Cardiovascular effects of a strength test (1RM) in prehypertensive subjects

Abstract

Introduction: Physical exercise promotes positive physiological adaptations, reducing the risk of developing cardiovascular diseases and promoting greater autonomic control of heart rate and reduction in pressure levels. Objective: To compare the behavior of arterial pressure and autonomic heart rate modulation in the 1-repetition maximum knee extension test, performed on the 45-degree leg press machine in normotensive and prehypertensive subjects. Methods: Twenty-four male volunteers were assessed. Blood pressure (BP) and heart rate variability (HRV) were evaluated at rest, immediately after the maximum load achieved and during the 10, 20, 30 and 40-minute recovery phases. Statistical analyses were obtained using SigmaStat 3.5 software and a level of significance of 5%. Results: Mean and standard deviation were used to identify 12 normotensive patients (N) aged = 25.5 ± 5.7 years; height = 174.3 ± 6.6 cm; BMI = 24.9 ± 2.4; SBP on average = 112.6 ± 5.6 mmHg and 12 prehypertensive (PH) patients aged = 29.8 ± 6.5 years; height = 175.7 ± 6.7 cm; BMI = 27.8 ± 6.5; mean SBP = 131.1 ± 3.2 mmHg. There was a statistical difference in the pNN50 index (%) at rest (PH = 1.13 ± 0.66 and N = 1.58 ± 0.35) and in the LF/HF index, also at rest (PH = 0.18 ± 0.29 and N = -0.18 ± 0.36). Conclusion: The one-repetition maximum (1RM) test did not promote cardiovascular risk in the prehypertensive group during its execution, with double product results lower than 30,000 mmHg.bpm, demonstrating lower cardiac overload. Moreover, HRV exhibited similarity in sympathetic-vagal behavior, in the time/frequency domain, between the groups. Level of Evidence III; Study Case-control.