The effect of isometric exercise training on arterial stiffness: A randomized crossover controlled study

Abstract

Isometric exercise training (IET) is an effective intervention for the management of resting blood pressure (BP). However, the effects of IET on arterial stiffness remain largely unknown. Eighteen unmedicated physically inactive participants were recruited. Participants were randomly allocated in a cross‐over design to 4 weeks of home‐based wall squat IET and control period, separated by a 3‐week washout period. Continuous beat‐to‐beat hemodynamics, including early and late systolic (sBP 1 and sBP 2, respectively) and diastolic blood pressure (dBP) were recorded for a period of 5 min and waveforms were extracted and analyzed to acquire the augmentation index (AIx) as a measure of arterial stiffness. sBP 1 (−7.7 ± 12.8 mmHg, p = 0.024), sBP 2 (−5.9 ± 9.9 mmHg, p = 0.042) and dBP (−4.4 ± 7.2 mmHg, p = 0.037) all significantly decreased following IET compared to the control period. Importantly, there was a significant reduction in AIx following IET (−6.6 ± 14.5%, p = 0.02) compared to the control period. There were also adjacent significant reductions in total peripheral resistance (−140.7 ± 65.8 dynes·cm‐5, p = 0.042) and pulse pressure (−3.8 ± 4.2, p = 0.003) compared to the control period. This study demonstrates an improvement in arterial stiffness following a short‐term IET intervention. These findings have important clinical implications regarding cardiovascular risk. Mechanistically, these results suggest that reductions in resting BP following IET are induced via favorable vascular adaptations, although the intricate details of such adaptations are not yet clear.

Isometric Exercise Training and Arterial Hypertension: An Updated Review

“…Several studies have investigated the effects of IET on arterial stiffness, with mixed results. Okamoto et al [78] included a cohort of unmedicated physically inactive participants and reported improvements in augmentation index following 8 weeks of IET, a finding the authors have recently reproduced [196]. Differently, in a group of medicated hypertensives, Farah et al [54] found no significant pulse wave velocity or augmentation index changes after 12 weeks of IET.…”

Training the Vessels: Molecular and Clinical Effects of Exercise on Vascular Health—A Narrative Review

“…Isometric exercise training has also been suggested as an effective intervention for inducing favorable vascular adaptations. In detail, a recent cross-over study showed that 4 weeks of isometric training (wall squats) reduced arterial stiffness (as suggested by a reduction in the augmentation index, derived from pulse-wave reflection) and total peripheral resistance [90]. In contrast, another study [91] found an improvement of microvascular function (as assessed by peak blood flow during reactive hyperemia) with dynamic resistance training (eight exercises, 50% of maximal repetition, three sets until moderate fatigue, for 10 weeks, three times/week) and not isometric handgrip training (at 30% of maximum voluntary contraction, four sets of 2 min).…”