This is a very important question about the role of Mantras in Asana and Pranayama. First of all we have to understand that Yoga is not the movement of body. Yoga is the movement of Prana, an energy. That is why the Yogis were very clear that they wanted to work with Prana. In the Vedic tradition, that tool actually manifest Prana and works with Prana is mantra.
Whether it is a Pranayama technique or an Asana technique they were using Mantra as a part of the practice so that the Prana would get activated and it will move in the body the way it is meant to be.
If you think about Asana for example, in the traditional times the Yogis were doing Asana-s statically. They were not jumping from one Asana to another like monkeys will jump from one tree to the other. They were actually staying in the Asana practice for some time. What were they doing in the Asana when they were staying? The were regulating the breath.
Asana is actually a Pranayama practice. In every Asana they would stay with some focus on the breathing,because the breathing would direct the energy to certain parts of the body which the Asana would facilitate. When you twist one side the energy is focused on one side. When you twist to the other side the energy is focused on the other side. That is what they were doing in the Asana practice where they would stay and breathe. We all know that in Pranayama we have to measure the breathing capacity. Inhale equal seconds and exhale twice the duration of the inhale etc. In modern time we are using a watch to measure what is 5 seconds, what is 10 seconds etc. But think about the Yogis long time ago when they didn’t have a watch. What did they use? This is where the role of Mantra comes in. When they would stay in a position where they had to breathe inhale and exhale with equal duration they would use the same mantra during inhale and same mantra during exhale by reciting mentally. So the Mantra would become the measure of breathing.
That is not the only reason why they are using Mantras. Certain Mantras triggers certain effects on the body like Mantras on the fire or Sun or Mantras that are heating and therefore they are targeting the Pita system in the body. Whereas Mantras like water or earth are much more grounding or much more cooling, they would focus on lower Cakras in the body which is connected with Kapa.
Different Mantras have different effects as well. That is why they would choose different Mantras in Asanas and Pranayama so that these kind of effects would also manifest.
We all must remember that the Yogis did not practice Yoga sadhana whether it is Asana or Pranayama based on modern science. The Yoga has its own science and it’s the responsibility of all modern Yoga Teachers, Yoga Therapists to learn the Yoga science. Working on the Asanas and Pranayama through the modern understanding of human body like this Asana will work on this muscles or that Asana will work on that muscle is not actually very accurate. If we take that approach it is like following the blind person or referring to Google Maps of directions in Lisbon when you are actually searching for a Restaurant in Rome . It just doesn’t make sense.
The Yogis used the ancient knowledge of understanding the human body that come from both Yoga, Ayurveda and particularly Sankya Philosophy to make the tools of Yoga work. According to Sankya Philosophy the most fundamental structure in our human system, the material structure in the human system is what is called the “Sabta Tanmatra” the fundamental element of sound. So when we are using the Mantras we are influencing the very subtle system in our body and through that there is changes in the gross skystem in the body as well. This is yet another reason why Yogis used the Mantras in Asanas, Pranayama and other practices.
This is another reason why the Mantras were used in the Yoga practices because Mantras influence very subtle systems in our structure.
Viniyoga® Teacher @ Krishnamacharya Healing and Yoga Foundation