An exercise sensing method, an exercise sensing apparatus and an exercise sensing system are provided. The exercise sensing system includes a computing device, a storage device and at least one biophysical quantity sensor disposed on at least one muscle portion of a user. In the method, a current muscle strength of the muscle portion when the user performs an exercise is monitored by the biophysical quantity sensor. An exercise history of the user is accessed to obtain a muscle strength reference value of the muscle portion when the user previously performed the exercise. The current muscle strength is compared with the muscle strength reference value so as to adjust an exercise intensity of the exercise.