dollars, so there is often pressure to get as little data as you can without sacrificing statistical power which requires controlling for as much as you can.
Unfortunately, this resulted in a complacency with eliminating sex and menstrual cycle phase as variables and focusing research on men. We’re really proud to be working to change this trend and that our menstrual cycle research and menstrual cycle coaching features are helping to close this gap both in how women train, and in the broader awareness that sex and menstrual cycle phase are important variables to understand and not just control for. One thing I’ve been really encouraged by is the amazing response from male-identifying members to our research and the release of those new features. As more practitioners and academics are aware of the importance of training with your menstrual cycle, it will be harder to get away with cutting corners by ignoring women in exercise physiology research.