Heart Rate (HR) in healthy humans is influenced by physical, emotional, and cognitive activities and physiological changes that lead to variable beat-to-beat fluctuations in HR are known as HRV. HR and HRV are perhaps the most sensitive and easily accessible indicators of autonomic regulation and vagal activity. A high resting HR and decrease in HRV is a risk factor for cardiac disease.
Studies suggest that yoga can affect cardiac autonomic regulation. Although the mechanism by which yoga influences autonomic activity is not well understood, yoga may directly stimulate the vagus nerve and enhance parasympathetic output leading to parasympathetic dominance and enhanced cardiac function, mood, and energy states, as well as enhanced neuroendocrine, metabolic, cognitive, and immune responses. The bidirectional flow of the vagus nerve allows the mediation of cognitive-behavioral and emotional responses. These responses in turn, influence organ function and the mind-body integration that occurs with many yoga practices by directly linking the input and output of the central nervous system.
Effects of Yoga on Heart Rate
While a person is practicing yoga there is an effect on the heart rate. In more vigorous postures or sequences, whether they are 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:
- Pose that requires to focus on balance
- The sequence that requires elevating the arms overhead
- The dynamic sequence that requires repeated bending forward and standing upright
- Posture 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.
Another way to encourage the heart rate to slow down during asana practice is to focus on 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 yoga i.e. 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.
Yoga 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. And a lower resting heart rate is desirable because it equates with reduced risk of heart disease.
Importance of Heart Rate Variability
Heart Rate Variability is also improved with yoga practice.
In order to understand Heart Rate Variability, first, we must understand the functioning of the nervous system.
The nervous system (also known as the 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 has 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.
HRV is a more accurate measure of a person’s health than examining only the heart rate.
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 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 study found that there was a significant decrease in heart rate and blood pressure in the yoga group as compared to the control group. And perhaps more importantly, (SNS / “Fight or Flight”) measurements decreased significantly and (PNS / Relaxation) measurements increased significantly in the yoga group compared to the 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!
Doing Yoga consistently is good for heart health, heart efficiency, and heart rate. Asanas and breathing exercises have been proven to stimulate the parasympathetic nervous system, improve heart rate variability, and decrease the odds of death after a heart attack.
Therefore practice Yoga for overall good health!
I am your cardiologist and in case of any queries please feel free to post your questions on my Facebook page or call me directly on 9560694848.
Dr. Rahul Singhal
Cardiology and Cardiac Electrophysiology
Fortis Escorts Heart Hospital Jaipur