Buzz
The Apple Watch S8 boasts the ability to measure wrist skin temperature using its new body temperature sensor. This marks one of the most significant upgrades in the S8 generation. Moreover, this new feature is primarily designed for tracking menstrual cycles, perhaps offering value mainly for women. Hence, I am quite excited to experience the new Apple smartwatch, starting from the Apple Watch S3.
Towards the end of last year, I had a post demonstrating that after many years, the Apple Watch has improved its battery life. At least, it can last more than 1 day for my communication and connection maintenance needs.
Centering around the ability to track and predict menstrual cycles in the new Apple Watch S8, this is what captures my interest.
How does the wrist temperature sensor work?
In theory, when wearing the Apple Watch S8 to sleep every night, the device will sample wrist temperature every 5 seconds. Initially, users need to wear it for 5 consecutive nights for the Apple Watch to adapt and record data. Afterward, the watch will capture data every night.
By analyzing body temperature changes, the smartwatch will provide insights into ovulation time and predict the next menstrual cycle or fertility window.Wearing the Apple Watch S8 consistently during sleep will generate a wrist temperature data chart in the Health app. It illustrates how an individual's body temperature varies each night compared to the baseline (average value of recent measurements).Misconception about predicting menstrual cycles based on wrist temperature changes
In reality, the menstrual cycle tracking feature on Apple Watch S8 operates similarly to its predecessors rather than being excessively revolutionary. What sets it apart is the addition of specialized sensors, enabling more accurate health data measurements and consequently more precise predictions.Essentially, it relies on initial health data provided by users, such as cycle length, recent menstrual history, etc. Utilizing this information, combined with temperature sensor readings, enhances the tracking and forecasting capabilities for subsequent cycles. Predictions will be issued at the beginning of the month, evolving and improving as the months progress.
The prediction schedule will not self-adjust within the same month.Why the Body Temperature Sensor Loses Effectiveness After the Initial Month of Use
The Apple Watch is simply an electronic device, a health monitoring assistant. Any abnormal findings from Apple must be verified through medical facilities or consultation with specialized doctors. Apple emphasizes this point. As an electronic device relying on sensors, the Apple Watch S8 requires time to receive and refine data for optimal functionality. Following Apple's recommendation, users need to wear it continuously for the first 5 days to initiate data reception. Subsequently, wearing it consistently for 2 months allows the device to accumulate sufficient data. Only through a comprehensive dataset can the system provide the most accurate analyses.
Optimal Conditions for Efficient Menstrual Cycle Tracking Feature
There are three essential considerations for accurately measuring wrist temperature and tracking menstrual cycles:
- Users must wear the watch during sleep because it performs measurements at night.
- The watch must have Sleep Focus mode enabled every night.
- Maintain continuous watch-wearing during sleep, minimizing interruptions. Avoid wearing it for a few days and then removing it for a few days. This intermittent use disrupts the watch's data continuity, affecting the accuracy of predictions.
Revisiting the Experience After 5 Months of Continuous Wear
I'll break it down into 3 phases, as these stages have evolved significantly since the initial wearing period.First 2 Months
As mentioned earlier, the initial 2 months are primarily focused on data collection for the Apple Watch. Consequently, the system may not provide the most accurate predictions during this period.
My experience in the first 2 months revealed inaccurate predictions, with forecasted dates deviating significantly from reality (over 1 week difference).Following Month
Stepping into the third month, I gradually recognized the utility of the menstrual cycle prediction feature on the Apple Watch S8. The watch began issuing notifications several days before the 'red alert' days.
During this period, my body also exhibited warning signs of the upcoming menstrual cycle. Women often intuitively sense bodily irregularities as an impending signal. Correspondingly on the watch, these days were marked with a light red hue.Recent 2 Months
In these recent 2 months, I consistently received menstrual cycle notifications closely aligning with reality. Comparing the deeply red-highlighted days on the system, the actual menstrual cycle was practically just 1 day away, and very accurately so. These are the days when I experience intense abdominal pain and complete fatigue— the most exhausting and dreadful days I go through every month.
Certainly, the watch will find it challenging to pinpoint the exact day of ovulation for women with 100% accuracy. It provides relative predictions to help us prepare our bodies better through adequate nutrition, sufficient sleep, and lighter physical activity to avoid fatigue.
