To exert for the sake of training or improvement; to practice in order to develop.
to exercise troops or horses; to exercise one's brain with a puzzle
To perform physical activity for health or training.
I exercise at the gym every day.
To use (a right, an option, etc.); to put into practice.
She is going to exercise her right to vote.
(now often in passive) To occupy the attention and effort of; to task; to tax, especially in a painful or vexatious manner; harass; to vex; to worry or make anxious.
exercised with pain
To set in action; to cause to act, move, or make exertion; to give employment to.