Get healthy for the sake of getting healthy and you will lose weight as a side effect. That is the primary message of my blog post today. Exercise viewed merely as a vehicle for weight loss is a flawed premise. As the new year is still very young and brimming with resolutions for many people, my initial posts of 2018 will be focused on dispelling the myths underlying common New Years’ resolutions associated with health. In that spirit, I’m going to talk about exercise and its numerous benefits that do not directly pertain to weight loss.
Let’s start by reverse-engineering exercise as a component in heart health and the etiology of cardiac impairments, since how we look standing naked in front of a mirror is rendered quite irrelevant if we can’t keep our ticker ticking! A sedentary lifestyle is one of the 5 major cardiac risk factors, along with high blood pressure, abnormal values for blood lipids, smoking, and obesity. Evidence from numerous clinical and epidemiological studies have clearly shown that reducing the abovementioned risk factors decreases one’s chance of a heart attack or experiencing other cardiac events, such as a stroke, and reduces the possibility of requiring an invasive coronary revascularization procedure, e.g. bypass surgery or coronary angioplasty. Regular exercise has been found to have a favorable effect on many of the established risk factors for cardiovascular disease. For example, exercise promotes weight reduction and can help lower blood pressure, lowering the strain on one’s heart. Exercise can also reduce so-called “bad” cholesterol levels in the blood (LDL in general and VLDL specifically), as well as total cholesterol, although I would posit that reducing systemic inflammation, as identified via a blood marker known as HS-CRP, is an even greater cardiac benefit of exercise, especially aerobic exercise, and can also raise “good” cholesterol (HDL).
Although the isolated effect of an exercise program on reducing any specific risk factor may be relatively small, the cumulative effect of continued moderate exercise on overall cardiovascular disease risk, when combined with other lifestyle modifications such as proper nutrition, smoking cessation and moderating alcohol intake, can be dramatic indeed. There also exist a number of corollary physiological benefits to regular exercise, e.g. improvements in muscular function and the strength of both muscle and bone, as well as a significant improvement in the body’s ability to take in and use oxygen (maximal oxygen consumption or aerobic capacity, aka VO2 max). As one’s ability to transport and use oxygen improves, regular daily activities can be performed with less fatigue, improving overall quality of life, tangential to the reduction of cardiovascular disease risk. This is particularly important for patients with known genetic risk factors and a family history of heart disease whose exercise capacity is markedly lower than that of healthy individuals. There is also a wealth of clinical evidence that long-term exercise training improves the capacity of the blood vessels to dilate in response to vigorous physical activity, consistent with better vascular function and an increased ability to supply oxygen to working muscles.
Individuals with newly diagnosed heart disease who participate in an exercise program report an earlier return to work and improvements in other measures of quality of life, such as self-confidence, lowered stress, and less anxiety. Most importantly, as confirmed by meta-analyses of controlled studies, researchers have found that for heart attack patients who participated in a formal exercise program, the death rate is reduced by a whopping 20% to 25%! This is strong evidence in support of physical activity for patients with heart disease. Although the clear benefits of exercise are unquestionable, it should also be noted as a caveat that exercise programs alone for patients with advanced heart disease, as an independent variable, have not convincingly shown improvement in the heart’s pumping ability or the diameter of the coronary vessels that supply oxygen to the heart muscle due to confounding variables such as the patient’s extent of atherosclerotic plaque accumulation and arterial blockage concomitant with the narrowing of arteries that deliver oxygenated blood throughout the body. If the heart itself does not receive adequate amounts of oxygenated blood during exercise, that in itself can be a risk factor for heart attack, thus cardiac patients should check with their cardiologist first before engaging in vigorous aerobic exercise, which might involve a prudent physician-supervised exercise stress test prior to the commencement of a structured exercise program.