Tuesday March 15, 2016
Heart-rate variability is the variation in the time intervals between heart beats. Research has shown that individuals with low heart-rate variability tend to be more prone to stress and anxiety disorders. Those who have a higher heart-rate variability are less likely to develop trauma or severe forms of stress. Fortunately you can take full control over your heart-rate variability by consciously training it.
However, there is one biomarker showing promise as a broad indicator of overall health and fitness: heart rate variability (HRV), or the variation in the intervals between heart beats. If your heart beats like a metronome, with intervals of identical length between each pulse, you have low heart rate variability; this is “bad.” If your heart beats follow a more fractal pattern, with beat intervals of varying length, you have high heart rate variability; this is “good.”
This probably sounds counterintuitive. Most people assume that a steady, consistent pattern of heart beats is the healthiest. I mean, doesn’t the human body need a steady, consistent flow of blood and nutrients to its cells and tissues? But recall the musician’s lament about the drum machine – that it “has no soul.” The perfect metronomic unfoldment of the drum machine is too perfect. It’s robotic. It’s unnatural. Same with our hearts. A healthy heart (with soul) pumps as needed. It responds to the demands of the organism; it doesn’t follow preordained intervals.
In general, a high HRV indicates dominance of the parasympathetic response, the side of the autonomic nervous system that promotes relaxation, digestion, sleep, and recovery. The parasympathetic system is also known as the “feed and breed” or “rest and digest” system.
Therein lies the beauty of HRV: it offers a glimpse into the activity of our autonomic nervous system, an aspect of our physiology normally shrouded in mystery.
That’s why cardiac specialists have been using HRV for decades to track the health and recovery of their patients, and it’s why HRV is a predictive indicator of overall heart health, risk of heart attack, and other cardiac events. For instance, low HRV is associated with the development of coronary heart disease and multiple metabolic syndrome (diabetes, hypertension, high cholesterol). Low HRV is prevalent in people who’ve had heart attacks, and among patients who’ve had a heart attack, those with low HRV are at a higher risk of dying in the subsequent three years. Among the elderly, a high HRV is strongly associated with “healthy longevity,” or the kind of graceful aging relatively free of morbidity we all desire.
SweetBeat HRV correlates metrics like HRV, stress, heart rate, weight, steps, calories, and so much more.
Here’s what you’ll need to get started right away:
A heart rate monitor. Either get a chest strap (more accurate, more expensive) or a finger sensor (slightly less accurate, less expensive). Try to go for a Bluetooth-enabled model, like the Polar H7, Zephyr HxM, or Wahoo Chest Strap.
Heart rate variability smartphone app. Check to make sure your monitor is compatible with the app before you buy it. iThlete and Bioforce seem to be the most popular apps; both are available for Android and iOS. SweetBeat is another popular choice.
If your heart rate monitor isn’t Bluetooth enabled, you’ll also need an ECG receiver that connects to the monitor and plugs into your phone.
Begin your n=1 odyssey by monitoring HRV with a daily test at the same time under the same conditions. Traditionally, checking HRV first thing in the morning upon waking before coffee, breakfast, or the day’s stresses commence is the most effective time to test. The test will take just a couple minutes and the values will be recorded by the app. Do this every day. In a short time, you will have established a baseline value/normal range for HRV, and the app will have plotted a graph of your HRV history that you can refer back to against your workout/health history. Remember that really awful week of 12 hour work days as the quarter ended? It’ll probably show up on your chart as a week of low HRV. Or how about that deload week you finally managed to take last month? That’s why your HRV was remarkably high