Isometric Exercise Training: A Review of Hypothesized Mechanisms and Protocol Application in Persons with Hypertension

International Journal of Exercise Science 14(2): 1261-1276, 2021. According to the American Heart Association 116.4 million, or 46% of US adults are estimated to have hypertension. Although, traditional moderate intensity aerobic exercise training is associated with reducing blood pressure by 5-8 mmHg, barriers to this modality of exercise training exist. Thus, the purpose of this review is to evaluate the mechanisms and incorporation of isometric exercise training (IET) as an adjunctive mode of exercise in a population with HTN. Based upon the articles reviewed from the years 2000-2020 which incorporated IET and provided clear protocols lasting 4 or more weeks, meaningful reductions in blood pressure occurred following IET (SBP, -9.7 ± 3.3 mmHg; DBP, -4.8 ± 2.6 mmHg) which support the need to increase adoption of this exercise form into practice to help treat hypertension. Specifically, an IET program of 12-20 minutes per day, 3 times per week, could improve blood pressure reduction in those with hypertension. IET has the potential to produce significant and clinically meaningful blood pressure reductions and could serve as an adjunctive exercise modality alongside the established exercise prescription for those with hypertension

Acute cardiovascular responses to unilateral bicep curls with blood flow restriction

A consensus on the acute cardiovascular responses to low intensity (LI) resistance exercise (RE) combined with blood flow restriction (BFR) has not yet been reached. This study was designed to compare acute cardiovascular responses to a single bout of LIRE, high intensity (HI) RE, and LIRE with BFR in physically active young males. Participants completed 3 RE sessions in random order, where each session consists of 4 sets of unilateral dumbbell bicep curls. Cardiovascular hemodynamics were measured at baseline and right after each set of RE. Aortic augmentation index (AIx) was significantly higher after set 2,3,4 of RE in LI + BFR session compared to LI session (P  0.05). HI session had a higher central SBP, brachial RPP, central RPP, and aortic AIx compared to LI session after each set of RE (P  0.05). Taken together, this study showed that LIRE combined with BFR acutely augmented aortic stiffness, as also observed in HI session, but myocardial oxygen consumption was only higher in HI session when compared to LI session. Thus, although BFR did not exaggerate cardiovascular responses nor cause extra myocardial oxygen consumption, it should be prescribed with caution when control of acute aortic stiffening is necessary during RE

Intradialytic exercise increases cardiac power index

Introduction: Mortality rates are high in end-stage renal disease due to cardiovascular complications. Perfusion of the myocardium declines during and after hemodialysis sessions with the potential for aerobic exercise to mitigate these during hemodialysis. Objectives: The purpose of this study was to investigate acute changes in hemodynamics in subjects with end-stage renal disease (ESRD) during exercise. Patients and Methods: Subjects (n = 10) were monitored for 1.5 hours during hemodialysis treatment during a control (CON) and an exercise (EX) session. Subjects cycled using an ergometer strapped to the reclining dialysis chair at an RPE of 11-13 for 30 minutes during the EX session beginning at 30 min into dialysis and ending at 60 minutes. Data for systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were collected using an automated blood pressure cuff attached to the hemodialysis machine. Data for cardiac output (Q̇ ), cardiac power index (CPI), stroke volume (SV), systemic vascular resistance (SVR), and heart rate (HR) were collected using the NICaS bioelectrical impedance device. Results: During the EX session, CPI, Q̇ , SV, and HR were significantly greater (P<0.05) than the CON session. Additionally, Q̇ was significantly (P< 0.05) greater at 45 minutes and 60 minutes compared to 15 minutes. HR was significantly (P<0.05) greater at 45 minutes compared to 90 minutes. No significant interactions were found for MAP, CPI, Q̇ , HR, SV, SBP, DBP, or SVR. Conclusion: In conclusion, exercise during dialysis may decrease the likelihood of experiencing ischemic or hypotensive events by enhancing myocardial perfusion through increasing CPI and Q̇