This paper is an assignment for the teacher training program I'm attending at the Krishnamacharya Yoga Mandiram in Chennai, TN, India. Please do not copy or reprint without prior written permission.
Yoga practice has many health benefits, including benefits to cardiovascular health. In this paper we will examine the effects of yoga practice on heart rate and heart rate variability (HRV).
Effects of Yoga on Heart Rate During Āsana Practice
While a person is practicing yoga āsanas, there is an effect on the heart rate. In more vigorous postures or sequences, whether they be standing, kneeling, sitting, or lying, the heart rate will elevate, just like with any form of physical exercise.
Some examples of movements that cause an increase in heart rate are:
- a physically challenging posture, such as a pose that requires focus on balance
- a static posture or dynamic sequence that requires elevating the arms overhead
- a dynamic sequence that requires repeated bending forward and standing upright
- a static posture or dynamic sequence in which the person is upside down
The more vigorous the sequence, the more the heart rate will elevate. With rest, the heart rate will slow down. With a small duration of rest, the heart rate will slow a little bit. With a longer rest, the heart rate will eventually slow to resting heart rate.
Another way to encourage the heart rate to slow down during asana practice is to focus on the breathing. Slow breathing activates the parasympathetic nervous system, which causes the heart rate to slow down.
Long Term Effects of Yoga on Heart Rate
The physical nature of the āsana practice, moving the body through different postures, causes the body to become stronger and more flexible. The heart, which is a muscle, also becomes stronger. As the condition of the heart improves, it becomes more efficient.
Let us take a moment to consider the purpose of the heart. The heart pumps the blood to distribute oxygen and nutrients to all the parts of the body, and to remove wastes from the body. The blood must pump at a certain rate in order to effectively perform these functions.
Āsana practice improves the efficiency of the heart muscle and with this improved efficiency, the heart is able to pump a greater volume of blood with each heartbeat, which means that fewer heartbeats are needed per minute.
What this means is that a benefit of consistent āsana practice is improved condition of the heart, which enables more efficient pumping, which translates into lower resting heart rate. And lower resting heart rate is desirable because it equates with reduced risk of heart disease.
Importance of Heart Rate Variability
Heart Rate Variability is another measure of heart health that is improved with āsana practice. Heart Rate Variability (HRV) is the ability of the heart rate to reduce or increase from beat to beat.
In order to understand Heart Rate Variability, first we must understand the functioning of the nervous system.
The nervous system (also known as autonomic nervous system), is comprised of two parts, the parasympathetic nervous system (PNS) and the sympathetic nervous system (SNS).
The PNS is activated during times of calm and good feelings, and can be activated with deep breathing or relaxation practices. When the PNS is activated, the body experiences effects such as reduced heart rate, reduced respiration, and reduced blood pressure.
The SNS is activated by any kind of stressors including, but not limited to, physical danger or threat, life events, traffic, arguments, negative emotions, and job pressure. The SNS is associated with the “Fight or Flight” response, so it makes sense that when the SNS is activated the body experiences effects such as increased heart rate and respiration (to pump more oxygen to all parts of the body so that it can take action) and increased blood pressure.
The Internal Pacemaker
Within the heart there exists the Sinoatrial Node (SA Node), which receives signals from the PNS and SNS that tell it how fast to pump. It is known as the internal pacemaker because it controls the rhythm of the pumping of the heart.
In people whose SA Node is not functioning properly, it may be necessary to have a pacemaker placed to keep the heart pumping correctly.
Heart Rate Variability (HRV)
Heart Rate Variability is the ability of the heart rate to change from beat to beat., which is based off the activity of the nervous system. HRV is a more accurate measure of a person’s health than examining only the heart rate.
Calculating and interpreting HRV is a bit more complicated than my engineer mind can easily comprehend, but the main takeaway is that the PNS controls the heartbeat in the high frequency range and the SNS controls the heartbeat in the low frequency range.
Numerous studies have been conducted on the effects of yoga on HRV. The 2014 study Effect of Yoga Therapy on Heart Rate, Blood Pressure and Cardiac Autonomic Function in Heart Failure included 130 heart heart patients. Sixty-five were treated with standard medical therapy and 65 were treated with standard medical therapy plus 3 weekly yoga classes, for 12 weeks.
The authors of the study found that there was a significant decrease in heart rate and blood pressure in the yoga group as compared to control group. And perhaps more importantly, that low frequency (SNS / “Fight or Flight”) measurements decreased significantly and high frequency (PNS / Relaxation) measurements increased significantly in the yoga group compared to control group.
This is really great news because high parasympathetic activity equates to high HRV, which generally means good health. Low HRV indicates an increased likelihood of death after a heart attack.
Practicing yoga is good for you! Practicing āsana consistently is good for heart health, heart efficiency, and heart rate. Āsana and breathing have been proven to stimulate the parasympathetic nervous system, improve heart rate variability, and decrease the odds of death after heart attack. Practice yoga for overall good health!
Zelinda Yañez is a yoga teacher specializing in therapeutic yoga and private instruction. She is the owner of The Yoga Room in Round Rock, Texas.