Alignment Between Heart Rate Variability From Fitness Trackers and Perceived Stress: Perspectives From a Large-Scale...

Area of Science:

• Physiological monitoring
• Psychophysiology
• Wearable technology

Background:

• Stress negatively impacts health and well-being.
• Laboratory studies show decreased heart rate variability (HRV) during induced stress.
• Wearable devices are increasingly used to monitor perceived stress via HRV in real-world settings, but validation is needed.

Purpose of the Study:

• To quantify the association between HRV and perceived daily stress using wearable devices in naturalistic settings.
• To determine if established lab findings on stress and HRV replicate outside the lab.

Main Methods:

• 657 participants wore fitness trackers and completed 14,695 ecological momentary assessments (EMAs) over 8 weeks.
• A follow-up study with 327 participants assessed perceived stress over 1 week.
• Mixed-effects generalized linear models predicted EMA responses from HRV features across various time windows.

Main Results:

• Models explained only a small average of 1% of the variance in perceived stress.
• HRV features from work hours (8 AM to 6 PM) showed slightly better prediction (2.2%) than other windows.
• Specific HRV metrics like LF/HF ratio and VLF power were associated with perceived stress, anxiety, and affect.

Conclusions:

• A statistically significant but weak relationship exists between perceived stress and HRV in real-world settings.
• The association between HRV and perceived stress is weaker in naturalistic settings compared to laboratory conditions.
• Wearable-derived HRV alone is insufficient for accurately detecting stress in daily life; it's a component of a complex phenomenon.