Ever wonder what stress or anxiety look like in your body? Your heart’s activity reflects both physical and mental stress, which is why heart rate variability (HRV) is an effective indicator of how much your system is leaning towards a stress vs. rest response.

Your Heart Under Stress

Your autonomic nervous system (ANS) regulates your heart. Under calm conditions, the rest-and-digest side of your ANS is constantly inhibiting the half that controls fight-or-flight. When stress kicks in, it eases up on the brakes, allowing the fight-or-flight system to accelerate and prepare your body to respond to stressors.

Your fight-or-flight system helps reallocate resources to prepare your body for action. Think of it as your ANS adding resources in some places (e.g., your muscles) while conserving them in other places (e.g., your digestion) when faced with danger.

Within your heart, your fight-or-flight system encourages your heart to beat more consistently, like a metronome, so your ANS can reallocate energy elsewhere.  Its activation speeds up your heart rate but decreases the variability between beats (your HRV).

In contrast, your rest-and-digest system uses resources to maintain your body’s functions. Its activation drops your overall heart rate and increases your HRV. When your heart doesn’t need to beat fast in order to pump blood to your muscles, it can be more flexible and vary between beats.

In short, stress decreases HRV, while rest increases it.

Patterns to Pay Attention To

A consistent pattern of physical and mental stress puts you at risk of injury, sickness, and long-term fatigue. HRV is a tool that can help warn you of an imbalance between activity and recovery.

In general, higher HRV is an indicator of better health and autonomic balance between your activation and rest systems. If you notice that your HRV is consistently low relative to your personal baseline, it’s likely that your fight-or-flight system is in overdrive and pushing your body at an unsustainable pace. You are taxed mentally, emotionally, hormonally, or physically.

On days when your HRV is low or you feel stressed or anxious, experiment with ways you can shift the balance back to rest or consider keeping track of common daily stressors.

Tips for Stress Management

We’ve all searched for the cure to stress in different places—a late-night delivery menu, a glass of wine, or the distraction of our social media newsfeed—anywhere but ourselves.

Start where the stress begins and get to know your body better. Put your insights into practice, and make your stress a thing of the past.

You can start by learning more about these activities that decrease stress and increase your HRV:

  • breathing techniques
  • meditation or mindfulness
  • massage therapy
  • time in nature
  • yoga
  • blue light blockers
  • pleasurable hobbies
  • increased fitness
  • epsom salt float tanks

References

  • Kim, Hye-Geum, Eun-Jin Cheon, Dai-Seg Bai, Young Hwan Lee, and Bon-Hoon Koo. “Stress and heart rate variability: A meta-analysis and review of the literature.” Psychiatry investigation 15, no. 3 (2018): 235. (link)
  • Litscher, Daniela, Lu Wang, Ingrid Gaischek, and Gerhard Litscher. “The influence of new colored light stimulation methods on heart rate variability, temperature, and well-being: results of a pilot study in humans.” Evidence-Based Complementary and Alternative Medicine 2013 (2013). (link)