Garmin measures stress primarily through heart rate variability (HRV), which is the variation in time intervals between consecutive heartbeats. When you wear a Garmin device, it uses its optical heart rate sensor to monitor your pulse continuously, detecting the beat-to-beat intervals
. How Garmin Measures Stress:
- The device collects heart rate data and calculates HRV during periods of inactivity or rest to establish a baseline
- Garmin applies an algorithm from Firstbeat Analytics to analyze changes in HRV compared to this baseline. When HRV decreases (shorter intervals between beats), it indicates higher stress, while longer intervals suggest relaxation
- To avoid confusing physical activity with stress, Garmin ignores HRV data during exercise or active periods
- The watch combines HRV data with other biometric inputs such as sleep quality, activity levels, calories burned, and even user-input nutrition data to produce a comprehensive "Stress Score" on a scale from 0 (low stress) to 100 (high stress)
- Garmin also uses this data to calculate a "Body Battery" metric, reflecting your energy reserves by factoring in stress, activity, and rest
Additional Features:
- Some Garmin devices provide "Relax Reminders" that prompt you to take breaks when elevated stress levels persist
- Wearing the device consistently, including overnight, improves the accuracy of stress tracking by refining your personal baseline
Limitations:
- Garmin's stress measurement is an estimate, not a medical diagnostic tool
- Intense physical activity or environmental factors can sometimes be misinterpreted as stress
- The device indicates when you are stressed but does not identify the causes; users must correlate stress scores with life events themselves
In summary, Garmin measures stress by analyzing heart rate variability through its optical sensors, applying advanced algorithms to interpret physiological signals, and integrating multiple health metrics to provide a stress level score that helps users monitor and manage their stress over time
