How to Start and Grow Your Practice (for Clinicians, not MBAs!)
Thank you to Tish Campbell, PhD, for her contributions to this article.
By the end of my book tour in 2022—one of the most amazing but intense experiences of my life—you could scrape me off the floor. (Who knew? I certainly didn’t expect it.) I was wiped out. My Oura data corroborated what I was feeling, and, particularly devastating, my HRV was stuck in the low teens. Thank goodness I’d layered an extremely needed vacation into the book experience, and we headed off to Baja California Sur. It was this vacation—and my almost immediate HRV rebound—that prompted me to trade the high-stress East Coast lifestyle for a more balanced, nurturing environment in Mexico longer term.
In my experience, having a gutted HRV really prompted me to take action—a net good thing. But in this blog, we’ve done a deep drill-down into the real utility of this ubiquitously available data point (almost all wearable devices these days include HRV) to answer the question: Tracking HRV: Is it Worth it?
What is HRV?
While your heart rate may appear steady, the time between each beat naturally fluctuates–this variation in time between consecutive heartbeats is your Heart Rate Variability (HRV). The fluctuations are driven by signals from your autonomic nervous system (ANS), which regulates essential functions like stress response, recovery, and relaxation through the interplay of the sympathetic (“fight or flight”) and parasympathetic (“rest and digest”) branches. A higher HRV is usually often a sign of a healthy and adaptable nervous system, while a lower HRV may indicate stress, fatigue, or reduced resilience. Also, research shows that a low HRV is predictive of all cause mortality and independently predictive of cardiovascular death.
Fun fact: HRV was first utilized in Russia to monitor the health of astronauts before making its way into Olympic sports and, eventually, the mainstream wellness space.
There are several factors that can influence HRV, some of which we can influence but also others we can’t:
Key Influencing Factors of Heart Rate Variability (HRV)
| Category | Examples |
| Physiological | Age, gender, genetics, hormones |
| Lifestyle | Physical activity, alcohol use, smoking, drugs, diet, stress |
| Environmental | Time of day, temperature, noise |
| Methodological | Body position, recording duration, respiration |
(Table adapted from: Source)
Research indicates that 47 to 64% of the variability in HRV between individuals can be attributed to genetic factors, meaning that nearly half to two-thirds of the differences in HRV are inherited. Thus, HRV has a strong genetic component and is less malleable than we once thought. Joel Jamieson—who was first connected with HRV by Russian scientists and is a well-known strength and conditioning coach recognized for his expertise in HRV—acknowledges that HRV is more genetically based and probably a bit less modifiable.
We can think, therefore, of our baseline HRV as primarily determined by genetics, but yes, lifestyle factors such as age, sex, fitness level, stress levels, sleep quality, hydration, diet, and even environmental conditions like altitude and temperature are also at play.
What is a “High” or “Low” HRV?
When HRV first gained popularity, lots of people were obsessed with getting their scores into the 100s and above (perhaps an ironically stressful pursuit!).
Now, we know it’s more nuanced than just gunning for a high number.
For me, using an Oura ring as my tracker, my baseline—i.e., the genetic variable—puts me somewhere in the 30s. When I was finishing the book launch, it dropped into the teens but rebounded on vacation. For someone else, these same numbers might be considered really low.
HRV Tracking Recommendations for Different Groups
It is helpful to think about the usefulness of tracking HRV based on the “group” you fall into. Understanding this can help you make better use of the data.
1. Men and post-menopausal women
If you’re male or a post-menopausal woman, HRV tracking can be a highly effective tool for monitoring overall health, athletic performance, illness, and stress. For this group, HRV trends are more stable, making it easier to detect when something is off.
Take my experience, for example. When I caught the flu this past Christmas, my Oura Ring showed my body temperature rising, HRV dropping, and heart rate spiking—even before I felt really sick. Even after I recovered, my HRV stayed low, reminding me that while I felt fine, my body was still recovering. This kind of data is a helpful nudge to slow down and avoid pushing too hard during recovery or to warn you that you might be coming down with something, so it’s best to take it easy.
2. Menstruating women
If you’re a menstruating woman, things get more complicated. HRV in women is particularly dynamic, often fluctuating at different points in the menstrual cycle due to hormonal changes. My friend and colleague, Dr. Stacy Sims is an exercise physiologist recognized for her work on how women’s unique physiology—particularly hormonal fluctuations—affects training, performance, and recovery, to include a look at HRV.
