It may seem paradoxical, but the truth is that Raising the heart rate when you suffer from hypertension doing sports is not harmful. In fact, physical exercise helps reduce blood pressure levels, improves fitness and reduces risk factors that cause chronic diseases. Of course, not all types of physical activity contribute the same. The mechanisms that relate the decrease in blood pressure to aerobic exercise (such as running, swimming or cycling) are well studied, but little research has been done on the effects of resistance exercise in hypertension.
At first, we might think that this modality could be harmful. However, it has long been known that is a therapeutic option for high blood pressure. What was not clear until now is what guidelines must be followed for strength training to be beneficial for treating hypertension. Hence the importance of a study recently published in the journal Scientific Reports and that determines what is the best way to carry it out.
It should be noted that cardiovascular diseases are already the leading cause of death worldwide. Specific, arterial hypertension is responsible for 13.8% of deaths of this type. This condition is diagnosed when the systolic blood pressure exceeds 140 millimeters of mercury (mmHg) and/or the diastolic blood pressure exceeds 90 mmHg. It is a multifactorial disorder triggered by problems such as an unhealthy diet, excessive alcohol consumption, smoking, and a sedentary lifestyle.
The study in question has been carried out by the State University of São Paulo (UNESP), in Brazil. Through this work it has been shown that strength training practiced at moderate to vigorous intensity two to three times per week it is an effective way to mitigate high blood pressure.
Directed by Giovana Rampazzo Teixeira, professor of the Physical Education Department of UNESP in Presidente Prudente, the group reviewed more than 21,000 scientific articles and conducted a meta-analysis Cochrane, considered the gold standard of systematic reviews. According to the authors, the analysis focused on the effects of variables such as age, dose-response training, load, volume, and frequency.
Stress remained lower for 14 weeks after the end of exercise
In this study, the sample consisted of 253 hypertensive subjects with a mean age of 59.66 years. The meta-analysis focused on baseline and post-training hypertension responses in controlled studies evaluating the effects of training for eight weeks or longer.
“We were primarily interested in the volume and intensity that were considered sufficient to achieve a significant reduction in blood pressure. On average, eight to ten weeks of strength training led to a reduction 10 mmHg in systolic pressure and 4.79 mmHg in diastolic pressure”, Teixeira declares to the São Paulo Research Foundation Agency (FAPESP).
The study showed that the effective results appeared around the twentieth session of training. Blood pressure remained lower for about 14 weeks after the training ended. “In clinical practice and in gyms or fitness centers, strength training may be a treatment option for people with arterial hypertension as a non-pharmacological intervention, provided that the key variables are sufficiently known and the objectives are taken into account. of the subject”, explains Teixeira.
For hypertension, a moderate to vigorous intensity is best
This study is innovative for having gathered additional evidence on the influence of age, load, intensity and frequency of exercise. After excluding 21,035 articles that did not meet the review objectives, the investigators left 54 articles for full-text analysis. Fourteen were considered relevant for inclusion in the systematic review. The results of the analysis showed that strength training was more effective to reduce blood pressure in protocols with a load intensity of moderate to vigorous, a frequency of at least twice a week and a minimum duration of eight weeks.
Moderate to vigorous loading intensity was defined as more than 60% of the heaviest weight the subjects could lift a single time known as the one repetition maximum, or 1RM, so for a 10kg 1RM, the most effective training load would be over 6kg.
A subgroup analysis revealed more about the influence of age on the effects of resistance training than lowered blood pressure significantly more in the 18-50 age group than in the 51 to 70 year old. “In any case, strength training can be done at any age. The effect on blood pressure is also beneficial in older people,” Texeira said.
For a long time, only aerobic training was prescribed to treat high blood pressure, and molecular studies focused almost exclusively on the effects of this type of exercise. “Strength Training was recently included in the Brazilian guidelines on the treatment of arterial hypertension but much more research is needed to get stronger evidence,” adds the professor.
Thus, according to her, future studies should investigate the cellular and molecular mechanisms responsible for the decrease in blood pressure in response to strength training. For the time being, current knowledge shows that increases heart rate, increases nitrous oxide production, which promotes vasodilation by expanding the diameter of blood vessels, and boosts blood flow.
In the long term, it facilitates adaptations, such as a lower heart rate at rest, lower blood pressure, increased cardiac efficiency and increased VO2max, which is the maximum rate of oxygen consumption achievable during vigorous exercise. Usually measured in milliliters of oxygen consumed per kilogram of body weight per minute (ml/kg/min), VO2max is relevant to cardiovascular health.
Between the limitations of the analysis pointed out by the authors The inclusion of patients taking antihypertensive medication, such as beta-blockers, diuretics, calcium antagonists, and angiotensin-converting enzyme (ACE) inhibitors, was found in 11 of the 14 studies. Furthermore, in some studies the inclusion of men and women in the same group precluded a gender-sensitive analysis of the effects of resistance training.