When the user uses taijutsu like Eight Trigrams Sixty-Four Palms for example, I understand that it uses chakra. However, what if the user is just running/punching/kicking/etc? This still counts as taijutsu, right? Does this use the user's chakra?
Punching and kicking will probably exhaust the user eventually, so is this proof that it uses chakra? In other words, when a user uses up his/her chakra, they feel exhausted. Does the reverse hold true(exhaustion means lack of chakra left)?
From http://naruto.wikia.com/wiki/Chakra:
Chakra is created when two other forms of energy, known collectively as one's "stamina", are moulded together. Physical energy is collected from each and every one of the body's cells and can be increased through training, stimulants, and exercise. Spiritual energy is derived from the mind's consciousness and can be increased through studying, meditation, and experience.
So, in case of taijutsu, the user uses kicks, punches, etc to fight. To perform these actions the user definitely requires normal energy produced by the cells in the body. Now this part of chakra (physical energy) is required to produce chakra. If the user uses this "physical energy" faster, which is the case for taijutsu, the amount of chakra produced will be less. So the user doesn't use chakra, just its production gets limited. Now in case of the 8 gates also, no chakra is used. Opening the gates removes the physical limitation on the body like more muscle movement.
No, taijutsu by itself will not use chakra but it will use up a portion of it. Let me explain.
Chakra is made by combining both the spiritual and physical energy in all of the 13 trillion or so cells in the human body (as stated by Sakura in the Naruto bridge arc).
While ninjutsu and probably genjutsu as well use up chakra (physical energy and spiritual energy), taijutsu just uses up physical energy. So no it doesn't use up chakra : just one of the ingredients.
