WHOOP Unveils Novel Digital Biomarker for Menstrual Cycle Monitoring in Nature Study

In a new study published in Nature’s Digital Medicine journal, WHOOP researchers have introduced a new digital biomarker for monitoring menstrual cycles through wearable technology. The study, analyzing over 45,000 menstrual cycles from 11,590 participants, represents one of the largest investigations into cardiovascular changes across menstrual cycles using wearable technology.

The research team developed a novel metric called “cardiovascular amplitude” that measures fluctuations in resting heart rate (RHR) and heart rate variability (RMSSD) throughout the menstrual cycle. This non-invasive measurement could potentially serve as an indicator of reproductive health and cycle irregularities.

“This work is a big leap forward in how we understand and monitor female physiology,” says Will Ahmed, WHOOP’s CEO. “It was previously well understood that several vital signs fluctuate with the phase of your menstrual cycle, but it was never before understood whether or not the extent of those fluctuations were significant and if so, what they might mean.”

Key findings from the study reveal that cardiovascular metrics follow a predictable pattern throughout the menstrual cycle, with population RHR reaching its lowest point and RMSSD peaking around day 5, followed by RHR maximums around day 26 and RMSSD minimums near day 27. Notably, the research showed that these cardiovascular fluctuations were significantly reduced in participants who were older, had higher BMI, or were using hormonal birth control.

The study leveraged WHOOP’s continuous monitoring capabilities, analyzing over 1.2 million days of biometric data. “This study was made possible by our always-on data and global scale,” Ahmed notes. “It utilized over 1 million days of WHOOP data, enabling insights that aren’t feasible without a 24/7 wearable.”

Lead researcher Summer R. Jasinski and team suggest that this new metric could serve as “an easily accessible and reliable indicator of female reproductive hormones across the menstrual cycle.” The findings are particularly significant given that current methods for hormone monitoring, such as urine and saliva testing, can be costly and burdensome.

Ahmed emphasizes WHOOP’s commitment to women’s health research: “Only 3% of medical research is focused on women. WHOOP is committed to investing equally in women’s and men’s health research.” The company plans to integrate these research findings into their product development to better serve their female users.

The research opens new possibilities for non-invasive monitoring of female reproductive health, potentially enabling earlier detection of cycle irregularities and reproductive health issues. As wearable technology continues to evolve, such digital biomarkers could play an increasingly important role in women’s healthcare monitoring and delivery.