A method of measuring muscular fitness of a user using a wearable device includes determining a target resistance profile for a target movement to be performed by the user wearing the wearable device to measure muscular fitness, controlling a motor driver circuit of the wearable device based on the target resistance profile to control a resistance force to be provided to the user, measuring state information of an actual movement performed by the user under the resistance force, and measuring the muscular fitness of the user based on the state information.