Dose-response curve to exercise in hypertensive individuals: analysis of the number of sessions to the hypotensive effect.
BACKGROUND
The effect of exercise on blood pressure (BP) is already known; however, the dose-response curve of the hypotensive effect of exercise in hypertensive individuals is yet to be clarified.


OBJECTIVE
To evaluate the dose-response curve of the number of sessions that are necessary to cause a hypotensive effect in hypertensive individuals.


METHODS
88 individuals, aged 58 +/- 11 years, divided in Experimental group (EG), with 48 that participated in a physical exercise program (PEP), which consisted of 40 minutes of aerobic exercises performed 3x/week, for 3 months, at 70% of the VO2max, and muscular exercises at 40% of the maximal voluntary contraction (MVC) and Control Group (CG) with 40 individuals that did not participate in the PEP. The systolic (SAP) and diastolic (DAP) arterial pressures were measured before each of the 36 sessions in the EG and assessed by ambulatory blood pressure monitoring (ABPM) in the CG. Differences in BP, the variation rate (D%) and the maximum hypotensive effect (MHE%) were observed between sessions. The data were expressed as means +/- SD; the t test and correlation were used, with p<0.05 being considered significant.


RESULTS
There was no difference regarding BP values in the CG. The EG showed an important decrease of 15 mmHg in SAP and 7 mmHg in DAP, with a large part of this effect occurring as early as the first session and the majority up to the 5th session. There was a strong inverse correlation (R:-0.66) with the number of sessions.


CONCLUSION
An important hypotensive effect was observed from the 1st session on and it was observed that the dose-response curve can be abrupt and decrescent, instead of flat.