How To Test Your Nervous System (& Why You Should)
"The nervous system holds the key to all our achievements,
struggles, and aspirations."
—Deepak Chopra
The human nervous system, comprising the central and peripheral components, is a complex network that regulates all bodily functions and influences our emotional and psychological well-being. Despite its significance, nervous system health is often neglected.
In an era where proactive healthcare and preventative measures are gaining prominence, however, the importance of testing and assessing the nervous system cannot be emphasized enough. Just as we regularly check our blood pressure, monitor cholesterol levels, or undergo dental check-ups, understanding the state of our nervous system is crucial to maintaining optimal health.
I’ve written an article about what tracking your nervous system can tell you and another one about how to improve your nervous system. Today I will explore how to test your nervous system with four specific measures.
Whether you're an elite athlete or simply an individual striving for an improved quality of life, gaining awareness of your nervous system can offer profound insights into your present state, enabling you to optimize your well-being and live more fulfilling lives.
Benefits Of Testing Your Nervous System
Tracking your nervous system is something I think everyone do at least once in their life, even if it’s just for 2 weeks. Your nervous system can provide incredible insights into your health but often times there’s a disconnect between our awareness and the signals being sent to us.
Here are just some of the reasons you should track your nervous system.
Stress management tool: Tracking your nervous system provides valuable insights into your body's response to stress. By understanding various patterns and fluctuations, you can gain a deeper awareness of your stress levels and how your nervous system is coping with it. Armed with this knowledge, you can employ effective stress management techniques, such as relaxation exercises, breathwork, meditation, or adjusting your lifestyle, to maintain a balanced and resilient nervous system.
Enhanced recovery from exercise: If you're involved in intense physical training or exercise, nervous system tracking can be a game-changer. Intense workouts can temporarily impact your autonomic nervous system, leading to decreased HRV. By monitoring your nervous system regularly, you can assess your body's readiness for training and determine if you need additional recovery time. This empowers you to prevent overtraining, reduce the risk of injuries, know which days you can really push the intensity of a workout, and ultimately improve your overall performance.
Heightened self-awareness: Tracking your nervous system metrics fosters a greater sense of self-awareness. By observing how your body responds to various activities, environments, and stressors, you can develop a deeper understanding of how your body and nervous system react. This heightened self-awareness empowers you to make informed choices about your daily routines, sleep patterns, nutrition, and stress management strategies. By aligning your lifestyle with your nervous system's needs, you can enhance your overall well-being and achieve a state of balance.
Early identification of health Issues: Consistent nervous system tracking can serve as an early warning system for potential health issues or imbalances in your autonomic nervous system. Deviations from normal patterns, such as consistently low or high HRV, can indicate underlying health conditions such as depression, anxiety, stroke, heart attacks, cardiac arrhythmias, and sleep disorders. By recognizing these patterns early on, you can seek appropriate medical advice and interventions, ensuring that any potential health concerns are addressed promptly.
Rehab management tool. Tracking your nervous system is a great tool that you and your therapist can use in your recovery from injuries such as traumatic brain injury, spinal cord injuries, neurological disorders (e.g. dementia, MS), and even musculoskeletal injuries such as sprains, strains, and fractures. In addition to being a great biofeedback tool, tracking your nervous system can help you identify when you should stress your body a little more and when you should reel it in for optimal recovery.
Tracking your nervous system, especially through HRV monitoring, offers numerous benefits. It empowers you to effectively manage stress, optimize recovery from exercise, personalize your training, enhance self-awareness, and identify potential health issues. By taking advantage of these insights, you can take proactive steps towards improving your well-being, achieving optimal performance, and maintaining a harmonious relationship between your body and mind.
4 Ways To Test Your Nervous System
1. HRV
Heart Rate Variability (HRV) is considered the most comprehensive, non-invasive biomarker. It has become the new standard in assessing the status of the CNS. HRV is the measurement of the time between each heartbeat. These tiny time differences are directly correlated to the status of your autonomic nervous system (consisting of the parasympathetic and sympathetic nervous systems)
Generally speaking, a greater high-frequency HRV score (greater variability between heartbeats) means higher parasympathetic activity. This means your body is more relaxed. A low HRV at rest means your body is more recovered and better able to perform. If your HRV is taken during activity then your sympathetic nervous system would be activated and your HRV would and should be higher.
