IMHO In Taiji, we should be talking about the biochemical energy in the human body rather than the dynamic energies as in mechanics.
The energy I find most important is biomechanical and not biochemical.
In the approach to Tai Chi that I have been taught, biochemical energy is something assumed and to be largely ignored.
I just came back from a fantastic two-and-a-half-day seminar with Master Yang Jun. He talked extensively about Tai Chi theory in a fairly comprehensive way. There was no discussion of chemistry that I can recall, but there was a side class by one of the Academy Instructors on biomechanics.
Master Yang talked broadly about Chinese philosophy, Tai Chi theory, body shape, practice methods, energy, and breathing. Although he did not speak from a modern scientific viewpoint, much of what he described I could understand in terms of biomechanics.
Even the discussion of breathing included a biomechanical component. He equated “Sink Qi to the Dantian” to maintaining abdominal breathing and discussed five things that can affect the breathing: mind (or mental state/emotions), body shape, body angle, weight with respect to the bubbling well, and energy (basically muscular exertion). Only this last element might contain an element of chemistry, but I think it would be unnecessary and confusing to go so far.
From a scientific standpoint, these energies( kinetic, elastic, and potential) are different from the biochemical energy(ATP). BTW What does "manage" mean in regard to those energies? How do you manage them? You may not have to answer that if you don't want to.
The principles of Tai Chi are expressed in terms of traditional Chinese philosophy. For some practitioners, this means that the philosophy is dealing with things beyond modern science. For others, it means that the philosophy is a jumble of superstition and unsupported ideas about things that would be better expressed in terms of modern science. To me, Tai Chi philosophy deals with the same physical reality as modern science, but in a framework that does not translate easily into the terms used in modern science.
Talking about kinetic, elastic, and potential energy is my best attempt at coming close to such concepts as jin, ward off energy, storing, releasing, movement, and stillness etc., used in traditional Tai Chi.
How do we manage these energies? We do so through our muscles, but as mediated by the force of gravity and the status of our tendons, ligaments, and fascia. Most external martial arts focus on manipulating the muscles, but we focus more on the status of the soft tissue, such as the tendons, ligaments, and fascia. They all form one system, but it matters at the human level what you are focused on, just as in driving a car, it matters whether you are focusing on the behavior of the car or on the position and movement of the steering wheel and pedals.
I do not understand our Tai Chi to be focused on gaining energy so much as on managing and nurturing the energy we have properly. We do not focus on having more oxygen, but rather maintaining natural abdominal breathing.
Is body movement dependent on oxygen or ATP? Of course, but I pay no particular attention to that, just as in driving I am not paying much attention to gasoline consumption or the efficiency of combustion in determining how to maneuver my car on the highway. More gas or even more powerful gas would not make me a better driver.
Take care,
Audi