Acute hypotensive effect of dynamic, isometric and combined resistance exercise (dynamic + isometric) in medicated hypertensive men: hemodynamic determinants and autonomic mechanisms.

Author(s)

Laura Gomes Oliveira e Silva

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Escola de Educação Física e Esportes (EEFE/BT)
• Defense date: 2021-07-27

Examining board members

Cláudia Lúcia de Moraes Forjaz; Maria Urbana Pinto Brandão Rondon; Maria do Socorro Brasileiro Santos; Aline Mendes Gerage da Silva

• Advisor: Cláudia Lúcia de Moraes Forjaz

Abstract

Regular physical exercise is recommended for hypertension treatment. After a single session of physical exercise, blood pressure (BP) decreases. This phenomenon has been called post-exercise hypotension (PEH) and may have clinical relevancy when BP decrease has significant magnitude and lasts for several hours. Additionally, PEH can be used to predict BP adaptations to physical training. A single session of dynamic resistance exercise (DRE) or isometric handgrip (IH) appears to induce HPE, but its duration and mechanisms need to be clarified. Additionally, the combination of these resistance exercises (CRE) may potentiate the hypotensive effect, which has not been investigated yet. Therefore, the aim of this study was to evaluate and compare the effects of a single session of DRE, IH and CRE on the post-exercise BP and its mechanisms. For this, 49 medicated hypertensive men were randomly allocated to one of 4 experimental sessions: control (70 min of seated rest); DRE (8 exercises, 3 sets of repetitions until moderate fatigue at 50% of 1RM and with 90s of interval between sets and exercises); IH (4 sets, alternated unilateral handgrip, 2 min of isometric contraction at 30% of CVM with 1 min pauses between the sets); and CRE (DRE + IH). In each session, clinic BP and its systemic hemodynamic, autonomic and vascular mechanisms were measured before and after the interventions. Additionally, ambulatory BP was measured for 24h after each session. Data were analyzed with ANOVAs, accepting P <0.05 as significant. As results, DRE decreased clinic BP after its execution, but it did not change ambulatorial BP. Clinic BP reduction after DRE was accompanied by a decrease in stroke volume and an increase in heart rate, cardiac sympathovagal balance and vascular conductance. IH did not promote any reduction in BP after its execution and did not alter any other variable. Similarly to ERD, CRE promoted a significant decrease in clinic BP after its execution without changing ambulatory BP. The reduction in clinic BP after CRE was also accompanied by a decrease in stroke volume and an increase in heart rate and vascular conductance, but sympathovagal balance was not changed. In conclusion, DRE and CRE induce similar clinic PEH accompanied by reduction in stroke volume and increase in heart rate and 9 vascular conductance, while IH does not induce any change in BP and its mechanism after its execution. (AU)

• FAPESP's process: 19/02649-0 - Acute hypotensive effect of dynamic, isometric and combined (dynamic + isometric) resistance exercise in medicated hypertensives men: hemodynamic and autonomic mechanisms
• Grantee: Laura Gomes Oliveira e Silva
• Support Opportunities: Scholarships in Brazil - Master