GENDER DIFFERENCES IN CARDIOVASCULAR RESPONSE TO ISOMETRIC EXERCISE IN THE SEATED AND SUPINE POSITIONS 999

Abstract

The purpose of this study was to compare the cardiovascular responses of woman and men to isometric handgrip (IHG) exercise performed in the seated and supine positions. Sixteen women and 15 men (age 22.6 ± 4.2) performed two maximal IHG trials at 40% MVC one week apart. Blood pressure (BP) and heart rate (HR) measurements were collected at rest (RT), the first minute of exercise (MI), prior to failure (PF), and at 30 seconds of recovery following failure (RC). Mean arterial pressure (MAP), pulse pressure (PP), and rate pressure product (RPP) were calculated from BP and HR data. Repeated measures ANOVA were used to analyze data by time, gender, and position (p< 0.05). Analyses showed significant time by gender interactions for DBP and MAP. Males had significantly higher DBP than females at MI (76.2 ±8.6, 73.3± 9.3), PF (122.4 ± 11.2, 109.5 ± 13.7) and RC (85.8± 4.1, 73.4 ± 8.3) and higher MAP measurements than females at MI (120.3 ± 13.7, 105.4 ± 13.7), PF (136.4 ± 8.6, 124.3± 13.3), and RC (100.4 ±8.2, 87.6 ±8.2). Males also had significantly higher systolic blood pressure (SBP), diastolic blood pressure(DBP), and MAP throughout trials. DBP, MAP, and HR were significantly higher in the seated position than in the supine position for both genders. There were significant time effects for both genders for SBP, DBP, and MAP between RT and MI, RT, and PF, RT and RC. There were also significant differences between MI and PF, MI and RC, and PF and RC. There were significant differences in HR and RPP between RT and MI, RT and PF, MI and PF, MI and RC, and PF and RC. There were no significant differences for HR and RPP between RT and RC. It was concluded that females maintain significantly lower blood pressure and heart rate parameters than males throughout exercise at the same relative intensity of IHG contraction regardless of position.