Heart Rate Variability (HRV) is a metric that is fast becoming popular for gauging fitness and health. It reflects the heart’s ability to respond to different situations. It is as necessary for the heart to slow during rest as it is for it to speed up when needed. A high HRV is an indication of your heart’s readiness to adapt well to your environment and has several benefits for overall health.
Highlights
- The higher your HRV (greater variability between heartbeats), the better balanced your nervous system and the healthier your heart,
- Exposing the body to cold for brief intervals, stimulates the vagus nerve and activates the parasympathetic nervous system,
- Another effective way to hoist your HRV is deep sleep, with the first four hours being of special importance.
What is Heart Rate Variability?
HRV measures the time between heartbeats. Heartbeats quicken and slow constantly in response to the environment and are influenced by Autonomous Nervous System (ANS).
The ANS controls our internal organs and consists of two distinct subsystems:
- The ‘fight-or-flight’ response (triggered by the sympathetic system), tells the heart to speed up.
- The ‘rest-and-digest’ response (triggered by the parasympathetic system), slows down our heartbeats.
A high HRV means that your body is responding to both sets of responses. The higher your HRV (greater variability between heartbeats), the more responsive your body is to your environment, the better balanced your nervous system and the healthier your heart. On the other hand, a low HRV means that one set of responses is dominant, usually the sympathetic system. Chronic stress and insufficient rest can leave one stuck in sympathetic overdrive. Research shows that low HRV has been associated with an increased risk of heart disease, diabetes and hypertension.
How to improve Heart Rate Variability
‘High’ and ‘low’ HRV are relative to an individual and there is no specific ideal HRV. Gender, age, fitness, sleep, your environment and even the kind of day you are having are all factors that can affect HRV. That said, an upward trend for one’s own HRV is extremely desirable.
Here are a few ways that may increase your HRV:
1. Exercise: Staying active is one of the most effective ways of raising your HRV. Research shows that people who exercised benefited from a better balanced ANS. Data from the study demonstrated an increase in parasympathetic activity and reduction in sympathetic activity in people who trained, especially women, and was noted even when the subjects were at rest. However, avoid overtraining – low-intensity training below your aerobic (or first lactate) level since body stress and inflammation can lower HRV and increase autonomic stress. Add 45 mins of exercise to your day, at least 5 times a week, and see your HRV trend upwards.
2. Nutrition: Eating right is not just a smart and healthy choice, but it is also a shot in the arm for your HRV. Most factors associated with a healthy lifestyle like consuming fish, multivitamins and losing weight can help augment your HRV, but of special mention is the Mediterranean diet. A study involving 276 male twins has shown a clear association between the Mediterranean dietary pattern with higher HRV.
Add fresh fruits and vegetables to your diet, avoid refined carbs and sugars and consume alcohol and caffeine sparingly to see your HRV elevate.
3. Sleep hygiene: Another effective way to hoist your HRV is regular and deep sleep, with the first four hours being of special importance. Sleeping and waking up at consistent hours allows you to be in REM and deep sleep for longer. This sustains your endogenous circadian rhythm, which has a significant impact on your HRV through an increase in parasympathetic activity. However, studies have associated early morning hours with heightened cardiovascular vulnerability as maximal shifts are observed towards sympathetic activity, in coincidence with peak levels of salivary cortisol. Going out into the sunlight after waking up and watching the sky darken in the evening triggers biological processes that improve your sleep hygiene. Making your bedroom pitch dark and getting rid of melatonin-inhibiting blue light are some more ways to improve the quality of your sleep.
4. Breathing techniques: Slow, deep, controlled breathing has a positive impact on your HRV. Inhalation raises our heart rate, and exhalation slows it. Slowing your breath to about 6 breaths a minute, called ‘coherent breathing’ is a great way to rebalance our ANS. To slow your breath, try the alternate nostril breathing technique, yoga practices like Pranayam, or intentional breathing with a cycle time of 10 seconds. You will be surprised to know can deep breathing lower blood sugar.
5. Cold shower: Exposing the body to cold for brief intervals, especially the back of the neck, stimulates the vagus nerve. This activates the parasympathetic ANS and bolsters HRV. Switch to cold water for the last 15-30 seconds of your shower, try cold water immersion for five minutes after you train or experience an ice bath.
6. Natural sunlight: Exposure to sunlight impacts your overall well-being and enables the body to create essential vitamins and hormones, such as vitamin D, cortisol and melatonin. Being outdoors, especially in the morning, triggers parasympathetic nervous system activity which reflects in your HRV. Exercise or walk outdoors, sunbathe or step outdoors after waking up and in the evening to maximise gains in your HRV.
7. Hydration: The more water we have in our body, the more blood we have to deliver oxygen and nutrients to every cell. Research has demonstrated a strong link between benefits to HRV and hydration. Especially for athletes and those who train, studies have shown a significant impact of hydration immediately after exercise on HRV during recovery.
8. Limiting alcohol: Alcohol intake suppresses HRV, additionally, rather than activation of the sympathetic nervous system, consuming alcohol inhibits the parasympathetic function – this effect can persist over several days.
9. Mindfulness: Mindfulness practice, especially if set in nature, results in an upsurge of HRV, improved sleep and reduced stress – both of which are good for your HRV, too. In fact, the benefits of HRV continue to be felt even as you sleep. Dedicating even a few minutes a day to mindfulness exercises will lift your HRV.
10. Gratitude journaling: Hike in parasympathetic HRV, fall in stress hormones and drop in blood pressure have all been attributed to gratitude journaling. The act of writing down things you are thankful for is a choice you can make every day to give a fillip to your HRV.
11. Music: Listening to music is a simple, enjoyable and free hack to increase your HRV. Choose your music carefully, since research suggests that classical music raises HRV, especially for women, but baroque and rock music can depress it. Put on your favourite tracks, listen to some classical music or try some binaural beats to ramp up your HRV.
12. Spending time with close friends: We have always known that friends make us feel good and now we have scientific evidence for understanding why that happens. Findings of a study demonstrate that people who made more friends experienced an increase in HRV as compared to those who didn’t. Surround yourself with people who make you feel good – it will do your heart a world of good.
Conclusion
The measure of the variation in time between each heartbeat is called Heart Rate Variability – which is governed by the ANS. A high HRV is indicative of a well-balanced ANS and overall well-being. An ideal HRV is an individual trait and there are no set standards, but an increase in HRV has many health benefits. If your lifestyle is active or you are stressed often, adding periods of calm in your day will benefit your HRV. On the other hand, if your day is mostly sedentary, you will reap rich dividends by elevating your heart rate. Making exercise, deep breathing and a healthy diet a part of your daily routine will be rewarded with an increase in HRV.
Disclaimer: The contents of this article are for general information and educational purposes only. It neither provides any medical advice nor intends to substitute professional medical opinion on the treatment, diagnosis, prevention or alleviation of any disease, disorder or disability. Always consult with your doctor or qualified healthcare professional about your health condition and/or concerns before undertaking a new health care regimen including making any dietary or lifestyle changes.
References
- Low Heart Rate Variability in a 2-Minute Rhythm Strip Predicts Risk of Coronary Heart Disease and Mortality From Several Causes
- Heart rate variability in type 2 diabetes mellitus: A systematic review and meta-analysis
- Reduced heart-rate variability and increased risk of hypertension
- Heart Rate Variability at Rest and Exercise: Influence of Age, Gender, and Physical Training
- Autonomic recovery after exercise in trained athletes: intensity and duration effects
