Heart Rate Variability And Its Association With The Autonomic Response During Jump Performance In Female Soccer Players

Abstract

Heart rate variability (HRV) has been established as a valid index for examining cardiac autonomic modulation. The eccentric utilization ratio (EUR) is a novel index examining the stretch shortening cycle and is calculated by dividing the jump height of both the squat jump and counter movement jump. The reactive strength index (RSI) is another assessment examining the autonomic response of a muscle contraction when performing a drop jump test. Currently, there remains a paucity of inquiry around the association between heightened cardiac vagal modulation and improvement in jump performance when utilizing the stretch shortening cycle. PURPOSE: To examine the association between cardiac vagal modulation using rMSSD and jump performance assessments utilizing the stretch shortening cycle in healthy female collegiate soccer players. METHODS: Seventeen healthy female collegiate soccer players with an age of (mean ± SD) 18.5 ± 0.75 yr, a weight of 57.3 ± 9.2 kg, a height of 165.4 ± 7.2 cm, and a body fat % of 23.2 ± 7.4 volunteered as participants. HRV was analyzed in the supine position after a 10-min stabilization period. R-R intervals were recorded over 60-seconds using the Polar Team Pro® chest strap and were exported into Kubios HRV 3.4 (University of Kuopio, Kuopio, Finland) for HRV analyses. Each participant performed three separate squat jumps, counter movement jumps and drop jumps with their hands placed on their hips. Jump performance was assessed using a force plate (Hawkin Dynamics Force Plate, ME, USA). The highest jump was included for each analysis. Normality of each data set was examined using a Shapiro-Wilk’s test for normality (p > 0.05). Linear regression (R2) was utilized to examine the association between rMSSD and both EUR and RSI. This study was approved by and followed the recommendation of the Research Ethics Review board at Langara College. RESULTS: No significant associations were observed between rMSSD and both EUR (R2 = 0.004, p = 0.74) and RSI (R2 = 0.001, p = 0.87). CONCLUSION: HRV may not be suitable for examining the autonomic response when utilizing the stretch shortening cycle during jump performance testing. This investigation was funded by the Langara College ARC-1 grant.