Heart rate variability, or HRV, is a  “fitness” measure of the autonomic nervous system.
Highly individualized, it is considered one of the best metrics to determine your readiness to perform.

I was talking to a friend recently who was growing concerned over her lowered Heart Rate Variability score. I knew she was very fit and watched her nutrition and stress levels keenly so I was confused as to why her numbers were “tanking,” as she put it. Upon reflection, what I got to was that HRV is a measure of balance between the sympathetic and parasympathetic states. While we typically assume that the sympathetic part of the autonomic nervous system (the fight or flight side) is in overdrive when HRV lowers, that is not always the case. Either part can become more dominant and cause dips in HRV. Coming off a week-long training where there was a lot of meditation, what I came to suspect was that her parasympathetic system had become more dominant and was causing the lower than “normal” – for her – HRV.  It’s about balance. 

What is Heart Rate Variability (HRV)?

Heart rate variability is the time variance between the beats of your heart. When they heart rate is 60 beats per minute, it’s not beating once a second. In the space of a minute, there may be 0.9 seconds between two beats and 1.15 seconds between two others. While the inconsistency may seem like a detriment, it’s actually a good thing. The greater this variability (a higher HRV), the more “ready” your body is to execute at a high level even in stressful conditions, which predicts better resiliency.

Why does it matter?

When you have high heart rate variability, it means that your body is responsive to both sets of inputs (parasympathetic and sympathetic) and in a state of responsive balance. This signals that your body is capable of adapting to its environment and performing at its best – physically, metabolically and mentally.

On the other hand, if the heart rate variability is lower than your normal, it’s a sign that one branch is dominating (usually the sympathetic) and sending stronger signals to your heart than the other. There are times when this is a good thing–like if you’re running a race, traveling, fighting off an illness, etc. you want your body to focus on allocating resources to the areas that need energy, as opposed to “digesting”  (parasympathetic activity).

Remember you are unique

The key to remember in tracking HRV levels over time is that you will have a “normal” range. It’s prudent to watch your numbers and not get into comparing with other people. By noticing your own biorhythm you will be able to determine what causes up and down-turns in HRV and perhaps, increase your levels over time through a variety of means.

Personally I use a wearable called the Oura Ring to track my HRV, among other things and I am now much more aware – based on my morning HRV reading – if I need to back off my training and do more mindful moderate activities or if I can push a little harder on a given day. I also notice that foods to which I am intolerant (stressors) will tend to lower my HRV dramatically, as will short sleep and undue stressors.

Why HRV might fluctuate

HRV levels that are high or slightly higher than your normal range tend to be signs of good recovery. A higher HRV may be the result of:

  • A much-needed rest day
  • A cool bedroom at night
  • Participation in more mindful, low-to-moderate-intensity activities like hiking or yoga as opposed to high energy activities
  • Mindfulness meditation
  • REM sleep
  • Good hydration and proper nutrition

HRV levels that are lower than your normal range are signs of undue strain on the body. These may be the result of:

  • Dehydration
  • Consumption of alcohol
  • A meal or workout very close to bedtime
  • Illness
  • Acute and prolonged stress
  • A hot bedroom at night
  • Jet lag and inconsistent sleep patterns
  • Overtraining

How you can Improve your HRV

Sone methods for increasing HRV include:

  • Intelligent Training. Don’t overdo it and push hard for too many days without giving your body an opportunity to recover
  • Hydration. The better hydrated you are, the easier it is for your blood to circulate and deliver oxygen and nutrients to your body. Some feel that a target is roughly one ounce of water per pound of bodyweight  daily.
  • Avoid Alcohol. One night of drinking potentially decreases HRV for up to five days.
  • Consistently Healthy Diet. Poor nutrition has adverse effects on HRV, as does eating at erratic times.
  • Quality Sleep. The quality and consistency of your sleep matters. Getting to bed and waking up at similar times each day is beneficial for many aspects of health.
  • Natural Light Exposure. Getting outside in the sunlight after waking up in the morning and at dusk in the evening triggers biological processes involved with regulating sleep/wake times, energy levels and hormone production.
  • Intentional Breathing. Slow, controlled breathing techniques can positively impact your HRV. They also help to combat stress, which has been shown to inhibit heart rate variability. You can start with simple diaphragmatic breathing techniques for a few minutes several times throughout the day.
  • Mindfulness & Meditation. Practicing mindfulness and/or meditation may lead to improvements in HRV. Dedicating just one minute per day to mindfulness exercises can have real benefits to overall health outcomes.
  • Gratitude Journaling. Writing down or thinking about things for which you are thankful each day can elicit a corresponding uptick in heart rate variability. It is also linked to lowered blood pressure and decreased stress hormones.

My biggest takeaway from researching all of this is that HRV is uniquely determined. Genetics, diet, environment, weight, exercise, stress and so many other things can be factors in YOUR levels. The more your mind gets hung up on “high” and “low” measures and comparing to others, the worse your numbers might become!


If you want tips on how to improve your HRV mobility, reply to this email and I’ll set up a complimentary 30-minute coaching call.
What is your biggest learning from all of this?

metrorun

I am a master's runner who has been running for more than 25 years. I created this site to share my experiences.

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