60 Seconds PPG Measurements - Tools & Best Practices

Heart Rate Variability Tools & Best Practices for

60 Seconds PPG Measurements

Marco Altini @marco_alt


•  Quick snapshot of your physiology (HR+HRV) – Parasympathetic activity

•  Low barrier (fast, convenient, no sensors)

•  Insightful – day to day variability due to external stressors

(training, travel, etc.), long term baseline changes (burnout?)

–  If done properly!

2012 - 2015

Tools/Technology


HRV4Training Camera HRV

2012 - 2015

Best Practices

Best Practices for 60 seconds PPG Measurements

•  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 /

clinical studies – Don’t read your email before the

measurement!

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 the measurement – 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

minute typically)



Consistency!

•  Choose: – A body position – A paced breathing rate – Waking time (more or less) / measurement

routine

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

Questions?

HRV4Training.com/faq.html

@marco_alt