The low-intensity resistance training with blood flow restriction improves vascular endothelial function resulting in the reduction of arterial stiffness in the healthy elderly

Abstract

Background: Moderate- or high-intensity resistance training is well known to improve vascular endothelial function, resulting in the prevention of arteriosclerosis. The resistance training with blood flow reduction (BFR) performed with compressing the stem of upper or lower extremities was also reported to improve vascular endothelial function, even if it was performed at low intensity workload. However, it is unclear whether the training with BFR inhibits the progress of arteriosclerosis. The purpose of this study was to investigate whether the low-intensity resistance training with BFR improved vascular endothelial function resulting in the reduction of arterial stiffness in the healthy elderly. Methods: We recruited 38 healthy old volunteers (71±3 years, 32 males) and divided them into two training groups. The resistance training with BFR was performed by 19 subjects in BFR group, and the conventional resistance training without BFR was done by the remaining 19 in the control group. The BFR was conducted by the compression of upper and low extremities using pneumatic cuffs. The resistance training consisted of 4 movements: leg extension, leg press, rowing and chest press, while each movement was repeated 20 times per set by 20% of 1 repetition maximum (1RM). Subjects performed the training 3 sets a day and 3 times a week for 4 weeks. We assessed serum levels of high-sensitivity CRP (hs-CRP), malondialdehyde-modified LDL cholesterol (MDA-LDL) and von Willebrand factor (vWF), vascular endothelial function, arterial stiffness and muscle strength before and after the 4-week intervention. Vascular endothelial function was assessed by the reactive hyperemic index (RHI) using finger plethysmograph and vWF. We measured the brachial-ankle pulse wave velocity (ba-PWV) as an index of arterial stiffness and muscle strength in the 1RM of each resistance training. Results: The RHI increased significantly from 1.8±0.5 before the intervention to 2.1±0.6 after the intervention in the BRF group (P<0.05). The ba-PWV and vWF decreased significantly from 1220±465 cm/sec and 182.5±65.3% before the intervention to 1143±562 cm/sec (P<0.05) and 164.6±57.3% (P<0.05) after the intervention in the BRF group, respectively. The muscle strength was significantly higher after the intervention than before in the BFR group (P<0.01 or 0.05). There were no significant differences in hs-CRP and MDA-LDL before and after the intervention in the two groups. Conclusion: The low-intensity resistance training with BFR improved vascular endothelial function resulting in the reduction of arterial stiffness in the healthy elderly.