According to Osho, resolve is not repression or bodily mortification when it is undertaken positively—to expand awareness of resolve itself—not as a tactic to fight a habit. Using vows (silence, fasting) to suppress tendencies creates harmful repression; using them as neutral experiments in keeping a promise is supportive. His approach expresses the repressed, not pushes it down.
Make vows as a gentle experiment in keeping your word, not as a way to fight yourself or punish your body.