Updated: Feb 1, 2021
By Ana Soulia, PT, DPT |Inertia Physiotherapy Missoula, MT
Do you wish you had a crystal ball to help you understand how well your body is tolerating stress? Did you know that your body doesn't really know the difference between physical stress from exercise or illness and mental/emotional stress? Stress is stress and we respond to it in a predictable way. The Autonomic Nervous System (ANS) is responsible for regulating our stress response. It is comprised of two complimentary systems, the sympathetic and parasympathetic nervous systems.
The sympathetic nervous system is know as our fight, flight or freeze system. It is responsible for increasing our heart rate and respiratory rate to help us deal with a stressor. This results in blood being pushed from the core out to our extremities and large muscle groups. The other half of the ANS is the parasympathetic nervous system. This is our rest and digest system. The parasympathetic nervous system reduces our heart rate, slows our breathing rate and brings blood to the core and deeper structures to help you rest, digest and restore.
We are long from the days of the caveman and cavewoman and we aren't fighting tigers anymore but we are still programmed to respond to stress. The stress we experience maybe external: your boss yelled at you, you got in a fight with your spouse or someone cut you off in traffic. It may also be internally or self generated like you are training for a marathon or you are catching a cold. Either way, wouldn't it be nice to track a vital sign that allowed you to see just how well your body is handling stress? The good news is, there is and it's called Heart Rate Variability or HRV.
Heart Rate Variability/HRV is gaining traction with the advent of various fitness trackers, but it still a little known vital sign that is a direct measurement of how well your autonomic nervous system is functioning. HRV is a measurement of the duration of time between your heart beats. Your heart rate speeds up when your body is under stress. Your heart rate slows down when you are at rest. A healthy nervous system easily switches back and forth between the two systems to help you deal with stress and then return to a resting state. So what's a good heart rate variability number? The answer is somewhat individual but generally the higher the number the more heathy your autonomic nervous system is. A lower HRV reflects your body's difficultly down regulating stress meaning you're more often in fight our flight.
While products like Whoop and Oura Ring are specifically designed with HRV in mind, you can use an Apple Watch (version 3 or later) with a little tip on how to make the HRV reading more accurate. When using Apple Watch, you simply open the Health App and scroll down to Heart Rate Variability. The catch with Apple Watch is that their algorithm is only accurate for HRV if you use the Breathe App a few times a day. If you're not familiar with the Breathe App, it simply cues you sit quietly for at least a minute and take 7 slow/deep breaths. This is something we should probably all be doing anyway. If you want to be scientific about tracking your HRV, you might make it a goal perform your breaths at the same time each day to establish a baseline. Once you have developed a habit of how you measure HRV and you get a consistent reading, you can track how aspects of your life are influencing your ANS. For example, tracking Heart Rate Variability can be a useful tool to help you avoid over training. If your score starts to dip, you may need to rest and focus more on recovery that day. If it's on the higher end, you can probably push a workout without negatively impacting your nervous system.
Health problems from chronic stress are rampant in our society. Heart Rate Variability is an easy to track, visual representation for how our body is handling stress. I've personally seen my HRV go from 65 to 25 overnight when I have had a stressful week and I don't sleep well. It's a cue to reflect on the factors that may have caused this slump and helps me recognize it's time to make a plan for how to change it. If you're working on managing stress, pain, a training program, or just your life, tracking Heart Rate Variability is a helpful tool to on your journey to maximizing your health and wellness.
About the Author- Ana Soulia is a Dr. of Physical Therapy and founder of Inertia Physiotherapy in Missoula Montana. She specializes in treating persistent pain and nagging injuries. She is passionate about helping her clients move well and enjoy an active Montana Lifestyle. Her Integrative Approach to PT emphasizes the need to evaluate the whole person to effectively treat stubborn problems. If you are in the Missoula area and you'd like to know more about Ana and how her practice is different please visit www.InertiaPhysioMT.com and schedule a FREE Discovery Session.
1001 S 4th St W Suite 4
Missoula, MT 59801