HRV, and the theory and research surrounding it, have become a hot topic as of late. We won’t get into the weeds here but check out this site for a thorough explanation.
Tools
There are a lot of HRV monitors on the market that claim to measure HRV but many are not accurate. Here are some of the most reliable tools on the market to use to track your HRV.
Polar 10 HR strap. Pair with an HRV app such as the EliteHRV app.
This is my favorite technique and also the most accurate way to track your HRV. Put the strap on for 5 minutes in the morning while laying in bed and just relax.
CorSense monitor by EliteHRV
Important: The Apple watch alone is not an accurate HRV monitor, however, pairing the data to the breath app on the watch which has been validated to be accurate.
How To Measure Your HRV
There are 2 main algorithms to measure HRV: RMSSD and SDNN. The HRV tools above automatically tend to use one of these two algorithms (don’t worry, you won’t need to get out your TI-89). If you’re using a tool that tracks your HRV 24/7 then you can check your HRV score whenever you want. If you’re not using a 24/7 device then the most reliable way to determine your score is by using it for 3-5 minutes in a resting state at a consistent time in the morning (e.g. wake up, put a strap on, measure).
Key Points To Keep In Mind
Measure your HRV consistently. It is best to use a tool that measures 24/7. If you do not have access to this then I recommend measuring when you first wake up for a good baseline measurement for the day. Lying in bed in the morning helps to weed out other factors (e.g. caffeine, life stressors, excitement for the workout, etc.).
The same HRV score day in and day out is not the goal. Fluctuations in HRV are good just as fluctuations in training loads are good for an adapted response.
Compare your scores only to yourself. Find patterns that align with your training and your subjective recovery.
Your HRV is a measure of how your body is recovered and not necessarily how you feel.
Related:
2. The CNS Tap Test
The CNS tap test is a simple test that can be used to assess the function of the central nervous system (CNS). The CNS consists of the brain and spinal cord, which play a crucial role in transmitting and processing sensory information, coordinating motor responses, and maintaining overall body functioning. By simply tapping your finger as fast as you can, the CNS tap test reflects how well your nervous system is performing at the moment.
Tools
Download the free CNS Tap Test app (android and iOS)
How To Do It
Lay your phone on a table and put the heel of your hand in front of your phone.
Use your index finger to tap the screen as quickly as possible (the timer starts and stops automatically).
Repeat this 3 times to determine your average.
Do this test on a daily basis. If you’re using it to help determine the intensity and duration of your workout then do it immediately before a workout on training days and on rest days do it around the time you would workout.
If you’re measuring your nervous system for non-training purposes then do the CNS tap test at a consistent time first thing in the morning (before you had that cup of coffee).
Results
A higher score correlates to a higher HRV (see above) means your nervous system is more recovered. A 10% increase or decrease relative to your baseline is a strong indicator of an elevated or depressed CNS.
3. Grip Strength
Grip strength is a measure of the maximum force that can be generated by the muscles in the hand and forearm. It is a simple and non-invasive test that can be used to assess the function of the nervous system.
Since the nervous system is responsible for controlling the muscles in the body, when the nervous system is functioning properly, it sends signals to the muscles that tell them to contract, similar to the CNS tap test. A strong grip strength often points towards healthy CNS function, efficient motor neuron conduction, and intact neuromuscular junctions. Conversely, impaired grip strength raises concerns about potential neurological dysfunctions, axonal damage, or neuromuscular junction abnormalities, all indicating a less-than-optimal nervous system.
The apparent simplicity of testing how strong your grip is masks a complex interplay involving neurological control, muscular function, and the overarching capacity to generate force. Ultimately, it serves as a valuable indicator of the current state of the nervous system.
Tools
Use a dynamometer for best results.
How To Do It
Seated with feet on the floor, squeeze as hard as you can for 2 seconds.
Alternate hands and repeat 3 times per side to determine your average.
