A Masterclass in Improving Your HRV - Dr Jay Wiles
Heart rate variability (HRV) isn't about achieving the highest number—it's about stability over time. Your nervous system's adaptability matters more than any single reading. The key insight: train your nervous system to handle stress through real-time biofeedback, not by obsessing over daily scores
2h 9mKey Takeaway
Heart rate variability (HRV) isn't about achieving the highest number—it's about stability over time. Your nervous system's adaptability matters more than any single reading. The key insight: train your nervous system to handle stress through real-time biofeedback, not by obsessing over daily scores. Focus on reducing the day-to-day variation in your HRV (HRV CV - coefficient of variation) rather than chasing arbitrary targets.
Episode Overview
This episode provides a comprehensive deep-dive into heart rate variability (HRV), explaining what it actually measures, common misconceptions, and how to use it effectively. The discussion covers the autonomic nervous system, the difference between sympathetic and parasympathetic responses, why HRV varies between individuals, and practical applications for improving nervous system resilience. Key topics include non-modifiable factors (age, genetics, sex differences) versus modifiable factors (cardiorespiratory fitness, stress management, chronic health conditions), and why comparing your HRV to others is misleading.
Key Insights
HRV Measures Nervous System Adaptability, Not Stress Levels
HRV is the single greatest non-invasive proxy for measuring nervous system adaptations. It shows how well your nervous system responds and adapts to changing conditions, not how stressed you are at any given moment. Think of it as measuring adaptation, resilience, and flexibility rather than a direct stress reading.
Your Baseline Matters More Than Absolute Numbers
A 'good' HRV is actually a normal HRV for you—one that remains stable over time. Comparing your 50ms reading to someone's 150ms is meaningless. What matters is your trend: is your HRV stable, improving relative to your baseline, or declining? High HRV is only good when it's relative to your personal baseline.
Focus on HRV Coefficient of Variation (HRV CV)
Instead of obsessing over daily absolute HRV scores, track how much your HRV varies from day to day across a 7-day window. Lower day-to-day variation indicates a resilient nervous system that rebounds consistently. High variation suggests your system is struggling to adapt to stress, overtraining, or other demands.
The Heart Doesn't Beat Like a Metronome
When you see a heart rate of 60 BPM, your heart isn't beating exactly once per second. It's speeding up and slowing down constantly (speeding up on inhale, slowing on exhale). This variance between heartbeats, measured in milliseconds, reflects your nervous system making fine-tune adjustments to maintain homeostasis.
Age and Genetics Are Non-Modifiable, But Not Limiting
HRV naturally declines with age (especially after mid-30s to 40s) due to autonomic efficiency reduction and vascular stiffening. Genetics also play a significant role—some people are born with higher HRV. However, the ceiling for HRV isn't reduced by age, meaning you can still improve it through interventions regardless of your starting point.
Notable Quotes
"HRV is the single greatest non-invasive proxy that we have for measuring the adaptations of the nervous system."
"A good HRV is actually a normal HRV. It is a HRV that doesn't change across time very much. So, it's actually one that remains stable."
"High HRV is good, but it's only good when it's relative to you. It's not good when we're saying, 'Hey, I want to compare my HRV to someone else.' That's actually where we can get into trouble."
"When we look at HRV and say like, so for instance, if I put a strap on you and I said, 'Okay, let's measure Chris's HRV right now.' And it's a singular reading... What could I tell you about your stress response? The answer is I could tell you basically nothing."
"HRV is showing me how well you adapt to stress, how flexible you are to stress. Not how stressed you are, but how adaptable to stress you are. There's nuance there."
Action Items
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1
Track HRV Stability, Not Absolute Values
Instead of aiming for the highest HRV number, monitor how consistent your HRV is from day to day. Calculate your HRV coefficient of variation (HRV CV) by looking at how much your readings fluctuate over a 7-day window. Lower variation indicates better nervous system resilience.
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2
Improve Cardiorespiratory Fitness
Focus on increasing your VO2 max through cardiovascular training. As your fitness improves, your resting heart rate will decrease and stroke volume will increase, which typically leads to HRV improvements. Don't make HRV the goal—make fitness the goal, and HRV improvement will follow as a byproduct.
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3
Manage Overall Stress Load
Chronic stress buildup creates a rigid, less adaptive nervous system. Work on developing better adaptability to internal and external stressors through stress management techniques. The goal is to prevent your nervous system from being in a constant state of high alert, scanning for threats.
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4
Use HRV in Context, Not Isolation
Never make decisions based on a single HRV reading. Instead, track trends over time and use HRV in combination with other metrics (sleep quality, subjective feelings, performance data). Context is everything—one low reading doesn't mean you're doomed.