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Elite athletes use Heart Rate Variability (HRV), resting heart rate and other metrics to manage their training regimens and recovery time. Intense training stresses the muscles, hormones, heart and lungs. By tracking these biometrics, athletes optimize their mix of recovery time and training. They train smarter, not just harder. Exercise is a form of physical stress. Mental and emotional stress also affect your body.

Both mental and physical stress may disrupt homeostasis. This can lead to metabolism issues, insomnia, heart problems, hormonal imbalances, and chronic illness. Stress management and stress reduction improve both quality and quantity of life. You can use HRV and other key biometrics to track the success of your stress management program and to plan for “recovery” just like an elite athlete.

Before we discuss applications, it helps if you understand what these biometrics measure and how stress may alter these readings in the short and long term.

How Stress Affects Your Heart and Your Oxygen Levels

Heart Rate and Stress

Most health-conscious people recognize that stress impacts well-known metrics like heart rate and blood pressure. Have you ever found that your pulse and blood pressure were higher than normal at the dentist’s office? If so, you experienced this phenomenon.

Resting heart rate measures how fast your heart beats while you rest. Many people take a resting heart rate in the morning as a quick barometer to their cardiovascular health.  Your heart rate varies day to day, and moment to moment. The following factors may alter day-to-day resting heart rate:

  • Caffeine consumption
  • The previous day’s workout
  • Quality of sleep
  • Hydration levels
  • Hormone cycle fluctuations
  • A large meal or alcohol the night before
  • Stress levels

If you consistently follow a well-designed training plan you may find that your average resting heart rate decreases along with improvements in your physical fitness.

However, as a measure resting heart rate is limited. Due to genetics, some people just have faster resting heart rates than other people. Some hormone imbalances like low thyroid levels may decrease your average resting heart rate. Due to these reasons, you may benefit even more from tracking more sophisticated data points.

SPO2 and Stress

SpO2 stands for peripheral capillary oxygen saturation. It estimates how saturated your blood is with oxygen. A healthy, fit person usually sees a SpO2 between 95% – 100%. Illness, altitude, heart disease, smoke inhalation all affect SpO2.

Your SpO2 measure may not vary quite as much as your resting heart rate and HRV, but a sudden drop often indicates stress to your body. Traditionally athletes who train in higher elevations track SPO2 to help ensure they are getting enough oxygen. With the right device this is an easy metric to track along with resting pulse.

HRV and Stress

HRV measures time between your heart beats. When you are at an optimal state of rest and wellness, your heart is ready to respond to life’s demands. The space between heartbeats varies a little depending on your needs. When your system is “stressed,” your resting heart rate may appear the same, but there may be less variation between the heartbeats.

Tracking HRV informs you of subtle changes. For example, people sometimes find their HRV decreases a couple days before they notice cold or flu symptoms.

Factors that influence HRV include:

  • Quantity and quality of sleep
  • The previous day’s workout
  • Caffeine or alcohol consumption
  • Emotional and mental stress
  • Nutritional habits
  • Hormonal fluctuations
  • Illness or injury

To learn more about these metrics, download our free white paper “The Definitive Guide To A Healthy Heart.” In the meantime, the following tips and techniques help you manage your stress.

Five Techniques To Use Biometrics in Your Stress Management Program

Take Baseline Readings

Take regular, ideally daily, readings since many factors affect biomarkers like HRV and resting heart rate. Try to take the measurements at a consistent time under similar conditions. For example, you may take your baseline reading shortly after you wake up, before you eat or drink anything, and while relaxing. A higher HRV reflects a more optimal state than a lower HRV reading. A lower resting heart rate or pulse also reflects a more relaxed state.

If you notice your HRV and SPO2 trending upwards, this is a sign that your wellness and stress management efforts are working. If your resting heart rate and blood pressure trend downward, this is also a sign of success.

Look at the Big Picture

Have you ever heard the phrase “fighting fit”? In general, maintaining a high fitness level prepares your body to better deal with stress. However, the combination of acute emotional stress *and* physical stress from a vigorous workout may weaken your body and mind. Factor your stress levels with your workouts. Take it easy if you are dealing with major stress like a family emergency or a big deadline.

Light-to-moderate exercise like walking, yoga, dancing, or recreational sports may give you an outlet to recover from stress. Alternately, in some cases you may actually benefit more from a power nap or practicing relaxation techniques than a workout if your stress levels are very high.

Consider Yoga, Tai Chi, or Meditation

Since deep breathing and relaxation temporarily elevate HRV (and lower pulse) these markers may also help guide your practice. Emerging research indicates mindful practices like yoga and tai chi may increase HRV, SPO2 and decrease blood pressure and resting pulse. Some tech-friendly yogis even take an HRV reading during relaxation post at the end of their practice.

Reduce or Manage Your Life Stress

Athletes don’t want to overtrain as they prepare for either a marathon or a sprinting race. The same applies to you while working on big projects, moving, or experiencing another major life change. If possible, simplify your life. Learn to say no and avoid taking on too much.

