What Your Heart Could Reveal About Stress and Health
By Jamie Bussin, featuring David Nelson
What if there were an easily tracked metric that could offer insight into potential current or future health problems, including heart conditions, anxiety, depression and other mental health concerns? You’d probably want to know a little more.
Heart rate variability (HRV) can be tracked relatively easily using smartwatch and smartphone technology. According to my guest, health and wellness researcher David Nelson, on Episode #458 of The Tonic Talk Show/Podcast, HRV can offer insight into how your body responds to stress, a major factor in your overall health.
Nelson is a wellness researcher, writer and faculty member at the Nova Institute of Health in Baltimore. This article summarizes our conversation.
What Is Heart Rate Variability?
Heart rate variability (HRV) refers to the small variations in the time between consecutive heartbeats. Most people think our heart rate is regular. It isn’t. The intervals between heartbeats vary slightly depending on factors such as what we’re doing and changes in our surroundings.
Higher HRV is generally associated with a greater ability to adapt to changing demands and with better health. Lower HRV may suggest reduced adaptability and can be associated with chronic stress and poorer health.
According to Nelson, “HRV can’t tell us how exactly stressed we are, but it can definitely tell us that we’re stressed.”
How Does Heart Rate Variability Work?
Your heart rate changes depending on what you’re doing and what’s happening around you. When you’re relaxed, it tends to slow down. When you’re exercising or sense danger, it speeds up.
Your autonomic nervous system signals your heart to speed up or slow down. As Nelson explains, “Your nervous system dynamically and continually adjusts the timing for our heart.” These adjustments involve the sympathetic and parasympathetic branches of the autonomic nervous system.
- The sympathetic nervous system activates the body’s fight, flight or freeze response. It increases heart rate and blood pressure, helping deliver blood to the muscles and brain so the body can respond to a challenge.
- The parasympathetic nervous system supports rest, relaxation and recovery. It helps slow the heart rate and allows the body to return to a calmer state.
What Does Heart Rate Variability Tell Us?
Higher HRV is generally associated with a greater capacity to adapt to changing demands.
Lower HRV may indicate reduced resilience and a diminished ability to adapt to stress. People with lower HRV may also have a higher resting heart rate. With more beats per minute, there is less time between beats, which can limit the opportunity for variation. A higher resting heart rate can be associated with conditions such as high blood pressure, diabetes, anxiety and depression.
Lower HRV may also indicate that your body is less prepared to handle additional stress. Nelson offers the example of professional athletes who monitor their HRV. When their readings are low relative to their usual baseline, they may recognize that they need more rest and recovery. When their readings are higher, they may be better prepared for a more demanding workout.
What Factors Affect Heart Rate Variability?
Nelson identifies several factors that can negatively affect HRV:
- Sleep
- Psychological stress
- Illness
- Alcohol and medications
- Exercise
- Nutrition
- Age
The better you take care of yourself, the more likely you are to support healthy HRV.
Is There an Objective Standard for Heart Rate Variability?
HRV is not a one-time measurement, nor is there a single ideal value for everyone. Although higher HRV is generally considered favourable, interpretation depends on individual circumstances.
As Nelson explains, HRV naturally tends to decline with age, and everyone has their own baseline and experiences life differently. Consistent measurements over time can offer insight into how your body is responding to stress and changes in your lifestyle.
Rather than focusing on a single reading, it’s more useful to track your HRV over time and compare it with your usual levels.
How Can We Improve Heart Rate Variability?
Your lifestyle choices can influence your HRV. Nelson recommends prioritizing good-quality sleep and maintaining a consistent sleep schedule. He also recommends reducing alcohol consumption or, preferably, avoiding it.
Daily exercise can help support healthy HRV. Even something as simple as a brisk 20-minute walk may be beneficial. Nelson also recommends avoiding highly processed foods and choosing whole foods, including fruits, vegetables and whole grains.
Finally, Nelson advocates for mindfulness practices, which may include meditation or paced breathing. He also emphasizes the importance of maintaining a positive outlook.
As he puts it, “a little bit of buoyancy in your heart; feeling that the day can be better; that you’re not losing all the time, but winning.”
