Thank you Marg KJ, Robin White, The Wellspring Collaborative, Fiona M, and many others for tuning into my live video with Chris Miller MD!

In our latest live session, Chris Miller MD and I took a deep dive into one of the most powerful markers of health and longevity: Heart Rate Variability (HRV). I also announced the launch of The Habit Healer Live Lab, a new series where I’ll be walking through tiny healing habits around a particular subject, starting with hip mobility and strength, to show you how small, consistent changes lead to real healing using myself as the guinea pig. I will check in every few days and then compare day 1 with day 30 results. Should be fun! (I think.) Subscribe now so you don’t miss it.

What Exactly is HRV?

Most people know their resting heart rate (e.g., 60 beats per minute), but your heart doesn’t actually beat like a perfect metronome. There are millisecond differences between each beat. This “beat-to-beat” variability is called Heart Rate Variability (HRV).

HRV is controlled by your Autonomic Nervous System (ANS), specifically the Vagus Nerve.

* Sympathetic Nervous System: The “gas pedal” (fight or flight).

* Parasympathetic Nervous System: The “brake” (rest and digest).

A higher HRV generally means your body is resilient, recovered, and has a strong “parasympathetic tone.” It is linked to better longevity, fewer heart attacks, and less cognitive decline.

Read Dr. Chris’s Full Deep Dive: HRV: The Real-Time Measure of Inflammation, Resilience, and How Fast You’re Aging

Can You Actually Change Your HRV?

There is some debate here. Some cardiologists may tell you it’s fixed, and in certain medical contexts, they are right. Factors that can “lock” your HRV or make it harder to change include:

* Cardiac Ablations: Procedures for conditions like AFib can change the heart’s electrical system, making HRV appear low and static even if you are getting fitter.

* Medications: Certain drugs can dampen the variability.

* Age and Inflammation: HRV naturally trends downward as we age, and chronic inflammation (high cytokines) can keep it suppressed.

However, for most people, you can absolutely improve your HRV relative to your own baseline. It is a highly individualized metric, don’t compare your 40 to someone else’s 100!

7 Levers to Improve Your HRV

If you want to strengthen your Vagus nerve and improve your recovery, here are the most effective levers you can pull:

1. Targeted Breathwork

This is the fastest way to see a change. Dr. Chris recommends the 4-7-8 technique:

* Inhale for 4.

* Hold for 7.

* Exhale for 8. The long exhale triggers the parasympathetic nervous system to slow the heart down immediately.

2. Master Your Sleep

Sleep apnea, restless nights, and poor hygiene destroy HRV. Consistency is key—try to go to bed and wake up within 30 minutes of the same time every day to avoid “social jetlag.”

3. Strategic Exercise

Both resistance training and cardio improve autonomic tone. If you want to accelerate results, try vigorous intervals like the Norwegian 4x4.

How to do the Norwegian 4x4: The Science Shows Four Minutes Is the Perfect Dose to Heal the Heart.

4. Anti-Inflammatory Nutrition

Avoid ultra-processed foods (UPFs). A recent study showed that just five days of UPFs can cause metabolic dysregulation. Focus on the “colors of the rainbow” and plenty of fiber.

The Hidden Danger of Ultra-Processed Foods: What If Your Groceries Came With a Warning Label?

5. Cold and Heat Exposure (Hormesis)

Saunas and cold plunges act as “good stress.” They force the body to use both the gas pedal and the brake at the same time, eventually making the system more resilient.

Sauna deep-dive: The 20-Minute Ritual That Protects Your Heart Like ExerciseCold water immersion series

6. Social Connection

This is the most underrated lever. Spending the day isolated at a computer can lower HRV. Getting out, laughing, and connecting with friends has a measurable positive impact on your heart’s rhythm.

7. Sense of Purpose

Having a reason to wake up, whether it’s family, a hobby, or a career, helps keep the nervous system in a state of healthy engagement rather than chronic stress.

A Word on Obsession

While data is empowering, don’t let the numbers stress you out. If checking your wearable at 2:00 AM causes anxiety, it’s counterproductive! Use HRV as a compass, not a grade. Look at the trends over weeks and months rather than stressing over a single night’s score.

Get full access to The Habit Healers at drlauriemarbas.substack.com/subscribe