What are the differences between asanas and physical exercises? Though it depends very much on the type of physical exercise, the differences, in a general sense, are as follows:
1. In the practice of asanas, oxygen consumption is reduced whereas in physical exercise it is increased.
2. In asanas the respiration rate falls, whereas in exercise it increases. Generally, physical exercises are done very quickly and with a lot of heavy breathing; therefore the respiratory system is forced to work much harder.
3. In Yoga the body temperature drops whereas in exercise it tends to rise.
4. In asanas the metabolic rate drops whereas with exercise it increases.
5. In asanas the muscles receive minimum nutrition/ oxygen and the organs receive more, whereas in physical exercise, it is the muscles that receive the most nutrition/ oxygen at the expense of the other organs. Large muscles are developed by most types of physical exercise: these bigger muscles require greater nutrition and supply of blood; when not utilised, these muscles tend to become flabby as the muscle tissue turns to fat.
6. In asanas, the blood pressure and heart rate decrease, whereas in exercise they increase with the result that the heart works harder.
7. In broad terms, Yoga practitioners need less food than people practising physical exercise.
8. Asanas help to harmonise the endocrinal secretions, balancing the emotions and giving a positive attitude to life.
9. Asanas stimulate the parasympathetic nervous system, whilst exercises stimulate the sympathetic nervous system.
10. Physical exercise tends to overwork the joints and can often engender rheumatism and stiffness later in life. The opposite is the case with asanas.
11. Asanas encourage flexibility and the capacity to adapt to the environment and to change; if done correctly, they also develop stamina.
12. Unlike most exercises, asanas are done slowly, with relaxation and awareness which also encourages co-ordination between the body systems and the mind.
13. Physical exercise tends to build up toxins in the body, whereas asanas eliminate them.
14. Asanas develop inner awareness; exercises not necessarily.
One traditional definition of Asana is very specific and does not relate particularly to physical exercise: According to Patanjali's Yoga Sutra: 'Sthiram, Sukham, Asanam' which means 'Asana is a body position and a state of being in which one can remain steady, calm and comfortable'.