High blood pressure is responsible for 13.8% of deaths caused by cardiovascular diseases, which are the primary cause of death globally.
When systolic blood pressure surpasses 140 millimeters of mercury (mmHg) and/or diastolic pressure surpasses 90 mmHg, it is diagnosed as arterial hypertension. This condition is multifactorial, caused by factors such as an unhealthy diet, excessive alcohol consumption, smoking, and a sedentary lifestyle.
Although strength training has been considered a therapeutic option for a long time, the most effective protocols remain unclear.
For this study, the sample consisted of 253 hypertensive individuals, with a mean age of 59.66. The meta-analysis examined controlled studies that evaluated the effects of training lasting eight weeks or longer on baseline and post-training hypertension responses.
The findings, published in Scientific Reports, indicated that significant improvements were observed after approximately twenty training sessions. Blood pressure remained lowered for around 14 weeks after the conclusion of the training program.
For a long time, aerobic training was the recommended exercise for treating high blood pressure, and molecular studies predominantly analyzed its effects.
The systematic review looked at a total of 21,132 scientific articles to find strong evidence of how strength training affects HBP. Earlier research on the subject had uncovered similar findings, but the present investigation was unique as it gathered new information about the factors of age, load, intensity, and frequency.
A total of 21,035 articles were eliminated because they were deemed irrelevant to the review’s aims. Of the remaining 97 articles, 43 were eliminated due to duplicate content, leaving 54 articles for full-text examination. Fourteen met the inclusion criteria for the systematic review.
The analysis’s findings revealed that strength training programs with moderate to high load intensity, a frequency of at least twice per week, and a minimum length of eight weeks were most successful in lowering blood pressure.
To qualify as moderate to vigorous load intensity, the weight lifted had to be more than 60% of the one-repetition maximum (1RM), which is the heaviest weight that a person can lift just once. For instance, if the 1RM is 10 kg, the most effective training load would be more than 6 kg.
The majority of the study samples were aged between 60 and 68 years, with only two being younger (18-46 years). Seven studies included both male and female participants, seven involved only female participants, and one consisted exclusively of male participants.
An examination of subgroups provided further insight into the impact of age on the effects of strength training. The findings indicated that strength training significantly reduced blood pressure more in the 18-50 age group than in the 51-70 age group.
“In any event, strength training can be practiced at any age. The effect on blood pressure is beneficial in older people, too,” said the lead author.
Subsequent studies should explore the cellular and molecular mechanisms that account for the reduction of blood pressure in response to strength training.
Presently, the prevailing understanding indicates that strength training elevates heart rate, stimulates the production of nitrous oxide, which causes vasodilation by widening blood vessels, and enhances blood flow.
In the long run, it facilitates adaptations such as a lower resting heart rate, lower blood pressure, improved heart efficiency, and higher VO2max, which refers to the maximum rate of oxygen consumption that can be achieved during strenuous exercise.
VO2max, typically assessed in milliliters of oxygen consumed per kilogram of body weight per minute (mL/kg/min), holds relevance for cardiovascular well-being.
The authors acknowledged several limitations of the analysis, including the incorporation of participants taking antihypertensive medication such as beta-blockers, diuretics, calcium channel blockers, and angiotensin-converting enzyme (ACE) inhibitors in 11 of the 14 studies.
Additionally, certain studies failed to conduct gender-specific analyses of the impacts of strength training due to the inclusion of both men and women in the same group.
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