Effects of Resistance Training Intensity on Cardiovascular Parameters of Hypertensive Women

The goal of this clinical trial is to understand about the effects of resistance training (RT) intensity on cardiovascular parameters in postmenopausal women with systemic arterial hypertension (SAH). The main research questions are:

* Does the intensity of RT impact blood pressure (BP) in postmenopausal women with SAH?
* How does RT intensity affect heart rate (HR) and their variability (HRV), endothelial function (EF), and nitric oxide (NO) biomarker synthesis in this population?
* What are the effects of RT intensity on affectivity and rate of perceived exertion (RPE)?

Researchers will compare two different intensities of RT (60% of the load for 1 repetition maximum \[1RM\] and 80% of 1RM) to determine their effects on the mentioned cardiovascular and perceptual parameters.

Participants will:

In the acute experiment:

* Perform the same RT session in a crossover design, training with 60% of 1RM in one condition and 80% of 1RM in another condition
* Have BP, HR, and HRV measured before, immediately after, and for one hour post-session
* Report affectivity before each session and at the end, along with RPE

In the chronic experiment:

* Be randomized into two groups: one training with 60% of 1RM and the other with 80% of 1RM
* Undergo a 10-week intervention period with evaluations before, during, and after the intervention
* Have BP, HR, affective responses, and RPE measured at multiple time points
* Have EF, HRV, and salivary concentrations of NO biomarkers assessed before and after the intervention

Physical training has been recommended as a non-pharmacological therapeutic strategy that can promote improvements in blood pressure levels in patients with systemic arterial hypertension (SAH). Resistance training (RT) has emerged due to the various benefits it promotes, including reducing blood pressure (BP) in this population, as improvements in heart rate variability (HRV) and endothelial function (EF). Guidelines suggest an intensity between 50% and 80% of 1 repetition maximum (1RM) in RT, reflecting a range of maximum repetitions between 9 and 26. However, there is a lack of studies that have made a direct comparison of the effect of different intensities in cardiovascular parameters of these patients. Therefore, the objective of this study will be to evaluate, acutely and chronically, the effect of RT intensity on BP, heart rate (HR), HRV, endothelial function, salivary concentrations of nitric oxide (NO) biomarker synthesis, also affectivity and rate of perceived exertion (RPE) of postmenopausal women with SAH. The study will be conducted in two stages, with two experiments: one acute and one chronic. In the acute experiment, with a crossover design, participants will perform the same RT session (with the order of these sessions being random), but in one condition they will train with 60% of 1RM and in another with 80% of 1RM. BP, HR and HRV will be measured before, at the end and for one hour after the session (hypotensive effect of the exercise). Affectivity will be measured before each test and at the end together with PSE. In the chronic study, participants will be randomized to one group that will train with 60% of 1RM and another group that will train with 80% of 1RM. Before, during and after the intervention, which will last 10 weeks, participants will be evaluated for BP, HR, affective responses and RPE, with EF, HRV and salivary concentrations of NO biomarkers measured before and after the intervention.

Eligibility Criteria:
Inclusion Criteria:

* Women with 50 to 65 old years;
* Postmenopausal diagnosis (amenorrhea for 12 months or more);
* Previous diagnosis of hypertension and treat with medications;
* Physically inactive.

Exclusion Criteria:

* History of other cardiovascular problems (heart failure, heart attack, stroke, etc);
* Grade II obesity (BMI ≥ 35 kg/m²);
* Medications (beta-blockers and/or non-dihydropyridine calcium channel blockers);
* Systolic blood pressure at rest above 160 mmHg and/or dyastolic blood presure above 105 mmHg;
* Unable to perform resistance exercise due to musculoskeletal or cognitive reasons.