Dynamic strength training (DST) is widely recognized for promoting neuromuscular adaptations such as increased strength and hypertrophy. It is currently endorsed by treatment and prevention guidelines for systemic arterial hypertension (SAH) due to its significant effect on lowering blood pressure (BP). However, when comparing BP reduction values, isometric strength training (IST) stands out with greater magnitudes of BP reduction, although without the neuromuscular adaptations seen in DST. Given their similarities, a combination of these strategies through combined strength training (CST) is possible but has not yet been evaluated. Our hypothesis is that CST may have an additive effect compared to DST and IST alone in reducing ambulatory BP. Thus, our objective is to evaluate and compare the effects of CST, DST, and IST on regulatory variables of ambulatory BP in medicated middle-aged hypertensive patients. This thesis is structured in two parts: 1) A crossover study with medicated middle-aged hypertensive patients to identify autonomic, endothelial, and vascular responses on ambulatory BP after a single session of CST, DST, and IST. 2) A randomized clinical trial to assess the chronic effects of CST, DST, and IST on regulatory variables of ambulatory BP in medicated middle-aged hypertensive patients.
"This thesis is structured in two sequential stages: A randomized crossover trial involving medicated middle-aged hypertensive patients to identify autonomic, endothelial, and vascular responses on ambulatory blood pressure following a single session of Combined Strength Training (CST), Dynamic Strength Training (DST), and Isometric Strength Training (IST), compared to a control session. A randomized controlled trial to assess the chronic effects (8 weeks) of CST and DST on the regulatory variables of ambulatory blood pressure in medicated middle-aged hypertensive patients, compared to a non-exercising control group."
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
60
Participants in this group undergo two phases. Phase 1: A single acute exercise session consisting of 8 resistance exercises (3 sets of 11 repetitions with a 10-second isometric hold at the end of each set; 1s concentric/2s eccentric phases). Phase 2: An 8-week chronic intervention period, performing the same combined protocol 3 times a week, with intensity progressing from 50% to 65% of 1RM.
Participants in this group go through two phases. Phase 1: A single acute exercise session consisting of 8 resistance exercises (3 sets of 14 repetitions, 1 second concentric phase and 2 seconds eccentric phase, 30 seconds of rest between sets and 90 seconds between exercises) at 50% of 1RM. Phase 2: An 8-week chronic intervention period, performing the same dynamic resistance protocol 3 times a week, with intensity progressing from 50% to 65% of 1RM.
Participants in this group undergo a single acute exercise session consisting of 8 resistance exercises performed isometrically. The protocol includes 3 sets per exercise, with each set consisting of a 10-second static contraction at 50% of 1RM, with 30 seconds of rest between sets and 90 seconds between exercises
Participants in this group undergo two phases. Phase 1: A single acute control session consisting of quiet rest in a seated position for the same duration as the exercise sessions. Phase 2: An 8-week follow-up period where participants maintain their usual daily activities and pharmacological treatment without any structured exercise program.
Universidade Federal do Rio Grande do Sul
Porto Alegre, Rio Grande do Sul, Brazil
24-hour Ambulatory Blood Pressure (Systolic, Diastolic, and Mean)
Average systolic blood pressure measured over a 24-hour period using an automated ambulatory monitor (ABPM). This measure assesses the chronic effect of the 8-week training protocols compared to baseline.
Time frame: Baseline and 8 weeks
Acute 24-hour Ambulatory Blood Pressure (Systolic, Diastolic, and Mean)
Average systolic blood pressure measured over a 24-hour period following a single session of each intervention (Dynamic, Combined, Isometric, and Control) to evaluate post-exercise hypotension. This was conducted in a crossover design.
Time frame: 24 hours post-intervention
Acute Post-Exercise Blood Pressure Response
Systolic and diastolic blood pressure measured at rest (pre-intervention) and at 30 and 60 minutes following a single exercise session to evaluate the immediate post-exercise hypotension (PEH).
Time frame: Baseline, 30 minutes, and 60 minutes post-exercise.
Vascular Endothelial Function - Chronic (Flow-Mediated Dilation)
Percentage of brachial artery dilation measured via high-resolution ultrasound to evaluate the chronic adaptations of vascular endothelial function after the 8-week intervention.
Time frame: Baseline and 8 weeks
Vascular Endothelial Function - Acute Response (Flow-Mediated Dilation)
Acute changes in the percentage of brachial artery dilation following a single session of exercise. This measure evaluates the transient endothelial response at different time points.
Time frame: Baseline, 30 minutes, and 60 minutes post-exercise.
Cardiac Autonomic Modulation - Chronic (Heart Rate Variability)
Analysis of heart rate variability (HRV) parameters in both time and frequency domains (e.g., SDNN, RMSSD, LF, HF) to evaluate chronic adaptations in cardiac autonomic control after the 8-week intervention.
Time frame: Baseline and 8 weeks.
Cardiac Autonomic Modulation - Acute Response (Heart Rate Variability)
Acute changes in heart rate variability parameters following a single session of exercise. This evaluates the immediate autonomic recovery and sympathetic-vagal balance at different time points.
Time frame: Baseline, 30 minutes, and 60 minutes post-exercise.
Office Blood Pressure Adaptation (Weekly Progression)
Assessment of the progression of resting systolic and diastolic blood pressure measured before exercise sessions throughout the 8-week intervention to evaluate the time course of blood pressure adaptations.
Time frame: Baseline and weekly for 8 weeks.
Blood-based Biomarkers of Cardiovascular Health
Analysis of blood samples to evaluate biochemical markers related to cardiovascular health, such as markers of inflammation, oxidative stress, or nitric oxide bioavailability, to investigate the mechanisms underlying blood pressure changes.
Time frame: Baseline and 8 weeks
Acute Blood-based Biomarkers Response
Analysis of blood samples to evaluate the acute response of biochemical markers related to cardiovascular and endothelial health (e.g., nitric oxide metabolites, inflammatory cytokines, or oxidative stress markers) following a single session of exercise.
Time frame: Baseline, 30 minutes, and 60 minutes post-exercise.
Body Composition (Skinfold Thickness)
Assessment of body composition using skinfold thickness measurements to estimate body fat percentage and lean body mass. This measure monitors physical changes and ensures that any observed blood pressure adaptations are not solely due to changes in body fat or weight.
Time frame: Baseline and 8 weeks
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