Resistance exercise lowers blood pressure and improves vascular endothelial function in individuals with elevated blood pressure or stage-1 hypertension

Abstract

Lifestyle modifications are the first-line treatment recommendation for elevated blood pressure (BP) or stage-1 hypertension (E/S1H) and include resistance exercise training (RET). The purpose of the current study was to examine the effect of a 9-wk RET intervention in line with the current exercise guidelines for individuals with E/S1H on resting peripheral and central BP, vascular endothelial function, central arterial stiffness, autonomic function, and inflammation in middle-aged and older adults (MA/O) with untreated E/S1H. Twenty-six MA/O adults (54 ± 6 yr; 16 females/10 males) with E/S1H engaged in either 9 wk of 3 days/wk RET (n = 13) or a nonexercise control (Con; n = 13). Pre- and postintervention measures included peripheral and central systolic (SBP and cSBP) and diastolic BP (DBP and cDBP), flow-mediated dilation (FMD), carotid-femoral pulse wave velocity (cfPWV), cardiovagal baroreflex sensitivity (BRS), cardiac output (CO), total peripheral resistance (TPR), heart rate variability (HRV), and C-reactive protein (CRP). RET caused significant reductions in SBP {mean change ± 95% CI = [-7.9 (-12.1, -3.6) mmHg; P < 0.001]}, cSBP [6.8 (-10.8, -2.7) mmHg; P < 0.001)], DBP [4.8 (-10.3, -1.2) mmHg; P < 0.001], and cDBP [-5.1 (-8.9, -1.3) mmHg; P < 0.001]; increases in FMD [+2.37 (0.61, 4.14)%; P = 0.004] and CO [+1.21 (0.26, 2.15) L/min; P = 0.006]; and a reduction in TPR [-398 (-778, -19) mmHg·s/L; P = 0.028]. RET had no effect on cfPWV, BRS, HRV, or CRP relative to Con (P ≥ 0.20). These data suggest that RET reduces BP in MA/O adults with E/S1H alongside increased peripheral vascular function and decreased TPR without affecting cardiovagal function or central arterial stiffness.NEW & NOTEWORTHY This is among the first studies to investigate the effects of chronic resistance exercise training on blood pressure (BP) and putative BP regulating mechanisms in middle-aged and older adults with untreated elevated BP or stage-1 hypertension in a randomized, nonexercise-controlled trial. Nine weeks of resistance exercise training elicits 4- to 8-mmHg improvements in systolic and diastolic BP alongside improvements in vascular endothelial function and total peripheral resistance without influencing central arterial stiffness or cardiovagal function.

Keywords: aging; blood pressure; cardiovascular health; resistance exercise; vascular function.

Figure 1.

Overview of the experimental design. In week 1, load (10RM) for the prescribed repetitions was determined based on baseline strength testing. During weeks 2 and 3, loads (12RM) were initially determined by baseline strength testing and adjusted (+5–10%) whenever participants felt they could complete 2 repetitions more than prescribed on the final set of each exercise. During weeks 4–9, participants completed as many repetitions as possible during their final set of each exercise. Whenever a participant completed 2 or more repetitions than prescribed for 2 consecutive training sessions, the load was increased by 5–10% for the next exercise training session (e.g., 2 + 2 rule). Images created with a licensed version of BioRender.com.

Figure 2.

Peripheral systolic blood pressure (SBP), peripheral diastolic blood pressure (DBP), central SBP (cSBP), central DBP (cDBP), mean arterial pressure (MAP), and pulse pressure (PP) were collected before and following either 9 wk of resistance exercise training (RET; n = 13) or a nonexercise control period (Con; n = 13). All data are displayed as estimated marginal means (±95% CI). P ≤ 0.05, *significant within-group decrease from T0 to T1, †significantly lower in RET at T1 than in Con at T0; or #significantly lower in RET at T1 than in Con at T1.

Figure 3.

Resting cardiac output (CO) and total peripheral resistance (TPR) collected before and following either 9 wk of resistance exercise training (RET; n = 13) or a nonexercise control period (Con; n = 13). All data are displayed as estimated marginal means (±95% CI). *P ≤ 0.05, significant within-group increase from T0 to T1.

Figure 4.

Percent flow-mediated dilation (FMD), FMD corrected to shear rate (cFMD_SR), reactive hyperemia (RH), and baseline blood flow (BF_base) collected before and following either 9 wk of resistance exercise training (RET; n = 13) or a nonexercise control period (Con; n = 13). All data are displayed as estimated marginal means (±95% CI). P ≤ 0.05, *significant within-group increase from T0 to T1, or #significant difference between RET and Con at T1.

Figure 5.

Relations between the changes (Δ) in SBP and flow-mediated dilation (FMD; A); SBP and FMD corrected for shear rate stimulus (cFMD_SR; B), systolic blood pressure (SBP) and resting brachial artery diameter (D_base) (C); SBP and resting blood flow (BF_base; D); total peripheral resistance (TPR) and D_base (E); TPR and cardiovagal baroreflex sensitivity down (BRS_down; F); cardiac output (CO) and fat-free mass (FFM) (G); and pulse wave velocity (PWV) and pulse pressure (PP) following a 9-wk RET program (RET; yellow-filled circles) or nonexercise control period (Con; dark gray-filled circles) (H). Note that relations between CO vs. FFM and PWV vs. PP are depicted as rank correlations because of nonnormality of residuals. Inset text boxes also display partial correlation coefficients (r_xy,z or ρ_xy,z) for the relation with the effect of sex removed. Total n = 26 for all correlation analyses presented.