Heart Rate Variability

Heart rate variability (HRV) is a topic that I’ve wanted to jump into for a while now but just haven’t had the time.  Six weeks ago I began using an HRV monitor from http://www.myithlete.com/The monitor plugs into an iPhone or iPod and utilizes a heart rate monitor chest strap.  All that’s required is 55 seconds of breathing and out pops a HRV reading. 

So the question becomes what is heart rate variability? 

The human heart is a bio-electrical pump that beats at an ever changing rate.  This rate is influenced by a myriad of different stimuli.  Everything from training, to sleep habits, to stress, to nutrition influences the heart beat.    Many people assume the heart rate only rises and falls with activity, but in healthy individuals it varies continuously according to internal and external stressors. 

HRV measures the variability between heart beats and more specifically it measures the intervals between the R waves or the in between time of a heart beat.  Behind the science, HRV is used to evaluate the cardiac state and overall functioning state of the autonomic nervous system which is vital to athletic development. 

When you breathe in the sympathetic nervous system kicks in and controls the heart.  When exhaling the vagal nerve and the parasympathetic nervous system are in control.  Breathing in speeds up the HR while exhaling slows the HR down.  Ever wonder why sports psychologists always say take a deep breathe when in a stressful athletic situation.  Makes sense now doesn’t it. 

Maybe a few deep breaths before entering the ring with him!

The following is from the OmegaWave website on HRV.

Relevant to the evaluation of adaptation is assessing the interaction between sympathetic and parasympathetic branches of the vegetative nervous system (vegetative homeostasis). A disturbance in the vegetative balance of the cardiovascular system is an early indication of a disturbance in adaptation processes. In athletes, decreased work capacity and performance stagnation result from a disturbance in adaptation to training volumes and intensities. 

HRV becomes important as an evaluation tool to show the body’s adaptability at the moment.  Its use can contain indicators to oncoming sickness, diseases, cardiac issues, and a whole host of health problems as well as nervous system issues such as fatigue, stress, etc.  When the body is fatigued or recovery hasn’t taken place, the adaptability is low.  Creating further stress on the body further inhibits adaptability and over time this process creates over-training, sickness, injuries, exhaustion, poor training results, etc.  When recovery hasn’t taken place the sympathetic nervous system is highly active.  When we are resting, or in the process of recovery, or both, the parasympathetic nervous system dominates. 

The process of sports training is highly dependent on the nervous system for not only regulating recovery, but speed of movement, skill execution and movement patterns.  Ensuring the nervous system is adaptable at that moment should be a primary emphasis in the training of any athlete and will become more so as technology advances.


  1. Have you ever heard of and/or used a product called FitBit? Similar to the HRV tool from myithlete.com it tracks motion/activity during the day, at night it tracks your sleep patterns, and they have an online tool to track what you eat and compare it to your activity level.

    I’m considering purchasing one of these two and would love to get your thoughts on what could be the most useful information to track. Thanks

    1. I had not heard of it. Thanks for the heads up. I’m checking into it as we speak. I still don’t quite understand how it monitors everything it does including sleep but it is interesting to say the least. I’m disappointed that they aren’t available until at least mid-November.

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