Low-Intensity Resistance Exercise Combined With Blood Flow Restriction is More Conducive to Regulate Blood Pressure and Autonomic Nervous System in Hypertension Patients-Compared With High-Intensity and Low-Intensity Resistance Exercise

Abstract

Background: The effect of resistance exercise on the autonomic nervous system of patients with hypertension has not been identified. Objective: To explore a suitable resistance training method for hypertension patients to regulate blood pressure (BP) and autonomic nervous system function. Method: Forty-five hypertension patients aged between 55 and 70 years were randomly equally divided into three groups: the high-intensity resistance exercise (HE) group, the low-intensity resistance exercise combined with blood flow restriction (LE-BFR) group, and the low-intensity resistance exercise (LE) group. All patients performed quadriceps femoris resistance exercise. The exercise intensity of HE, LE-BFR and LE group was 65, 30 and 30% of one repetition maximum (1RM), respectively. The LE-BFR group used pressure cuffs to provide 130% of systolic pressure to the patient's thighs during resistance exercise. The training program was 20 times/min/set with a 1-min break after each set, and was conducted five sets/day and 3 days/week, lasting for 12 weeks. The heart rate (HR), BP, root-mean-square of difference-value of adjacent RR intervals (RMSSD), low frequency (LF) and high frequency (HF) were evaluated before and after the first training and the last training. Result: Significant differences in HR were observed in both recovery states after the first and last training (p < 0.01). After 12 weeks of training, the recovery speed of HR in the LE-BFR group increased significantly (p < 0.01). The systolic blood pressures in the HE and LE-BFR group were significantly reduced (p < 0.05 and p < 0.01), and the differences among groups were significant (p < 0.01). In the last recovery state, the RMSSD of the LE group was significantly lower than that in the first recovery state (p < 0.01). The LF/HF ratios of the HE and LE groups in the resting and recovery states were increased significantly (all p < 0.01). LF/HF ratios in the LE-BFR group in the resting and recovery state were decreased significantly (both p < 0.01). Conclusion: Compared to HE and LE, LE-BFR could effectively decrease systolic pressure and regulate the autonomic nervous system function in hypertension patients.

Keywords: autonomic nervous system; blood flow restriction; blood pressure; hypertension; resistance exercise.

FIGURE 1

(A) HR in the resting state before the first and last training. (B) HR in the recovery state after the first and last training. HR1 resting state, HR in the resting state before the first training. HR2 resting state, HR in the resting state before the last training. HR1 recovery state, HR in the recovery state after the first training. HR2 recovery state, HR in the recovery state after the last training. Data are presented as the mean ± standard deviation (SD). **p < 0.01, significantly different from baseline. ##p < 0.01, significantly different among groups.

FIGURE 2

(A) SBP in the resting state before the first and the last training. (B) DBP in the resting state before the first and the last training. SBP1, SBP before the first training. SBP2, SBP before the last training. DBP1, DBP before the first training. DBP2, DBP before the last training. Data are presented as the mean ± standard deviation (SD). *p < 0.05, **p < 0.01, significantly different from baseline. ##p < 0.01, significantly different among groups.

FIGURE 3

(A) RMSSD in the resting state before the first and the last training. (B) RMSSD in the recovery state after the first and the last training. (C) RMSSD before and after the first training. (D) RMSSD before and after the last training. RMSSD1 resting state, RMSSD in the resting state before the first training. RMSSD2 resting state, RMSSD in the resting state before the last training. RMSSD1 recovery state, RMSSD in the recovery state after the first training. RMSSD2 recovery state, RMSSD in the recovery state after the last training. Data are presented as the mean ± standard deviation (SD). **p < 0.01, significantly different from baseline. #p < 0.05, significantly different among groups.

FIGURE 4

(A) LF/HF in the resting state. (B) LF/HF in the recovery state. (C) LF/HF before and after the first training. (D) LF/HF before and after the last training. LF/HF1 resting state, LF/HF in the resting state before the first training. LF/HF2 resting state, LF/HF in the resting state before the last training. LF/HF1 recovery state, LF/HF in the recovery state after the first training. LF/HF2 recovery state, LF/HF in the recovery state after the last training. Data are presented as the mean ± standard deviation (SD). **p < 0.01, significantly different from baseline. ##p < 0.01, significantly different among groups.