Final answer:
Moderate physical activity reduces the risk of cardiovascular disease by enhancing cardiac efficiency and lowering cholesterol levels. Exercise increases the heart's stroke volume and decreases LDL cholesterol, which reduces arterial plaque and blood pressure. It also offers other health benefits like weight maintenance and improved mental health.
Step-by-step explanation:
Research has shown that moderate physical activity reduces the chance of cardiovascular disease principally by improving cardiac efficiency and lowering cholesterol. Firstly, regular exercise results in a larger heart size in athletes compared to nonathletes, which increases stroke volume and allows the heart to deliver the same amount of blood with a lower heart rate, thereby reducing stress on the heart.
Secondly, exercise lowers cholesterol levels by removing low-density lipoproteins (LDLs) from circulation, which are associated with an increased risk of cardiovascular disease. These activities contribute to decreased rate of plaque formation in arteries and can result in reduced blood pressure.
Moreover, beneficial impacts of exercise include the improvement of insulin sensitivity, increase in high-density lipoproteins (HDLs or 'good' cholesterol), and enhancement of the mechanical efficiency of the heart. Exercise also supports weight maintenance, strengthens muscles, increases bone density, improves cognitive function, and has been found to have a role in the treatment of mild-to-moderate depression. Overall, even as little as 30 minutes of noncontinuous exercise daily can have significant health benefits, including a nearly 50 percent reduction in heart attack rates.