Acute Blood Pressure Response to Different Types of Isometric Exercise: A Systematic Review with Meta-Analysis

Background: This study aimed to identify the blood pressure (BP) responses during different types of isometric exercises (IE) in adults and to evaluate whether BP responses according to IE is influenced by the characteristics of participants and exercise protocols. Methods: The search was conducted in PubMed, Cochrane Central, SPORTDiscus, and LILACS databases in June 2020. Random effects models with a 95% confidence interval and p < 0.05 were used in the analyses. Results: Initially, 3201 articles were found and, finally, 102 studies were included in this systematic review, seven of which were included in the meta-analysis comparing handgrip to other IE. Two -knee extension and deadlift promoted greater increases in systolic (+9.8 mmHg; p = 0.017; I2 = 74.5% and +26.8 mmHg; p < 0.001; I2 = 0%, respectively) and diastolic (+7.9 mmHg; p = 0.022; I2 = 68.6% and +12.4 mmHg; p < 0.001; I2 = 36.3%, respectively) BP compared to handgrip. Men, middle-aged/elderly adults, hypertensive individuals, and protocols with higher intensities potentiate the BP responses to handgrip exercise (p < 0.001). Conclusions: IE involving larger muscle groups elicit greater BP responses than those involving smaller muscle masses, especially in men, middle-aged/elderly adults and hypertensive individuals. Future studies should directly compare BP responses during various types of IE in different populations.