Effects of a single session of isometric handgrip exercise on blood pressure in hypertensive women: a randomized crossover trial

Background : While there are consistent chronic reductions in blood pressure following an extended period of isometric training, the acute effects exhibit notable variation. These results suggest potential variability in individual responses to exercise, emphasizing the need to investigate whether various factors, such as age, medications, among others, can account for these diverse responses. Aim: The aims of this study were to analyze acute blood pressure responses after isometric handgrip exercise and to identify factors associated with responsiveness in hypertensive women. Methods: 18 medicated hypertensive women were randomly allocated to perform two experimental sessions: Handgrip (4[two on each arm] x 2-min set at 30% of their maximal voluntary contraction) or Sham (the same protocol as the handgrip session, but with an anti-stress ball, without any isometric component). Pre-and post-interventions (Post 15’, Post30’, Post45’ and Post60’) resting blood pressure was evaluated. Average and interindividual responses for handgrip session were analyzed, while the linear regression was used to identify factors associated with responsiveness. Results: No significant changes were observed in systolic and diastolic blood pressure after both the Handgrip and Sham sessions (p>0.05). Interindividual variation was 3.6 mmHg for systolic blood pressure and 1.6 mmHg for diastolic blood pressure. Half of hypertensive women experienced a reduction in systolic blood pressure above 4 mmHg. Age, body mass index, pre-intervention blood pressure, and medications were not found to be predictors of these responses (p>0.05). Conclusion : Isometric handgrip exercise did not reduce blood pressure reduction in hypertensive women, although 50% reduced systolic blood pressure.