Dr. Stacy Sims’ research emphasizes the significant impact of hormonal fluctuations on HRV throughout the menstrual cycle. She highlights that HRV is typically higher during the follicular phase (low-hormone phase) due to the positive effects of estrogen, which enhances vagal tone, meaning it strengthens the activity of the vagus nerve—a key component of the parasympathetic nervous system. This increased vagal tone helps the body remain in a more relaxed and recovery-oriented state. Conversely, HRV tends to decrease during the luteal phase (high-hormone phase) when progesterone levels rise, stimulating the sympathetic nervous system and reducing HRV. These insights underscore the importance of aligning training and recovery strategies with hormonal phases, allowing women to optimize performance during periods of higher HRV and focus on restorative practices during lower HRV phases. This tailored approach not only improves athletic performance but also enhances overall well-being.
3. Aging individuals
Apart from the genetic component, aging is strongly correlated with HRV, and we see a profound reduction in HRV as we age. Jamieson emphasizes that “we can prevent the decline [of HRV] most effectively through cardiovascular fitness,” as it appears to be “the most closely tied to HRV.”
A 2024 review article highlights that the decline in HRV tends to impact women more significantly than men and multiple studies have observed notable gender differences in HRV.
Wearables – Are They Accurate Enough?
Wearables and fitness trackers have made HRV monitoring accessible to everyone, whether you’re a high-performance athlete optimizing recovery or someone managing stress and well-being, HRV offers a valuable window into how your body adapts to life’s challenges. But nuance in measurement is everywhere, and it is no different for HRV measures. HRV measures seem to vary widely based on the instrument being used, but one thing is clear, there is a precipitous decline in HRV with age.
Fitbit users show men in their 20s sport an average HRV of around 61 milliseconds (ms), which dips to about 31 ms by their 60s. Women follow a similar trend, starting at 57 ms in their 20s and also landing at 31 ms by their 60s. Users of the Oura Ring (graph below) and WHOOP also see significant drops in HRV by age.
Wearable devices offer a convenient way to track HRV, but they do not follow the standardized measurement protocols used in clinical and research settings. In formal studies, HRV is typically measured using electrocardiograms (EKGs) or chest straps under controlled conditions, often relying on short-term (5–20 minutes) or long-term (24-hour) recordings to ensure accuracy and consistency.
In contrast, wearables measure HRV continuously or at various intervals using proprietary algorithms, which can lead to variability and inconsistencies between different devices. This lack of standardization in wearable technology raises questions about accuracy and comparability with clinically validated methods. While wearables provide valuable insights and help us understand HRV through large datasets, their data should be interpreted cautiously, focusing more on trends and changes over time rather than absolute values.
The Bottom Line
HRV isn’t as modifiable as we thought, but it’s still useful: As we’ve learned more about HRV, it’s become clear that it’s less modifiable beyond your baseline than we once thought. That doesn’t mean you can’t make improvements—reducing stress and staying active can certainly help. However, if you’re already a fit, healthy person with well-managed stress, the focus should shift to maintaining your HRV and slowing its natural decline with age. And, as Joel Jamieson emphasizes, the most effective way to do this is through cardiovascular fitness.
Always think about HRV in context: HRV is most valuable when viewed as part of a bigger picture, when you are familiar with your healthy baseline and you use the same device to find and compare your baseline. The Oura Ring, for example, tracks multiple data points—heart rate, HRV, temperature—which, when considered together, provide a clearer understanding of what’s happening in your body. In this context, HRV is particularly useful for monitoring recovery during and after illness.
Don’t place too much emphasis on individual readings: Stick with the device you’re most comfortable with, but don’t put too much weight on the absolute number. Instead, focus on trends and changes over time. As clinicians, we know the importance of consistency—using the same device and measurement conditions to get the most reliable insights. And for pre-menopausal women, be mindful that your cycle can also cause HRV fluctuations.
Don’t track if it makes you more anxious! One final note: just like some clients avoid genetic testing because it can cause anxiety, tracking HRV might not be helpful if it becomes a source of stress. More data isn’t always better for everyone.
Contributing Author
Tish Campbell, PhD, CNS, is a functional nutritionist, health educator, and researcher. Based in Hawaii, Tish conducts virtual consultations through her functional nutrition clinical practice, with a focus on women’s health, longevity, and health optimization. For more information, visit her website at www.tishcampbell.com.
