Takayuki Inami^1,, Takuya Shimizu², Reizo Baba³, Akemi Nakagaki⁴

This study aimed to investigate the acute change of static stretching (SS) on autonomic nerve activity and to clarify the effect of SS on systemic circulation. Twenty healthy young, male volunteers performed a 1-min SS motion of the right triceps surae muscle, repeated five times. The autonomic nerve activity balance was obtained using second derivatives of the photoplethysmogram readings before (pre), during, and after (post) SS. Heart rate and blood pressure (BP) were also measured. The autonomic nerve activity significantly changed to parasympathetic dominance by SS as compared with pre. In addition, for SS, the autonomic nerve activity slowly changed to sympathetic dominance after completion of all sets of stretching, but these value did not return to pre during the 5 minutes after the completion of all sets of stretching, with parasympathetic dominance continuing by 4 minutes after SS. The BP and HR transiently increased during SS and decreased after SS. In addition, HR significantly decreased after completion of all sets of SS.The possibility that the response during SS may differ from the response during active static stretching is shown.

sympathetic nerve activity, parasympathetic nerve activity, triceps surae muscle, static stretching, blood pressure, heart rate