If itâs under 100 beats per minute, and you are feeling okay, you are probably not experiencing a serious rhythm disturbance.â. Exercise, of course, will raise your heart rate above 100, and thatâs good (as long as you donât exceed your target heart rate). But a resting pulse that suddenly rises to 100 beat per minute or more can be a sign of tachycardia â a more serious disturbance in the rhythm of the heart.