The study found that a 12-week program combining aerobic exercise, strength training, and flexibility training, delivered by trained community health workers, was significantly more effective than a control group receiving no intervention. **Key findings:**
* **Improved cardiovascular health:** The intervention group showed significant reductions in blood pressure and waist circumference, indicating improved cardiovascular health. * **Reduced arterial stiffness:** The intervention group experienced a significant decrease in arterial stiffness, a key indicator of cardiovascular risk.
The other protocols tested were RT alone, and moderate-intensity aerobic training combined with RT. The study was conducted in Brazil with FAPESP’s support at São Paulo State University’s School of Sciences (FC-UNESP) in Bauru. The volunteers performed the exercise programs twice a week for nine months at four neighborhood community centers run by an NGO. Clinical status, anthropometric measurements and specific health parameters (cardiovascular, functional, mobility etc.) were assessed before the first session (baseline), at the end of the nine-month intervention, and three months after that. HIIT combined with RT and moderate-intensity aerobic training combined with RT were equally efficacious in terms of reducing waist circumference (by 3.3 cm on average). This benefit persisted after the end of the training period. However, only HIIT combined with RT effectively lowered systolic blood pressure (7.9 mmHg) and reduced arterial stiffness (0.69 m/s), which remained so three months after the end of the training period.
All three programs were efficacious in terms of improved functional performance (handgrip, flexibility, lower limb strength and mobility), but only HIIT combined with RT at least partially maintained the improvements after the intervention. “The lack of improvement in cardiovascular parameters for the groups that performed RT alone or moderate-intensity aerobic training combined with RT suggests that HIIT was responsible for the improvement in blood pressure and arterial stiffness. The superiority of HIIT may have been due, at least to some extent, to the need for constant adjustment of blood vessels during interval training,” Emmanuel Ciolac, a professor at FC-UNESP and last author of the article, told Agência FAPESP.
During HIIT, heart rate and stroke volume (the volume of blood pumped out of the heart during each systolic contraction) increase, Ciolac explained. The rise is normally proportional to the intensity of the exercise. Arteries and smaller blood vessels expand to receive the augmented blood flow (vasodilation), contracting again while the body recovers and the blood flow decreases. “Our hypothesis is that the primary mechanism behind the improvement in arterial stiffness is associated with this constant adjustment of blood vessels and the increase or decrease in production of vasodilatory substances during bursts of exercise alternating with recovery,” he said. Public policy
The study’s findings offer a clear message: low-income older women who participate in an affordable exercise program will experience significant benefits for their cardiovascular health. This message is particularly important given the high prevalence of cardiovascular diseases among this demographic. The researchers are confident that their findings will have a significant impact on public policy relating to the prevention of cardiovascular diseases.
Arterial stiffness tends to increase the risk of cardiovascular disease. “A reduction of 7 mmHg in systolic pressure is very substantial and considerably lowers the risk of having a heart attack or stroke. Arterial stiffness is the main marker of vascular aging and a very important variable in abnormally high systolic pressure,” he explained. Previous studies by his group showed that HIIT has no risks for people with high blood pressure, obesity or diabetes, or indeed for clinical populations in general. “The protocol requires a prior assessment to confirm the absence of contraindications, such as a high risk of heart attack, for example. Generally speaking, it’s very safe,” Ciolac stressed.
* **Mission:** To support scientific research in all fields of knowledge. * **Funding:** Provides scholarships, fellowships, and grants to researchers. * **Target Audience:** Investigators linked with higher education and research institutions in the State of São Paulo, Brazil.
