In the manga it clearly says that the only way to enter sage mode is through NOT MOVING A SINGLE MUSCLE.
Now I would like to point out that both the diaphragm thingie which controlls your breathing, and your heart are muscles.
If you were to stop moving those muscles you would die.
This either means that
A) Sage Mode is impossible and lacks logic yada yada yada
or
B) Proof that Sage Mode can exist while moving your muscles.
Now I would like to point out that both the diaphragm thingie which controlls your breathing, and your heart are muscles.
If you were to stop moving those muscles you would die.
This either means that
A) Sage Mode is impossible and lacks logic yada yada yada
or
B) Proof that Sage Mode can exist while moving your muscles.