The researchers conducted an eight week exercise intervention study on 207 untreated hypertensive patients. They divided the patients into five groups according to the length of exercise each week. The weekly exercise time of these groups was: no exercise, 30 to 60 minutes, 61 to 90 minutes, 91 to 120 minutes, and more than 120 minutes.
At the beginning of the study, there were no differences among the groups in terms of age, gender, height, weight, calorie intake and blood pressure. Over time, the researchers found no change in blood pressure in the non exercise group. However, all other exercise group members showed a significant decrease in systolic (high) and diastolic (low) blood pressure. From the point of view of antihypertensive effect, the group exercising 61 minutes to 90 minutes a week is more obvious than that of the group exercising 30 minutes to 60 minutes a week.
At the same time, the results also showed that increasing exercise time on the basis of 61 to 90 minutes of exercise per week did not cause a further significant drop in blood pressure. The average exercise time in the 61 to 90 minute group was 75 minutes a week, with an average systolic blood pressure drop of 12 mmHg and a diastolic blood pressure drop of 8 mmHg. There was no significant difference in diastolic blood pressure among exercise groups.
In addition, the study also showed no significant association between the frequency of weekly exercise and the drop in blood pressure. Therefore, the researchers suggest that patients with hypertension should spend 30 to 60 minutes a week doing exercises like aerobics. However, other recent studies have shown that even an hour of exercise a week can halve the risk of cardiovascular disease.
The researchers say their findings show that it's possible to reduce blood pressure with less time. At the same time, they pointed out that although 30 to 60 minutes of exercise a week is enough to have an impact on blood pressure, more exercise than that amount depends on the extent of cardiovascular disease in the exerciser. If patients don't know how much exercise they should do, they may as well ask a doctor familiar with their condition to determine their frequency and intensity of exercise according to their suggestions.