They found that 12 weeks of swimming significantly lowered blood pressure and improved the function of arteries in a group of sedentary, unmedicated over-50s whose blood pressure was on the verge of "unhealthy" (prehypertension) or in stage 1 of hypertension.
For their study, Dr Nantinee Nualnim, of UT's Cardiovascular Aging Research Laboratory, and colleagues, recruited 43 sedentary people aged over 50 (average age of 60) who also had prehypertension or stage 1 hypertension but were not on any medication.
They randomly assigned them either to do 12 weeks of swimming or 12 weeks of gentle relaxation exercises (the controls).