I received a lot of questions regarding my last post (be sure to read and watch the video if you haven't) where I talked about how to use heart rate to monitor stress, and a prior post I did for my medical group on heart rate. Before I address some of the common questions and concerns, I want to clarify the abbreviations I'm using in this post:
PNS: Parasympathetic Nervous System which regulates the relaxation response. Our goal is to activate our PNS as often as possible to
SNS: Sympathetic Nervous System which regulates our stress (aka “fight-or-flight”) response system. Our goal is to activate the SNS intermittently on demand to optimize performance, but to avoid persistent SNS activation (even if it's low-grade) which is a major underlying cause for most physical and mental disease.
HRV: Heart Rate Variability is a heart rate-based measurement that indicates if your PNS is engaged. Again, read my last post and watch the video so you understand HRV and try out an HRV-tracking app or device for additional motivation if you need it.
1. If high heart rate is an indicator of stress, then wouldn't positive emotions (excitement) that raise heart rate be unhealthy?
Great question. Heart rate can go up due to stress and anger, or from excitement and exhilaration. How does the body differentiate between these two states since they both produce an elevation in heart rate? I discussed the concept of HRV on the last post, which goes beyond the heart rate and is an indicator of how active your parasympathetic system (relaxation response) is. If your heart rate is transiently elevated from a positive emotion, you will have increased HRV, which is a good thing and indicates your PNS is active and your heart rate and breathing will rebound nicely into a healthy range. Quick activation of your PNS inhibits the prolonged surge of the stress hormone cortisol. Persistently elevated cortisol levels can increase body fat storage, elevate heart disease and chronic disease risk, and accelerate aging. Our body and mind are exquisitely sensitive to whether your elevated heart rate is attached to a negative stress (fear, anger, frustration, etc.) or a positive one (excitement, exhilaration, etc.) and the metabolic and hormonal responses will adapt accordingly. In addition, the way our primitive ancestors lived were periods of intense stress , such as fighting or fleeing from a predator or enemy, followed by periods of prolonged rest. Those rest periods allowed the PNS to kick into gear and prevent persistent cortisol elevations. Unfortunately most of us lack those prolonged rest periods. Your morning may have started off with the stress of getting your kids ready for school on time, followed by your morning commute, followed by work stress, followed by the stress of preparing a meal while managing your kids, followed by the stress of catching up on your e-mails after the kids go to sleep. This type of persistent, prolonged stress essentially burns out your PNS system so the SNS remains dominant. Your elevated heart rate may stay elevated since your PNS is not able to switch on because you refuse to rest and slow down. SNS dominance also depletes your adrenal glands from producing energizing hormones and chemicals, a condition commonly referred to as “adrenal fatigue.”
2. What about the elevation of heart rate from exercise? My heart rate often is 160 beats per minute during exercise. Isn't that bad for my health?
There's some overlap here with the first question. Exercise for most of us should be pleasurable, so again we are attaching positive emotions to our elevated heart rate. By the way, if you dread your selected form of exercise and only do it since your spouse forces you, I don't consider that a healthy or sustainable form of exercise. Every human being has a physical activity they can perform that raises their heart rate and brings them joy. It doesn't have to be a “boot camp” style work out or running on hard pavement with a miserable look on your face. It can be hiking out in nature, letting the gentle incline of the hills raise your heart rate while you breathe in fresh oxygen and admire your natural surroundings. It can be gardening in the backyard while doing a fair amount of squatting, lifting and walking. It can be a group exercise class with friends, a sport you enjoy , or one of my favorites, which is playing good ol' fashion tag with my boys at the playground, or a basketball showdown between father and son. The positive emotions attached to physical activities you enjoy will prime your PNS to kick in right away and help you transition into a calm state of mind. This is why reserving at least 10-15 minutes to “cool down” after workouts is essential so you can calm your nervous system and be mindful of that wonderful sense of peace we experience after a workout we enjoy. Don't just jump back into your chaotic life after a high stress workout. Be sure there is a rest interval in between.
