On Stress, Glucose and Heart Rate Variability (HRV)

Blog post by Marco Altini

​How does the body respond to stress?

Below I look at heart rate variability (HRV), heart rate, and glucose in response to two very different weeks (N = 1).

High vs low stress:

• 42% decrease in HRV
• 9% increase in resting heart rate
• 13% increase in 24h average glucose

Some context first

Last summer in July I had a strong negative stress response (cumulative stressors), resulting in arrhythmia and concerns for my health I've talked about this before, but here I want to focus on what happened to glucose during that week.

Coincidentally, I was wearing a continuous glucose monitor (CGM) since the previous week and noticed that after meals, my glucose was spiking really high, near 200 mg/dL, consistently.

Very interesting to see poor regulation at work so clearly.

As usual, I was also monitoring my resting physiology (HRV and HR) using HRV4Training (morning measurements), and saw quite a dip in HRV, as well as a minor change in heart rate This is the type of stress response I often discuss (see for example my guide here).

​Physiologically, we know that high stress is associated acutely and chronically with elevated glucose in the bloodstream and reduced parasympathetic activity Pretty neat to see it with simple measurements and currently available technology.