Acute and Chronic Effects of Combined Training on BP in Hypertensives (COMBAT-H)

Acute And Chronic Effects Of Combined Strength Training On Regulatory Variables Of Ambulatory Blood Pressure In Medicated Hypertensive Patients

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.

Study Overview

• Status: Completed
• Conditions: Control Session (CON); Dynamic Strength Exercise Session; Isometric Strength Exercise Session; Combined Exercise Session; Dynamic Strength Training; Combined Strength Training; Isometric Strength Training
• Intervention / Treatment: Other: Dynamic strength training; Other: Acute Isometric Exercise Session.; Other: Control Session and Follow-up; Other: Combined strength training

Detailed Description

"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
• Enrollment (Actual): 60
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Brazil
  • Rio Grande do Sul
    • Porto Alegre, Rio Grande do Sul, Brazil, 91420-550
      • Universidade Federal do Rio Grande do Sul

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Diagnosis of Stage 1 or 2 Hypertension (according to current guidelines). Sedentary (not engaged in structured exercise programs for at least 6 months). Aged between 18 and 60 years. Stable pharmacological treatment for at least 4 weeks. Ability to perform resistance exercises.

Exclusion Criteria:

• Presence of symptomatic cardiovascular disease, heart failure, or unstable angina. Diagnosis of uncontrolled diabetes (HbA1c > 8%) or renal failure. Musculoskeletal conditions or physical limitations that contraindicate resistance training. Recent changes in antihypertensive medication within the 4 weeks prior to or during the protocol. Current smoking or excessive alcohol consumption.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Sequential Assignment
• Masking: Single

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Dynamic strength training; 8 dynamic strength exercises, with 14 repetitions, 3 sets, 1 second concentric phase and 2 seconds eccentric phase. 30 seconds of rest between sets and 1 minute and 30 seconds of rest between exercises.	Other: Dynamic strength training; 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.
Experimental: Isometric strength training; 8 isometric strength exercises. 10 seconds of isometric strength. 3 sets, 1 second concentric and 2 eccentric. 30 seconds rest between sets and 1 minute and 30 seconds rest between exercises.	Other: Acute Isometric Exercise Session.; 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
Experimental: Control group; The control group consists of maintaining their habits for 8 weeks, without strength exercises.	Other: Control Session and Follow-up; 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.
Experimental: Combined strength training; 8 resistance exercises combining dynamic repetitions with isometric components. Protocol: 3 sets of 11 repetitions, with a concentric phase of 1 second and an eccentric phase of 2 seconds combined with 10 seconds of isometric hold at the end of each set. Includes 30 seconds of rest between sets and 90 seconds between exercises.	Other: Combined strength training; 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	Baseline and 8 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	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).	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.	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.	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.	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.	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.	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.	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.	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.	Baseline and 8 weeks

Collaborators and Investigators

• Sponsor: Federal University of Rio Grande do Sul

Study record dates

Study Major Dates

• Study Start (Actual): July 26, 2025
• Primary Completion (Actual): December 23, 2025
• Study Completion (Actual): December 23, 2025

Study Registration Dates

• First Submitted: March 9, 2026
• First Submitted That Met QC Criteria: March 9, 2026
• First Posted (Actual): March 13, 2026

Study Record Updates

• Last Update Posted (Actual): March 13, 2026
• Last Update Submitted That Met QC Criteria: March 9, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Endothelial Function; Ambulatory Blood Pressure Monitoring; Isometric exercise; Resistence training; Post-Exercise hypotension
• Additional Relevant MeSH Terms: Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Primary Dysautonomias; Autonomic Nervous System Diseases; Orthostatic Intolerance; Hypotension; Post-Exercise Hypotension
• Other Study ID Numbers: 84584824.4.0000.5347

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be shared to ensure the privacy and confidentiality of the participants, in accordance with the local institutional review board and data protection regulations.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No