Results
The higher the score the better recovered your nervous system is.
Sidebar: In addition to helping determine the state of your nervous system, your grip strength is a great indicator of your overall health. Compare your averages to same-sex peers based on these norms.
4. CO2 Tolerance Test
The CO2 tolerance test is a simple and non-invasive test that can be used to assess the function of the autonomic nervous system (ANS). The ANS is responsible for regulating many of the body's involuntary functions, such as heart rate, breathing, and digestion.
The CO2 tolerance test involves breathing in a high concentration of carbon dioxide (CO2). This causes the body to produce more carbonic acid, which lowers the pH of the blood. The ANS responds to this change in pH by increasing heart rate and breathing rate.
People with a healthy ANS are able to tolerate higher levels of CO2 without experiencing any adverse effects, however, people with an impaired ANS may experience symptoms such as anxiety, dizziness, and lightheadedness.
In addition to strictly measuring the state of your nervous system in the moment, the CO2 tolerance test can also be used to diagnose a number of conditions, including:
Anxiety disorders: Anxiety disorders are characterized by excessive worry and fear. People with anxiety disorders often have an impaired ANS, which makes them more sensitive to CO2.
Hyperventilation syndrome: Hyperventilation syndrome is a condition in which people breathe too quickly and deeply. This can lead to a number of symptoms, including anxiety, dizziness, and lightheadedness.
Panic disorder: Panic disorder is a type of anxiety disorder that is characterized by sudden, intense panic attacks. People with panic disorder often have an impaired ANS, which makes them more likely to experience panic attacks.
Tools
A timer or stopwatch.
How To Do It
Take 3 normal breaths through the nose.
On the 4th inhale, take a full breath, hold, and start the timer.
Exhale through your nose as slowly as possible for as long as you can.
Stop the timer when air runs out or you need to inhale.
Start over if you hold your breath or swallow.
P.S. Do not loon at the table below before doing this test.
What I Do
I have used all of these recovery tests at various points in my training and in my life although I’ve primarily used HRV. The results were eye-opening because how my perception of my body’s state and my body’s actual state were, beyond incongruent at times. It was during these conflicting times that I really learned how to calibrate my lifestyle.
When it came to training, there were days of compromise (shorter distances, fewer sets, more mobility work) and days of completely ignoring the subjective or the objective (by either going all out or truly resting). I also tried to time any days that I did HIIT, sprints, and leg-focused lifting with days where my HRV is high since these workouts tend to tank my nervous system. I’ve also found that the longer I tracked my nervous system metrics during a training block the more trends I saw and the better I performed. Most importantly, I have never been injured using this testing.
When it came to life outside of training, tracking my nervous system has taught me many lessons that I have shaped my days around.
I aim to go to bed before 9:30 (which improves my deep sleep numbers)
I avoid overeating as I’ve learned that bigger meals force my HRV lower
Despite the frequent temptation, I avoid overdoing it on the coffee and I take my last sip around noon.
Read this article for some more insights.
Although I haven't been consistently tracking my nervous system for some time now, I am fully committed to reintegrating it into my routine, particularly as I age. During the periods when I did track my nervous system, I gained valuable insights about myself that have led to enduring lifestyle changes. The knowledge I acquired through this practice has been instrumental in shaping healthier habits that I intend to maintain for the long term.
Takeaway
I see a future where tracking our nervous system and other biometrics becomes mainstream. The combination of AI, big data, and research will provide universal and individualized insights to help lead us to better training and better health. Until then we need to put in some work ourselves.
Irrespective of your age, fitness level, or lifestyle, there are potential benefits to be gained from tracking your nervous system over a specific period. You can choose from four tools: HRV (Heart Rate Variability), CNS tap test, grip strength, or breath holds. Commit to performing a daily test for two weeks and observe any patterns that emerge. It's important to remember that the results are highly contextual, so make an effort to identify the relevant context. Additionally, embrace self-experimentation as part of this process. Remember, self-awareness without self-regulation is incomplete, so take this opportunity to gain a deeper understanding of your body using these strategies and enjoy the process.
