HRV and why it matters

When it comes to markers of health, Heart Rate variability (HRV) is considered one of the best objective metric markers for your physical fitness and for determining your body’s readiness to perform. But what exactly is HRV a marker of, and, perhaps more importantly, which lifestyle habits should we embrace in order to improve it?

What is heart rate variability?

As a measurement, Heart rate variability is simply the variance in time between the beats of your heart. You may be surprised to learn that within a resting heart rate, recorded as 70 beats per second, for example, the heart beats themselves are not evenly spaced out at one second apart, but are randomly spaced.

The millisecond time variance between the most widely spaced heartbeats within a one-minute period (known as RR intervals – the spiked lines visible on an EKG machine), give the HRV number. The greater this variability is, the more primed your body is to perform at a high level.

HRV as a nervous system marker

Whilst the link between HRV and performance makes this a useful marker for sport and athletic ability, perhaps even more interesting, is that the origins of this marker are from within your own autonomic nervous system, which regulates all body processes, such as blood pressure and breathing.

Your autonomic nervous system has two separate branches: parasympathetic (associated with ‘rest and digest’) and sympathetic (associated with ‘fight or flight.’) The parasympathetic nervous system is activated by slower breathing, yoga, meditation and mindfulness and results in a decrease in heart rate. The sympathetic branch reflects responses to external ‘stressors’ such as work deadlines, environmental pollution, processed foods and/or cardiovascular exercise and increases your heart rate.

Heart rate variability evolves from these two competing branches simultaneously sending signals to your heart. If your nervous system is balanced, your heart is constantly being told to beat slower by your parasympathetic system, whilst being told to beat faster by your sympathetic system. This causes a fluctuation in your heart rate: HRV.

HRV is the variance in time between the beats of your heart

Lifestyle and HRV

Having a high heart rate variability therefore is a sign that your nervous system is balanced, as your body is responsive to both sets of inputs (parasympathetic and sympathetic). A balanced body is more adaptive to internal and external changes within our ever-changing modern, urban environment.

A low HRV indicates that one branch of your nervous system (in most cases, your sympathetic branch) is more dominant. If you are actively running a race, this could be beneficial, yet more frequently it is a sign that  your body is working hard for some other reason (maybe you’re fatigued, dehydrated, stressed, or sick and in need of recovery). This leaves fewer resources available to dedicate towards exercising, competing, giving a presentation at work, sorting out a relationship difficulty etc.

Studies have shown that heart rhythm patterns provide a useful insight into our inner state and differing patterns have been recorded for a state of anger and frustration than to a sense of calm appreciation. Spending longer in a relaxed emotional state can have positive effects on our physiology, leading to improved sleep patterns, energy, mood, digestion and absorption.

How can you improve Heart Rate Variability?

As normal HRV is known to decrease with age, what can we do to maintain it? 

1. Pranyama breathing
This is a fantastic way to evoke the parasympathetic nervous system as it is particularly stimulated by breathing for long, deep breaths of around a 10 second cycle. Try inhaling for a count of 3, holding for 4 and exhaling for 5 counts. Yoga is another great way to connect movement to breath and improve your HRV.

2. Eating a healthy, balanced diet
A balanced whole food diet (such as the Mediterranean diet) has been associated with raised HRV as it is a known anti-inflammatory diet and inflammation lowers HRV. The phytonutrients, contained within a rainbow of muti-coloured vegetables and some fruits, contain antioxidants to boost the body’s ability to buffer environmental toxins. Healthy fats such as omega 3 and, found in oily fish and extra virgin olive oil, also have heart-protective qualities and help lower cholesterol and high blood-pressure. Removing potential inflammatory foods, such as caffeine and alcohol and high-sugar processed foods, also reduces the stress burden on your body. A nutritional therapist can help you to identify hidden food intolerances that may be keeping your HRV low.

3. Sleep
The first four hours of sleep are responsible for producing testosterone and human growth hormone factor. During this time the body also consolidates long-term memory, which is beneficial to emotional health and for minimising depression and anxiety. Avoid caffeine after 2pm to aid sleep and wear an eye-mask or use blackout blinds to encourage melatonin production, which triggers sleep.

4. Cold showers
Research shows that a cold shower before bed, not only improves HRV, but also maintains it through the night and into the next morning! Brrrr…

5. Heart training
Many individuals like to train their HRV by monitoring their heart rhythm patterns using a technological tool such as Heart Math ( daily, to encourage more of a parasympathetic nervous system response to stress and to ease anxiety.

More information:
Heart rate variability
HRV: influence of nutrition on health 

This self-care health hack is from Superfied expert nutritionist Karen Preece Smith

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