A dumbbell that can respond to exercise status and play music by which a user can clearly understand the exercise status with the dumbbell when using the dumbbell, includes a sensor unit for sensing a movement of the dumbbell, and a control circuit containing a micro processor, a display unit, a trumpet, and a plurality of press buttons. The micro processor receives a signal of exercising, performs calculation or summation to time duration, number of times, and energy consumption of a continuous exercise, and outputs the outcomes through the display unit, based on settings of the press buttons. Voice and music generation circuits, installed inside the micro processor, can also receive a signal of exercising including number of times and time duration of a continuous exercise, output a related voice or music in a rhythm through the trumpet based on the settings of the press buttons.