OUR heartbeat is an important indicator of our vitality, one that reflects so much about our internal condition. For thousands of years, people have used heart rate and pulse quality to understand other vital systems that are linked to cardiovascular activity, such as our pulmonary system, digestion, immune function and the stress load and ability to recover.
Technology has helped us understand and interpret what it means to measure heart rate, and more recently, how important it is to determine heart rate-variability. Here’s the difference.
The average amount of times our heart beats per minute is our heart rate. Generally speaking, the lower the pulse rate, the more it reflects a body at rest. The higher the pulse rate is at rest, the more it can suggest a body that is under stress, high metabolism or ill health. Of course, heart rate “highs” and “lows” are highly individualized, but trends for resting heart rate is around 60 beats per minute, and maximum heart rate is subject to age, physical fitness, health, time of day, etc.
Heart Rate Variability (HRV)
Unlike our average pulse measurement, HRV is highly specific and even more uniquely precise. It is measured in milliseconds, and indicates the precise time between heartbeats over a specific period of time, such as 1-2 minutes. Like our heart rate, HRV can change depending on time of day, stress load, state of health, demographic, etc.
Calculating and interpreting the HRV is a relatively new science that attempts to better understand the function of our Autonomic Nervous System (ANS) rather than simply measuring our cardiovascular system’s blood flow through the body. The ANS is responsible for such functions as when we sleep and wake, when we eat, how much we exert during exercise, how much we sweat, how often we breathe, how much hormones are produced throughout the day, how to react to stress, how to rest and so much more.
As we increase our heart rate, such as through exercise or increased stress, the HRV lowers. This means that our pulse becomes more regular and beats at a more predictable interval as our cardiovascular system becomes more challenged or stressed. A lowered HRV is expected and normal during such activities and circumstances, but is generally not a good indicator of your health status if your HRV is low while at rest.
At rest, our heart rate lowers but our HRV should increase. It’s as though our heart beats in a more relaxed and comfortable state, not bound to strict timing as when it is performing a physical activity.
HRV and Subjectivity
Although there is a generally observed pattern of HRV timing for people at rest, many factors can affect it as well. Stress and lack of recovery from a prior exercise session, mental duress, the effect of food and even time of day can offset and lower HRV values. It is best to get an HRV reading at the same time of day, like in the morning after you wake up, or at rest. Take note of major stress components that are present, including whether you had a heavy exercise session the prior day. Log your observations!
HRV measurements collected over time provide the best way to understand your body’s internal function, and can be more informative and valuable to you when you can identify trends in your data. For instance, a relatively “low” HRV measured at rest on a particular morning (generally not a healthy indicator) can help you decide whether you want to take on a rigorous physical activity or workout. This is important if you are planning on competing that day, or if your body is at an optimal state to perform at its best.
If you ever considered doing HRV data collection, don’t be too concerned about specific HRV values compared to other people. After all, they may be using different devices, and they are not living your life and responding to stress and activity the same way you are. Focus instead on consistent data collection and journal your stress and activity levels. Your data is only valuable if you can link it to your individual circumstances and your past activity, which is a great predictor of future performance!
Dr. Adrian Pujayana has been providing drug-free solutions for health and wellness to adults, athletes and youth since 2000 through his private practice at Family Chiropractic Center of South Pasadena, a place for strength training and nutrition-based health care. For comments or questions, email him at firstname.lastname@example.org.