Intramuscular coordination emerges as a major factor of neural adaptation and comes elucidate the function exerted by the motor units in the process. The improvement in the activation of motor units is exactly what allows one of the first adaptive changes in the neuromuscular system (nighthawk et al., 2001). In improving the intramuscular functions, Weineck (1999) highlights the importance of the ability of a muscle to recruit a greater number of motor units, thereby, increasing the capacity to develop contractile force. The occurrence of intramuscular coordination takes place in step neural adaptation, when there is an increase of the request of the motor units. We can justify this fact seeing that untrained individuals can not put into action the recruitment of specific motor units for a move compared to trained athletes. Regarding the trained and untrained individuals, Weineck (1991) shows that the trained acquires the ability to activate more motor units of a muscle simultaneously. An improved intramuscular coordination is reported: Unlike untrained they can only reach a certain percentage of simultaneous recruitment of muscle fibers. Trained individuals have a much greater amount of contractile muscle fibers activated synchronously, meaning greater recruitment of motor units and with this also the overall strength of the muscle (BACURAU et al 2001, MAIOR; ALVES 2003). Reference image: BP Blogspot