Autonomic response to tactical pistol performance measured by heart rate variability.

Thompson, AG, Swain, DP, Branch, JD, Spina, RJ, and Grieco, CR. Autonomic response to tactical pistol performance measured by heart rate variability. J Strength Cond Res 29(4): 926-933, 2015-This study evaluated changes in autonomic tone during a tactical pistol competition. At rest and during a match, heart rate variability (HRV) was examined in 28 healthy subjects. Heart rate variability timedomain variables (including interbeat interval [IBI]) and frequency-domain variables (low frequency [LF], high frequency [HF], total power [TP]) measured during shooting were subtracted from those measured during rest to produce Delta s. The shooting task involved several, rapid tactical maneuvers. Raw time to completion and inaccurate shots (points down [PDs]) were recorded and combined to form a match score where lower values indicated superior shooting performance. Mean (+/- SD) raw time was 135.9 +/- 34.1 seconds, PDs were 78 +/- 34, and match score was 175.3 6 39.8. Shooting decreased IBI (i. e., increased heart rate) and LF. Delta LF, Delta HF, and Delta TP were independent of Delta IBI. Raw time was significantly (p <= 0.05) correlated to shooting IBI (r = 0.404) and Delta IBI (r = 20.426). Points down were significantly correlated to Delta TP (r = 0.416) and Delta LF (r = 0.376). Match score was significantly correlated to Delta IBI (r = -0.458), Delta HF (r = 0.467), Delta LF (r = 0.377), and Delta TP (r = 0.451). In conclusion, individuals with a greater decrease in IBI (and thus heart rate) performed better by accomplishing the match faster. Individuals with less change in stress-related HRV measures (LF, HF, and TP) performed better through improved accuracy. Thus, HRV-derived sympathetic response is significantly related to shooting performance and should be used to assess marksmanship effectiveness under duress.