Take Care of Yourself

Generally when you take good care of yourself, your HRV, SPO2, and resting heart rate tend to improve. Even better, your body and mind are ready to face life’s challenges. The following healthy choices may improve your HRV in both the short and long term:

  • Get enough sleep
  • Eat a healthy, balanced diet
  • Drink enough fluids
  • Enjoy moderate activity most days and improve or maintain your physical fitness
  • Avoid smoking
  • Spend a few minutes relaxing each day whether you prefer to meditate, pray, do yoga, or practice breathing exercises.

Take control of your stress levels and your fitness. You can customize your lifestyle and measure results by tracking key metrics like HRV, SPO2, and resting heart rate. In the past, only elite athletes had this opportunity, but now these tools are  available to you. Thanks to fitness wearables like Biostrap you can easily take these metrics at home.

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Half the people reading this will show it to someone else.

Here’s why. It turns out (spoiler alert!) that a weekly massage is not a luxury, it’s one of the top 7 ways restore parasympathetic balance; in other words to keep your body in healthy homeostasis.

First, it’s important to know how our body is run by the ground control of our nervous system. It looks like this:

  • Central Nervous System (Our brain and spinal column)
    • Peripheral Nervous System (Everything else)
  • Somatic nervous system (How we move on purpose)
  • Autonomic nervous system (Things we do without thinking, like our heartbeat)
  • Sympathetic (‘fight or flight’)
  • Parasympathetic (rest and recovery)

How healthy we are depends on how well-balanced our autonomic nervous system is.

Autonomic Nervous System

Our autonomic nervous system (ANS) controls our involuntary and unconscious body functions. It keeps us alive while we sleep. It helps us breathe when we’re unconscious. It tells our heart how fast to beat and makes sure our muscles have adequate blood/oxygen when we ‘tell’ them to move. It operates without our knowledge or consent, without our lifting a finger to help.

There are 2 branches: the sympathetic nervous system (SNS) and the parasympathetic nervous system (PSNS). They do different things but function as corollaries, not opposites. Our SNS is external facing. It provides the speed, energy and fuel to thwart danger. PSNS is internally-directed. It takes care of the daily business of life: Rest. Digestion. Reproduction (yes, with a boost from our SNS during sex). It’s nicknamed Rest & Digest or Breed & Feed. Two sides of the same coin, that can only be spent together.

Within the ANS, there is a constant calibration between the sympathetic and the parasympathetic systems.

Sympathetic Nervous System (Fight or Flight)

Our body constantly scans our environment, evaluating stimuli. When we sense a threat, our sympathetic nervous system leaps into action to immediately divert resources to the parts of our body needed to fight danger.

The SNS activates our adrenal gland. Our breathing quickens, to bring in more oxygen. Our heart beats faster, to increase blood flow to our muscles. Our pupils dilate (get larger) the better to see our foe.

Digestion slows. Our mouth dries. We don’t need to use the bathroom anymore. We are ready for battle.

Parasympathetic Nervous System (Rest and Recovery)

The parasympathetic nervous system is our default setting when we are not in danger. It lets us conduct the day-to-day business of life. Eating. Sleeping. Recovering. Reproducing.

It is an anabolic process, which builds up needed compounds.

When our PSNS is activated our heart slows. Our breathing calms. Because we don’t need to run, fight or hide, our body sends blood to our organs and away from skeletal muscles. We digest our food. We make hormones. We repair our muscles. We build strength. Our body is in a state of relaxation, and this relaxation breeds recovery. The more time we spend in PSNS the healthier we are.

Hormones and Neurotransmitters

Neurotransmitters help neurons communicate with each other across a synapse. Hormones are secreted by glands. Some compounds can act as either a hormone or a neurotransmitter, and can also they can have opposite effects depending where and why they are excreted.

We have two kinds of muscle tissue. Skeletal muscle (striated muscle) is used for voluntary movement. Smooth muscle is used for involuntary actions like digestion and constriction/dilation of blood vessels.

Our nervous system uses hormones and neurotransmitters to make whatever changes in these muscles it decides we need. The main ones are: adrenaline (increases circulation and breathing), noradrenaline, and acetylcholine (slows heart rate).

Balance

The sympathetic and parasympathetic nervous systems are always operational, but there is a balance between them. One or the other is always more active. The yin and yang pull of these two systems keeps our body in homeostasis, or balance. Together they ensure that we have enough resources, in the right places, at the right time. Running from a tiger, or for a train? Your SNS sends blood to your leg muscles and oxygen to your lungs to propel you along. Kicking back after Sunday dinner to watch a game? Your PSNS will relax your skeletal muscles and send blood to your organs to speed digestion.

