Effects of dynamic resistance training, isometric and combined (Dynamic + Isometric) on cardiovascular function and regulation at rest and post-exercise in medicated hypertensive males

Author(s)

Rafael Yokoyama Fécchio

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Escola de Educação Física e Esportes (EEFE/BT)
• Defense date: 2022-06-13

Examining board members

Cláudia Lúcia de Moraes Forjaz; Luiz Aparecido Bortolotto; Raphael Mendes Ritti Dias; Maria Urbana Pinto Brandão Rondon

• Advisor: Cláudia Lúcia de Moraes Forjaz

Abstract

Dynamic resistance training (DRT) reduces blood pressure (BP) and is recommended for hypertension treatment. Although isometric handgrip training (IHT) can also reduce BP, its recommendation for hypertension treatment is still controversial due to gaps in literature. Moreover, a possible additive effect of the association of IHT to TRD in a combined resistance training (CRT) has not been evaluated. Thus, the aim of the present thesis was to evaluate and compare the effects of DRT, IHT and CRT on BP and its mechanisms, in hypertensives. Additionally, the effects of these types of resistance training on the acute BP and its mechanisms responses to the respective resistance exercises were evaluated. For this, medicated hypertensive men were randomly allocated into 4 groups: DRT (n = 16 - 8 exercises, 3 sets to moderate fatigue with 50% of 1RM), IHT (n = 15 - 4 sets of 2 min at 30% of MVC), CRT (n = 15 - DRT followed by IHT) and control (CON n = 16 - 30 min of stretching). Training sessions were conducted 3 times per week for 10 weeks. At the beginning and end of the study, BP (auscultatory) and its systemic hemodynamic (CO2 rebreathing), vascular (brachial duplex ultrasound) and autonomic (spectral analysis of heart rate and BP variability) mechanisms were measured at rest before and after a single resistance exercise session performed with the specific training protocol of each group (DRT, IHT and CRT) or a period of seated rest in the CON group. The effects of training were evaluated by 2-way mixed ANOVAs and by ANCOVAs adjusted to initial values, adopting p < 0.05 as significant. As a result, IHT did not change any variable, while in DRT and CRT, SBP decreased significant and similarly [-8.4 (95%IC -15.9 to -0.8 mmHg), p = 0.023 and -10.7 (95%IC -18.3 to -3.0 mmHg), p = 0.002, respectively] and peak blood flow in reactive hyperemia increased significant and similarly [321 (95%IC 37 to 604 ml/min), p = 0.019 and 296 (95%IC 3 to 589 ml/min), p=0.047, respectively]. Concerning the effects of training on the acute responses to the specific exercise protocols, in general, none of the training regimes modified BP or its mechanisms responses to the respective acute interventions. In conclusion, DRT, but not IHT, reduces BP and improves microvascular function in hypertensives, while the association of IHT to DRT has no additional effect. Moreover, none of the proposed training regimes change the acute cardiovascular responses to one session of the respective exercise protocols (AU)

• FAPESP's process: 18/12390-1 - Effects of dynamic, isometric and combined (dynamic + isometric) resistance training on resting and post-exercise cardiovascular function and regulation in medicated hypertensive men
• Grantee: Rafael Yokoyama Fecchio
• Support Opportunities: Scholarships in Brazil - Doctorate