The other key difference in why exercise-induced heart rate elevations are more beneficial is the way we breathe. When you are stressed and anxious, you typically breathe in a shallow fashion or in severe situations like a panic attack, you hyperventilate. When your breath remains in your chest and doesn't reach your belly, you are unable to activate a special nerve that runs along side your diaphragm called the vagus nerve. This nerve switches on the PNS to initiate the relaxation response.
Think of the SNS as the accelerator pedal on your car activated by stress that keeps your mind and body racing, while the PNS are the brakes that help slow you down.
Deep breathing is a way to turn on the brakes to prevent a head-on collision. With the deeper breathing of exercise, we also increase oxygen delivery to our muscles, brain and other vital organs. Regular exercise and improved physical fitness will eventually lower your resting heart rate. This is not only a sign of physical fitness, but also an indicator of an engaged and well-conditioned PNS that can withstand the emotional stressors of daily modern life.
There are 2 other activities we can all benefit from that help engage our diaphragm, while being attached to positive emotions. The first is laughter. A nice big, belly laugh in particular massages that diaphragm and stimulates the vagus nerve. In fact, laughter yoga, which originated in India and has now spread globally, is a way to trigger all of the beneficial hormonal and chemical changes associated laughter. Below is a TEDx presentation on laughter yoga.
The other way to positively engage your diaphragm and turn on your PNS is to sing nice and loud to your favorite music. If you're shy, do it in the car which is a perfect soundproof music studio where you can sing as loud as you want to your favorite music. Be conscious of contracting your abdominal muscles while you belt out your favorite tunes. In fact, your car, which is often associated with the stress of traffic and road rage, can be a perfect medium for stress reduction. Maybe cut back on listening to stressful news programs and introduce some comedy podcasts and sing along tracks that help mitigate the stressors of a busy work day. Stuck in traffic? Great, even more time to relax your nervous system.
3. My resting heart rate is 56, but throughout the day it jumps to 70 and then 80 and sometimes 90…am I going to die?
Don't stress about the normal daily fluctuations in your heart rate. Use your pulse as a rough indicator of stress and if you want to take it further, try monitoring HRV a few times throughout the day. If your heart rate is a little higher than normal, but you are not experiencing significant stress and are breathing normal, I wouldn't worry. If it's persistently higher than usual and you are also experiencing stress, then slow down and deepen your breathing. You can try a specific breathing interval like the 4-7-8 interval, where you breathe in to a count of 4, hold for a count of 7 and then breathe out to a count of 8. Adjust the intervals to your comfort level. Your pulse should slow down and you should feel calmer. Consider learning some essential pranayama breathing techniques that help engage the diaphragm. Even if your pulse doesn't come down completely to what you consider “normal,” slowing down your breathing and re-centering will prevent the excess release of cortisol which can cause a whole host of unfavorable side effects from excess belly fat to memory loss. Don't obsess over the normal variations in your heart rate throughout the day. The last thing you need is another source of stress in your life! If your heart rate remains persistently elevated despite trying a relaxation technique and/or you have any concerning associated symptoms (chest pain, shortness of breath, light-headedness, etc.), contact your doctor right away.
Meditation: The Ultimate Way to Manage Stress and Condition your PNS
Here's a recent article on the profound brain changes that occur with meditation expressed by a Harvard neuroscientist. A primary benefit of regular meditation is that it trains and conditions your PNS to be highly active even during times of stress. Your heart rate will not go up as much and it will recover more quickly from this essential practice. We exercise to improve physical and aerobic fitness, but meditation improves the fitness of your PNS which is at least as important. A well conditioned PNS prevents the adverse stress-induced hormonal shifts and cellular damage that occurs from chronic, persistent stress. Many patients tell me that even when they do deep breathing during a stressful episode, their heart rate may only go down minimally or not at all. Back to our car analogy, this is a classic sign of worn out brake pads…in other words a burned out PNS that can't slow down a speeding car. The only way to repair your brake problem is by incorporating daily periods of meditation and rest to restore PNS function.
Hopefully these last 2 posts have given you some tools to be more mindful of stress and and to manage it effectively in today's high stress environment. Any apps, devices, tips or techniques you'd like to share that have helped you manage your stress?