The main factor induce overtraining syndrome is the change of autonomic nerves. The physiological and psychological aspects to stress response on autonomic system modulation are extensively, the changes involve many mechanisms such as heart rate variability, stress hormones, and alteration of immune function. In order to determine if an athlete is overtrained, multiple monitoring methods may be needed to make a clearer and more effective assessment. In this article we focus on autonomic nerves as the main axis to discuss a variety of exercise monitoring methods. Among them, heart rate variability, blood leptin, and salivary amylase are not widely used in monitoring exercise training stress in Taiwan. The references of this article might be provides the methods of exercise stress monitoring in the future.