Mechano-myogram (MMG) signal reflects mechanical vibration when muscle contracts. The MMG has an advantage to detect the vibration of the induced contraction voluntarily or electrically. In this paper, we measured prolonged MMG of the biceps brachii contraction at the dumbbell lifting and the hybrid training, in which muscles are electrically stimulated to provide resistance to the voluntary motion of a muscle undergoing training. The change of MMG amplitude shows the influence of muscle fatigue. At the dumbbell and hybrid training respective MMG were similar. Therefore, it is expected that MMG can detect the muscle fatigue in the hybrid training.