Did you know that we have nearly 3.5 trillion clocks in our bodies that affect things like our organs, weight, sleep and fertility? Most of these clocks in our bodies function on a 24-hour cycle, and are referred to as circadian rhythms. Owing to the rotation of the earth around its own axis, plants and animals have evolved around a 24-hour light-dark cycle. Circadian rhythms are biochemical, physiological, and behavioral cycles that run on a 24-hour period thanks to the planet we evolved on. They are essential for our well-being and when the clocks are off, they have been linked to weight gain, sleep deprivation, and even diseases. Core temperature is the most reliable biomarker for circadian rhythm, meaning that if you can measure core temperature, then you can see patterns in your circadian rhythms and assess how your clocks are working (1).
Sixteen years ago, researcher Mary Coyne and her team confirmed that women’s menstrual and fertility cycles reliably tracked by continuous core body temperature (2). By measuring continuous core temperature, they found a distinct circadian rhythm that can detect the phases of a woman’s menstrual cycle and predict impending ovulation. They noticed that about 2 days before ovulation, there is a subtle dip in temperature. What this means is that if women could measure their core temperature continuously, they could predict impending ovulation and detect whether or not they ovulated with a 99% accuracy (2).
Learn more about how circadian rhythm can predict ovulation.
While there are sensors out on the market that measure temperature from your ear, mouth or wrist, core body temperature may prove to be more accurate. In fact, literature shows that using peripheral thermometers do not provide accurate readings and should not be used to influence clinical decisions (3). Dr. Wade Webster explains that skin peripheral temperature lacks correlation with core in most circumstances. As one begins to sweat, for example, skin temperature drops while core temperature begins to climb.
Here at Prima-Temp, we are working on building a mobile phone platform that measures core body temperature for predicting ovulation. To learn more about Priya click here.
- Brown et al. (2000). A statistical model of the human core-temperature circadian rhythm. Am J Physiol Endocrinol Metab 279: E669–E683.
- Coyne et al. (2000). Circadian Rhythm Changes in Core Temperature over the Menstrual Cycle: Method for Noninvasive Monitoring Physiol Regulatory Integrative Com Physiol. AM J 279:1316-132.
- Webster, W. https://www.linkedin.com/pulse/science-behind-priya-circadian-rhythm-part-4-wade-webster