While the researchers behind the 2023 study aren’t entirely sure how certain exercises performed better than others when it came to lowering resting blood pressure, some experts have theories. The study compared isometric exercises — like static weighted leg extensions, isometric hand grips, and wall sits — with other forms of exercise, like aerobic training, resistance training, high intensity interval training (HIIT), and combined training.
As explained by professor of exercise and sports science at the University of New England in Australia, Neil Smart (via WebMD), squeezing your muscles during an isometric exercise constricts the surrounding blood vessels, leading to a reduced blood flow to the area. Holding that squeeze also boosts the presence of oxygen-inhibiting anaerobic metabolites in your system. “The body doesn’t like them [anaerobic metabolites]. As soon as you stop squeezing, blood flow will be normalized and then enhanced in an attempt to clear up this mess that’s been created [in the area],” explained Smart.
The sudden rush of blood flow to the area boosts vasodilation (meaning, it helps dilate your blood vessels). Dilated blood vessels mean smoother flow of blood. This could be how isometric exercises lead to reduced resting blood pressure. Now let’s take a look at how you can do an isometric leg extension, and some other things to consider while doing isometric workouts for blood pressure.