An Exploration of Influence of Duration on Physiological Effects of Asanas

Physiological and Psychological Effects of Asanas

Asana (physical posture) is described as the body posture attuning stability along with ease (Bhavanani et al., 2018). Asanas have physiological significance in regulating homeostasis and autonomic balance through massage of internal organs that clears the blockages in the energy channels of the body and the body energy system becomes more balanced (Woodyard et al., 2011). The range of motion of human body parts reduces as it gets aged. A set of asanas brings a full range of motion of all joints thereby enhancing flexibility with time (Petric et al., 2014). Combination of yoga-asanas with relaxing postures such as savasana, balasana improves the cardiopulmonary system, diminishing O₂ consumption (Telles et al., 2000). Immediate effect of 30 minutes yoga-asanas brings the mind to a calm state with reduction of GSR (De et al., 2019).

The duration of performance of asanas has a significant effect on the physiology. Depending on the duration asanas it can be classified into two types such as short-term and long term. Short-term yoga-asana is defined as yoga-asanas carried out for hours (< 2 hours) in one or two sessions per day on a weekly or monthly basis. Whereas the long term yoga-asana is carried for more than a month up to 6 months. Most of the literature is based on the above two categories. However, the authors in this chapter include another classification called ‘Yogathon’. Yogathon is defined as performing asanas more than 12 hours, continuously at a stretch. There are no studies known regarding how it affects physiology and psychology of the subjects. This chapter analyses the physiological and psychological effects on health after performing 40 hours of yoga-asana without food and sleep. The physiological aspect is assessed from the variability of cardiac and pulmonary systems called cardio-respiratory variability (CRV). The psychological aspect is assessed from the galvanic skin response (GSR). CRV consists of heart rate variability (HRV), pulse rate variability (PRV), and breath rate variability (BRV). The variability depicts the characteristics of the autonomic nervous system (ANS). The ANS has sympathetic and parasympathetic divisions which control the internal organs. The authors consider the cardio-pulmonary system to describe changes in the sympathetic nervous system (SNS) and the parasympathetic nervous system (PSNS). The yogathon is generalized for the individuals, practicing asanas regularly for at least 2 to 3 years and yogathon should be performed under guidance.