There doesn't really seem to be anything unique to single out tai chi in particular in this study. The benefits pointed out in the article --- that it's meditative, encourages stretching and relaxation, improves balance --- seem to also be associated with things like yoga, or just going through a general stretching and mobility routine. They idea that calming yourself (removing stress or just relaxing) will lower your blood pressure is so intuitive to most people that we say someone needs to calm down or "they'll blow a gasket."<p>The contrast with "vigorous aerobic exercises" is also interesting. The study looked at<p>> "Aerobic exercise interventions included climbing stairs, jogging, brisk walking, and cycling. Exercise intensity in the aerobic exercise group was monitored. The maximum heart rate was estimated as 208 − (0.7 × age in years)."<p>which makes you wonder how much the findings compare to the well known benefits of zone-2 HR aerobic training. "Vigorous" is a bit of weird term that suggests very different things between different people. Low HR cardio is usually not considered "vigorous" at all.<p>Another broader question would be whether maximizing lowered blood pressure is more important than getting people doing "vigorous" aerobic exercise, which brings a whole host of important benefits along with lowering blood pressure. Most people should get a lot more aerobic exercise and use relaxation methods, but I would probably recommend aerobic exercise first.