Effect of the number of sets on acute cardiovascular responses during stretching exercise

Abstract

Few studies have investigated the effects of manipulating variables of stretching exercise prescription on acute cardiovascular responses. The objective of this study was to compare the acute responses of heart rate, blood pressure and double product before, during and after four sets of passive static stretching during unilateral hip flexion. The sample consisted of 16 adult men aged 18 to 27 years (22±2.8 years) with no experience in flexibility training. The cardiovascular variables were measured by photoplethysmography with continuous recording for 5 minutes at rest, during exercise and 10 minutes after stretching. A difference was observed in all variables (p<0.05) when resting and post-exercise values were compared to exercise values. There was only an increase in blood pressure values between sets. Systolic blood pressure was increased in the third set compared to the first [set 1 = 136 mmHg (±9.4); set 3 = 145 mmHg (±9.7)] and diastolic blood pressure was increased in the second set compared to the first [set 1 = 79 mmHg (±6.7); set 2 = 84 mmHg (±9.1)]. Hypotension was not observed post-exercise. It was concluded that the stretching sets have a cumulative effect on systolic and diastolic blood pressure responses, but not on heart rate. However, the stretching protocol produced no hypotensive effect after exercise.