I Was Sick for a Week: Here Are Six Health Changes My Apple Watch Detected.

Experiencing an illness like a cold or the flu is not only uncomfortable but also leads to measurable changes in the body. Last week, I faced several flu-related symptoms, and as I regained my health, I reviewed the health data that my Apple Watch Ultra 2 had collected during those days.

Although I don’t use the watch to track sleep, by examining other indicators, I noticed significant changes in my health metrics. Below, I summarize six ways my body was affected during my illness, according to the data recorded by my watch.

1. Heart Rate
   I started feeling unwell the day before my 30th birthday. I noticed a significant increase in my heart rate, even though I did not engage in intense exercise. My data shows that during the days I was ill, my heart rate rose, correlating with the severity of the symptoms I was experiencing.

2. Resting Heart Rate
   A clear relationship with the increase in heart rate was the rise in my resting heart rate. This indicator measures beats per minute while at rest, and an increase was observed from 60 bpm to 66 bpm during my recovery process.

3. Blood Oxygen Levels
   Although I usually approach blood oxygen readings from smartwatches with skepticism, my data showed a clear drop in oxygen levels in the days following my illness, coinciding with the rise in my heart rate.

4. Heart Rate Variability (HRV)
   HRV is used to assess training ability, and generally, an increase in this metric suggests better health. However, as I became ill, my HRV decreased, indicating a nervous system response to the illness.

5. Average Walking Heart Rate
   When I attempted to do sightseeing despite being sick, my average walking heart rate also showed an increase, reflecting a pattern aligned with both my resting heart rate and overall heart rate.

6. VO2 Max
   This metric, which measures cardiovascular fitness, was also affected. Despite not exercising during my illness, the Apple Health app recorded a drop in my VO2 Max, linked to changes in my heart rate and oxygen levels.

Reflecting on this data is interesting, especially considering how technology can track health changes. While the data is useful, I am unsure of its effectiveness in predicting illnesses. Sometimes, receiving alerts about poor sleep quality or the possibility of becoming ill can amplify the feeling of discomfort.

However, the ability of smartwatches to detect potential symptoms of illnesses is evident and could be valuable in more serious situations, where metrics can be crucial for personal health.