**2.3 Physical inactivity**

The World Health Oranisation highlighted the fact that one in four adults is not physical active enough across the globe and the challenge of reduced physical activity increases as the income of a country increases [36]. Low physical activity eventually leads to obesity which has gradually increased throughout the past decades both in developing and developed countries. Low rate of atherosclerotic process, including improvement of endothelial dysfunction, low systematic inflammation and stroke that go along with physical activity, could explain the protective role of physical activity on CVDs risk [37]. Numerous epidemiologic studies conducted with non-identical and big populations have demonstrated that physical activity has protective effect on coronary arteries disease. For example, physical activity reduces blood pressure and the prevalence of hypertension by reducing vascular resistance and terminating the action of the sympathetic nervous and the renninangiotensin systems. **Figure 1** shows the possible channels of physical activity that assist in decreasing the likelihood of CVDs. In 41837 women of age group between 55 and 69 years, Folsom et al. [38] study found that hypertension incidence decreased by 10% and 30% in participants with moderate and higher levels of physical activity than those with low levels of physical activity. The biological pathways support the usefulness of physical activity in decreasing the likelihood of stroke including ischemic and hemorrhagic. The possible ramifications on the likelihood of ischemic might be due to the mechanisms that reduce the development of atherosclerotic; while the possible ramifications on the likelihood of hemorrhagic stroke disease might be attributed to low blood pressure as well as additional associated risk factors. Nonetheless, there are conflicting findings from different studies about the relationship of physical activity and the incidence of stroke, with few studies showing relationships or no relationships [39, 40]. These disagreements are likely the result of the type of the study design, population, definition and evaluation of physical activity of the different studies.
