Garmin Body Battery tracks physiological recovery via heart rate variability

Garmin’s Body Battery metric, introduced in 2018, measures physiological recovery rather than simple hours spent in bed. The feature uses a scale from 0 to 100 to indicate an individual's energy levels, functioning similarly to a smartphone battery indicator.

To calculate this value, the system analyzes data recorded by the wrist throughout the day and night, including heart rate, heart rate variability (HRV), stress levels, and physical activity. High HRV indicates the nervous system is in recovery mode, while low variability suggests tension.

Factors that can result in a low Body Battery score despite a full night of sleep include fragmented sleep, late meals, alcohol consumption, intense late-night exercise, or the onset of illness. The data is processed and accessible via the Garmin Connect app.