Exercise and the parasympathetic nervous system

Tissues need oxygen to survive. Blood brings us oxygen. When we exercise, our muscles need 15 to 25 times more oxygen than when we’re at rest. The cardiorespiratory system makes sure our blood volume is adequate to do so.

When we work out, our SNS is activated, initiating key physiological changes.

  • We sweat to regulate our temperature.
  • Our heart beats faster to bring more oxygen to our muscles.

(The UC Davis Sports Medicine Department advises using a heart rate monitor to gauge effort.)

  • We breathe faster to take in more oxygen. We might even pant.
  • Our liver releases glucose for energy.
  • Our blood pressure increases (more volume).
  • Our blood moves from our organs to our skeletal muscles.

(That’s why we don’t eat before we exercise. Exercise slows digestion. Eating makes your body choose between strength and speed or digestion. A good rule of thumb is to avoid small meals or snacks for an hour before exercise, and to wait 3 to 4 hours after a large meal.)

These changes make sure we are ready for action. But what happens when the SNS is overstimulated?

Negative impact of heightened SNS

Our SNS is designed to help us survive life-threatening emergencies. As a catabolic process, it breaks down tissue and expends energy. If we spend too long in this heightened state of SNS there will be negative consequences.

Our bodies cannot easily differentiate between real and imagined stress. Just the idea of exercise, before we start, triggers an anticipatory heart rate increase. Our bodies are not meant to have a perpetually activated SNS. Chronic stress activates our SNS.

The fight or flight response originated to save our lives, not wash us with adrenalin and dread every time our boss shows up unexpectedly or we watch a scary movie.

We toggle between each system as needed.

If we spend too much time in SNS, we neglect our PSNS and our health suffers. When medical professionals say stress is bad for you, they mean an activated SNS, without a return to SNS, is bad for you. All the negative consequences of stress are really negative consequences of SNS. Think of it as adrenalin poisoning. A little bit can save your life. Too much and you’ll be exhausted, unsettled, with cognitive decline, poor sleep, a compromised immune system, and a body that cannot repair itself.

Exercise without recovery will end in depletion, not strength.

PSNS bolsters recovery

Activating the PSNS promotes recovery and can be measured via heart rate variability. The more time we spend in PSNS the faster we bounces back, repair damage, and gain strength.

Restorative sleep helps. Our autonomic balance during REM is similar to wakefulness. During non-rapid eye movement sleep the balance shifts from SNS to PSNS dominance, bolstering recovery.

How to restore balance

So back to the massage we promised you.

Once we understand the difference between SNS and PSNS we can actively try to stimulate our PSNS. Coach Chrissy Zmijewski recommends activating our PSNS to decrease recovery time after exercise. Here are 7 fixes to restore the balance between your SNS and PSNS.

Reduce Stress

Stress is ubiquitous. Good health depends on removing or reducing whatever stressors we can control, and reduce our reactions to those we can’t.

Meditation

We can’t remove all external stress. Meditation is the best way to decrease our reactivity to stress we can’t control. It teaches us to ignore triggers. It reduces our breathing, slows our heart, and decreases our blood pressure: all signs of PSNS activation. Meditations reduce lactic acid in our muscles, promoting recovery.

Massage

Regular massage has been shown to restore balance between SNS and PSNS. Massage makes us stronger, calmer, and more able to fight infection. By activating the PSNS, massage promotes recovery. It retrains the body to move more readily into PSNS even when we’re stressed.

Breathing

Breathing straddles the peripheral nervous system and the autonomic system. It happens automatically but we can also control it. We can hold our breath for example, but we cannot stop our heart. Slowed breathing is a hallmark of PSNS. But it’s not just a symptom, it’s a signal. Slowing your breathing intentionally tells your SNS that things are okay. This activates the PSNS.

Daily breathing exercises will strengthen your lungs, improve your immune system, and decrease your resting heart rate. Here’s a simple way to activate your PSNS. Inhale for a count of 2. Hold that breathe for a count of 5. Exhale for a count of 7. Repeat.

Yoga

Like meditation, yoga will bring you into PSNS, It also bolsters your ability to decrease SNS activation when you are stressed.

Daily or weekly yoga classes, or even a quick yoga video at home, will improve your strength, flexibility and breathing.

Nutrition

Can what you eat affect your SNS/PSNS balance? Yes. Avoiding stimulants such as caffeine and sugar will facilitate PSNS. An anti-stress diet brings the right mix of protein, minerals and other nutrients to support PSNS.

Exercise

Yes, intense exercise, even the idea of it, stimulates our SNS. But regular aerobic exercise such as light jogging can actually decrease SNS activity and activate our PSNS. The key is moderation and measurement.

Unwelcome sympathy

Our sympathetic nervous system is key to our survival. But like the sympathy of a well-meaning friend, too much can be, well, too much. The more time we spend in PSNS, the healthier and stronger we’ll be. These 7 tips are a great start.

Did we miss anything?

If you have any questions, suggestions or topic requests, please reach out.