Objective:To observe the effects of weekly exercise time on cardiac autonomic nervous function of regular exercise youth male adults,providing reference for weekly exercise time recommendation.Methods:142?young male adults were selected as subjects,21 subjects who do not exercise regularly as control group(C),all of the other subjects were divided into four groups(G90-180,G180-300,G300-420,G420+)by weekly exercise time surveyed by questionnaire.HRV data was collected by Omegawave System,and then evaluated b...