Proceedings of The Physiological Society

Europhysiology 2018 (London, UK) (2018) Proc Physiol Soc 41, PCA150

Poster Communications

High-intensity resistance exercise with low repetitions maintains endothelial function

T. Morishima1, Y. Tsuchiya2, M. Iemitsu3, E. Ochi1

1. Hosei University, Kawasaki, Kanagawa, Japan. 2. Teikyo Heisei University, Tokyo, Japan. 3. Ritsumeikan University, Kusatsu, Japan.

Abnormal endothelial function marked by reduced dilation of blood vessels as blood flow increases (endothelium-dependent flow-mediated dilation; FMD) is an early hallmark of cardiovascular disease. According to the line, resistance exercise impairs endothelial function, and this impairment is thought to be mediated by sustained elevation in blood pressure. Herein, we tested the hypothesis that resistance exercise-induced endothelial dysfunction would be prevented by high-intensity resistance exercise with low repetitions. This type of resistance exercise is known to induce temporal elevation in blood pressure due to low repetitions and long resting period between sets. Thirteen young healthy subjects completed three randomized experimental trials: (1) moderate-intensity with moderate repetitions trial (moderate-moderate trial); (2) low-intensity with high repetitions trial (low-high trial); (3) high-intensity with low repetitions trial (high-low trial). Following baseline brachial artery FMD and blood pressure measurements, subjects performed resistance exercise according to the different types of trial. The intensity of moderate-moderate, low-high and high-low trials comprised of 10 repetitions for five sets at 70 % of 1RM, 40 repetitions for five sets at 30 % of 1RM, and 3 repetitions for five sets at 85 % of 1RM, respectively. Resting periods among all sets were 60 s, 60 s and 180 s, respectively. Thereafter, brachial artery FMD and blood pressure measurements were repeated 10, 30, and 60 min after the exercise. All experimental procedures and measurements were confirmed to Declaration of Helsinki and were approved by the Ethics Committee for Human Experiments at Sports Research Center, Hosei University, Japan [ID: 2017-003]. A two-way (time x trial) repeated measures analysis of variance (ANOVA) with Tukey posthoc testing was performed on all dependent variables between moderate-moderate trial and high-low trial or low-high trial and high-low trial. Significance was accepted at P ≤ 0.05. Data are expressed as means ± SE. Although systolic blood pressures were significantly elevated after exercise in all trials (P<0.05), the magnitudes of rise in blood pressure increase were significantly lower in the high-low trial than in the moderate-moderate and low-high trials (P<0.05). Importantly, moderate-moderate and high-low trials caused a significant impairment in brachial artery FMD (Baseline vs. 10 min after exercise: 7.9 ± 1.0 % vs. 3.8 % ± 1.1 in the moderate-moderate trial, 8.3 ± 1.0 % vs. 3.4 ± 1.2 % in the low-high trial, P<0.05). However, high-low trial did not alter brachial artery FMD (Baseline vs. 10 min after exercise: 7.5 ± 0.7 % vs. 8.2 ± 1.4 %). In conclusion, endothelial function was maintained by conducting high-intensity resistance exercise with low repetitions.

Where applicable, experiments conform with Society ethical requirements