60 Seconds PPG Measurements - Tools & Best Practices
Heart Rate Variability
Tools & Best Practices for
60 Seconds PPG
60 Seconds PPG Measurements
• Quick snapshot of your physiology (HR
– Parasympathetic activity
• Low barrier (fast, convenient, no sensors)
– day to day variability due to external stressors
(training, travel, etc.), long term baseline
– If done properly!
Best Practices for 60 seconds
• When to take the measurement
– Morning, during the day?, etc.
• What type of measurement
– Lying down, sitting, orthostatic?
• Paced breathing
– Constrained, unconstrained?
• What metric to use?
– Time domain, frequency domain?
• Are 60 seconds really enough?
When to take the measurement
• First thing after waking up
– Relaxed physiological state
– Limit all external stressors
– Closest to what we do in research /
– Don’t read your email before the
What type of measurement
• Lying down while still in bed
– Limits other factors like not waiting
enough after standing up
– Performed in clinical studies
– Sitting/Standing also valid, however for
simplicity I’d recommend lying down
Paced Breathing (1/3)
• Improves reliability and repeatability of
– Breathing patterns and RSA have an
impact on HRV values
– Using paced breathing provides more
consistent settings (same context!)
– Use what works for you (8-12 breaths per
– A body position
– A paced breathing rate
– Waking time (more or less) / measurement
Stick to those
What metric to use?
• HRV is not a single number
• Use rMSSD or ln rMSSD
– Marker of parasympathetic activity (only
thing you can reliably measure). There is
no clear sympathetic marker
– HF, LF, HF/LF or other frequency domain
features require more time (and are
computed differently by everyone,
difficult to generalize/compare)
Are 60 seconds really enough?
• Yes. Just follow the best practices