Being On Your Toes

I read a tip from a top teacher that counsels you to stay on the balls of your feet while playing.

I would find it a bit tiring. You can relax at times, resting on your whole foot, but ready to move when needed.

Furthermore, being on your toes or the balls of your feet in between moves does not mean your heels are off the ground, but rather that you are ready to put pressure on the front of the foot for your next move.