What is the difference between yogic asanas and physical exercise?
Dr. Swami Nirmalananda:The term 'physical exercise' includes a wide range of activities, from aerobics, walking, jogging, various martial arts to swimming. Some of these activities may also influence the personality at a more subtle level. Therefore, not all the observations below will apply to all types of physical exercise.
Both asana and exercise use muscles to influence various physiological systems and the mind, but actually they have little in common. The aim of physical exercise is to strengthen the muscles and the whole body and to achieve a state of good health. The second purpose of exercise is to burn extra calories and excess fat through working out thereby achieving good health.
What is the aim of yogic asana? Yoga has many branches, and asanas constitute a part of only two branches of yoga, hatha yoga and raja yoga. In bhakti yoga, karma yoga or jnana yoga there is no mention of asana.
The asanas of hatha yoga aim at balancing the two energies in the body, the mental and pranic energy, ida and pingala. The aim of asana in raja yoga, as stated in Sage Patanjali's Yoga Sutras (2:46) is sthira sukham aasanam, to maintain sustained steadiness of the body with comfort.Sthira means steady and sukham means comfortable. Therefore, the aim is totally different in these two systems of yoga. Attaining good health is not the aim of asanas in either system of yoga, it only happens as a by-product. In physical exercise, preventing disease or ill health and promoting good health is the main aim.
In physical exercise the muscles are trained to contract strongly and sustain the contraction or to dynamically contract and relax alternately. The emphasis is on strength and endurance and as a result the muscle mass expands and the girth of the muscles increases. The number of muscle fibres in each muscle, its strength and tone increase. When properly exercised, muscles become firm and hard to the touch. Exercise increases wear and tear in the tissues, and at times can even be injurious.
In yogic asana, the muscles are initially contracted and then partly relaxed. When moving into an asana, a whole group of muscles is contracted, and when holding the final position of an asana, a large proportion of the contracted muscle fibres relaxes, bringing in a state of sukham or comfort. The muscles are being trained to contract and relax at the same time. They become strong, but the muscle mass never increases during asana practice. Besides, when a muscle is contracted and the contraction is maintained, the opposite muscle is being stretched, which produces a counter-effect.
In certain asanas, as in tadasana, every muscle is being stretched. After the stretch, the muscle can contract more vigorously. When a cricketer is bowling, for example, he takes his hand all the way back. If he is just throwing the ball by taking the hand upwards, he is throwing it with a certain force, but if he takes the hand up and back, then the contraction of the front muscles is stronger. Therefore, stretching helps to improve the contractile force of a muscle and in general makes the muscles more supple. Muscle tone is normal, and the muscle of a yogi is firm yet soft to the touch.
The bones increase in strength much more with exercise than with the practice of yogic asana. Stretching the muscles improves the flexibility of the joints and as a result asanas are more effective than exercise in improving flexibility.
Exercise stimulates the sympathetic autonomic nerves leading to an increased basal metabolic rate, burning of calories, heat production and a rise in body temperature. Asanas usually have a parasympathetic stimulating effect. Only some asanas are heat-producing. Many asanas are gentle and have no influence on body temperature. The relaxation asanas may actually have a cooling effect. In other words, the basal metabolic rate increases with exercise and it may stay unaltered or decrease with asana practice.
When the basal metabolic rate increases, the heart rate will go up and blood will circulate faster to compensate for the increased demand for nutrients and oxygen. The blood vessels, especially in the muscles and skin, become dilated, allowing more blood with more nutrients to flow towards the exercised muscles. The skin also needs greater blood supply to dispose of extra heat.
During asana practice if the heart rate goes up at all, it is only momentary. Overall there is a small but significant drop in the heart rate and blood pressure. With exercise the heart rate and blood pressure are either maintained or tend to go up momentarily. With exercise and asana the blood pressure ultimately settles at a slightly lower level, 2 to 4 mmHg less than before the practice.
One important difference between asana and exercise is that in an asana the blood circulates equally throughout the body. There is no special vascular dilation in the muscles and skin. In an exercise the need or demand of the muscles is so great that most of the blood goes to the muscles and skin. As a result, there is a relative lack of blood supplied to the internal organs for a short time, until the body cools down to resting level. There is a discrepancy in blood supply throughout the body in exercise but not in asana.
The respiration is fast and deep during exercise, but in asana practice it is deep, slow, synchronized with the body movements and under the full control of the practitioner. The reason is that the demand for oxygen is small, the metabolism is at rest, and therefore the breathing does not become fast during asana practice. Both exercise and asana induce a sense of well being.
What happens to the mind during exercise? The mind is active and extroverted, but can also be concentrated if one enjoys the exercise. If the asana is done correctly, the mind is introverted, because one is constantly asked to be aware of something. Therefore, the mind is internalised, one is in the present moment and has no chance to think. While doing asana the mind is not dissipated, the awareness becomes sharper and one knows the body, the state of the emotions and one's mind. Exercise does not always have this effect.
The state of awareness is actually the main difference between an asana and an exercise. However, any activity, even physical exercise, can become yoga if the heart and awareness are fully in what one is doing.