Your first line of defense against heart problems is a physical training program. Regular exercise keeps your blood vessels flexible so they can dilate in response to stressors. Exercise also helps prevent obesity, which puts extra strain on the heart and is a key contributor to high blood pressure. It also makes the heart more efficient, so that more blood is being ejected from the heart with each beat.
How does this happen?
Exercise increases the size of the heart, growing the left ventricle cavity that pumps blood. Because each contraction is more powerful and more oxygenated blood reaches your brain and muscles, heart rate is reduced. A related adaptation is an increase in parasympathetic nervous system activity (known as the “rest and digest” system) so that you experience less stress and better sleep.
Most people think of endurance exercise as their go-to for cardio, and it is a viable option as long as you work at a vigorous pace and do it often enough—30 minutes most days of the week at a moderate effort, such as brisk walking of hills. For people who are crunched for time or want more variety in their training, intervals may be a better option.
Research has found that interval training is equally as effective as continuous endurance training for improving the body’s ability to use oxygen (the primary way we measure cardiovascular function during exercise) and it conveys additional benefits not seen with endurance exercise such as lower insulin levels and better metabolism.
Strength training is also important because it improves function of the endothelium, the inner lining of the blood vessels that is involved in releasing nitric oxide for dilation and constriction of vessels. Strength training also helps regulate body weight, and when combined with conditioning, it enhances aerobic capacity and resistance to fatigue.