How to session on Heart Rate Variability - Quantified Self Europe 2015

Heart Rate Variability What? Why? How?

Marco Altini, Paul LaFontaine @marco_alt @QuantSelfLaFont

BSc MSc Computer Science Engineering. PhD (in progress) Applied Machine Learning Head of Data Science - Bloom Technologies Self-Experimenter Maker all things HRV (HRV4Training, Camera HRV, HRV Logger)

Marco Altini - @marco_alt

Degree in Ops Research (Military Analytics) before computers Tracked 1700 negotiation discussions in Europe & Middle East Quantified Selfer, blogger, HRV & Blood Glucose enthusiast

Paul LaFontaine - @QuantSelfLaFont

2012 - 2015

Heart Rate Variability

Autonomic Nervous System

•  Sympathetic / Parasympathetic branches

•  How do we react to stressors? – Social / Environmental – Physical activity – Psychological stress – Health conditions

Beat to Beat Variation

2012 - 2015

What? Types of measurement

Types of measurement

Tools & Best Practices

•  60 seconds PPG measurements: day to day variability due to external stressors (training, travel, etc.), long term baseline changes (burnout?)

•  Situational readings: acute stressors, timing of fight/flight, planning factors

60 Seconds PPG Measurements

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

•  Low barrier (fast, convenient, no sensors)

•  Insightful –  If done properly!

Situational Readings

•  Indicator of when I go into fight/flight in meetings with others – Parasympathetic activity

•  More Preparation (needs heart rate belt)

•  Insightful – Measurements can show stress moments

2012 - 2015

Why?

Insights

Stress / Burnout prevention

More work ours, but in the zone, reflect in higher baseline HRV (good stress)

Low productivity or burnout, shows

lower HRV

Highly Productive

> 4 hours/day

Highly Productive

< 4 hours/day

Base

line

rMSS

D

Baseline HRV and High Productivity

Training load and recovery A year of data, day to day

differences all over the place (many factors influencing them) After average intensity or

intense training, consistently reduced

Jet-lag and physiological adaptations

HRV HR

1-2 days after traveling Week before

traveling

Week after traveling

Sick days and physiological recovery

HRV HR

1-2 days after getting sick Week before

getting sick

Week after onset

Spot checks: responses to acute stressors

-  Spot checks: responses to acute stressors

exercise breathing coffee

TIME OF DAY

Situational Readings (1/1)

Mee#ng  on  right  was  10  minutes  a3er  mee#ng  on  le3  

Situational Readings (2/3)

Dual  2  Back  Dual  3  Back  

Legend  

Situational Readings (3/3)

2012 - 2015

How? •  Tools/Technology •  Best Practices

2012 - 2015

Tools/Technology

60 Seconds PPG Measurements

•  PPG works, but very few PPG devices can be used for HRV

•  Do your homework on the technology you use (validated against ECGs or Polar’s)

•  Or use a Polar J

60 Seconds PPG Measurements

•  Some tools I made:

HRV4Training Camera HRV

•  Can measure discreetly

•  Useful in meetings

•  Assured accuracy

•  Learn to put on quickly!

HR Belt

Situational Readings

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)

Paced Breathing (2/3)

Paced Breathing (3/3)

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

Best Practices for Situational Readings

•  When to take the measurement

–  Day part makes a difference (morning, afternoon)

•  What type of measurement –  Posture control (sitting)

•  Paced breathing –  When you talk vs. when they talk

•  What metric to use?

–  RR intervals snapshot vs. rMSSD

•  Change Readings: Listen vs. Talk

Time  of  Day  

Length  of  Reading  

Food  &  Water  

Control Effects That Alter Readings

Paced Breath Example

Questions?

HRV4Training.com/faq.html QuantSelfLaFont.com QuantXLaFont.com

@marco_alt

@QuantSelfLaFont