Many people practice yoga for many different reasons. Yoga has been shown to help manage stress, pain, and anxiety. But what about heart health? Results from several studies suggest that yoga might also have some cardiovascular benefits. There have been anecdotal reports that yoga, through breathing exercises, stretching, postures, relaxation, and meditation, can improve general health. However, these have been poorly documented.
The heart is regulated by autonomic nervous system via two routes – the sympathetic and parasympathetic nervous systems. The sympathetic nervous system increases heart rate whereas the parasympathetic system slows it down. In order for the heart rate to be steady, these two systems should be well-coordinated to work together. However, in times when changes to the heart is necessary, e.g. due to stress, flight response, etc., the two systems should also be ready to regulate the heart rate as needed. The result is the ongoing variation in heart rate called heart rate variability or HRV. HRV is the beat-to-beat changes in the heart rate and is high in people with health hearts. In cases of cardiac abnormalities, HRV goes down.
This recent study by Indian scientists at the Indian Institute of Technology looked at the benefits of yoga by measuring HRV. They looked at the HRV “spectra” in the electrocardiograms (ECG) of 84 healthy individuals aged between 18 and 48 years, all male. Forty two of these individuals were non-yogic practitioners, and 42 were experienced yoga practitioners.
According to the researchers:
“The spectral analysis of HRV is… an important tool in exploring heart health and the mechanisms of heart rate regulation. The power represented by various spectral bands in short-term HRV is indicative of how well the heart responds to changes in the body controlled by the sympathetic and the parasympathetic nervous systems.”
The results of the spectral analysis revealed HRV seems to be higher in people practicing yoga regularly. This could be mainly due to the strengthening of the parasympathetic or vagal control through yoga. A strong vagal control would also mean better control over heart rate by the autonomic nervous system, and indicative of a healthier heart. The results will be published in the next issue of the International Journal of Medical Engineering and Informatics.