The objective of this study is to analyze the effects of isometric handgrip exercise on arterial pressure and on the autonomic cardiac modulation of hypertensive individuals treated in the Unified Health System (UHS). Two prospective, randomized, controlled trials will be conducted with hypertensive patients in the public health network of Petrolina (PE) and São Paulo (SP). Included in the study will be individuals with an age group over 18 years of both genders, with systemic arterial hypertension (SAH) controlled with the use of antihypertensive medication, non-smokers and without the presence of diabetes or other cardiovascular diseases that will be allocated randomly in two groups: supervised group (SG) and control group (CG). SG will be instructed to perform supervised isometric handgrip exercise for three weekly sessions in four sets with two minutes of isometric contraction with 30% of maximal voluntary contraction (MVC) of the subjects and interval between two-minute series. In CG, individuals will be encouraged to increase their level of physical activity. Prior to initiation and after 12 weeks of intervention, blood pressure, autonomic cardiac modulation and level of physical activity will be obtained.