Tension is a manifestation of muscle tremors caused by sympathetic excitation, which is an autonomic nerve that regulates body functions together with parasympathetic nerves. Sympathetic nerves are mainly located in the viscera, cardiovascular and glandular organs. When sympathetic nerves are excited, in addition to causing muscle tremors that lead to shivering, they also cause pupil dilation, increased heart rate, increased myocardial contraction, skeletal muscle vasodilation, bronchial diastole, mucous saliva secretion, slowed gastrointestinal motility, increased blood sugar, sweating, etc., so that the body can better respond to various stimuli. The parasympathetic nerve acts as the opposite of the sympathetic nerve, and the two together regulate the autonomic balance of the body, and shivering is a physiological phenomenon. The stimulus can be lifted through the parasympathetic nerve regulation can return to normal, usually easy to nervous when you can participate in more exercise activities to better regulate the state of mind and tension, better play level.