How does exercise benefit heart health?

By: Ogechi Obi, Freelance Health Writer and Datelinehealth Africa Volunteer, with medical review and editorial support from the DLHA Team.

Exercise benefits heart health in the ways discussed below and summarised in Table 1.

• Body weight reduction

Body weight and body fat are among the risk factors for heart disease. 

Your risk of cardiovascular diseases increases with increasing body mass index (BMI) and waist circumference – more than 35 inches for women or more than 40 inches for men. 

The ideal body weight is 18.5 and 24.9 kg/m².

Excessive weight can cause buildup of fatty deposits in blood vessels and increase blood pressure. It also increases the workload of the heart as it pumps blood to an overweight and obese body. 

Physical activity helps to support the maintenance of body weight once weight is lost through other additional means like a healthy diet. This in turn reduces the odds of you developing diabetes and hypertension and their resultant effect on the heart. Exercise combined with a healthy weight therefore contributes to improving your heart health. 

A large population based study ⁽⁸⁾ indeed confirmed this viewpoint as it showed that being physically active provided clear benefits to heart health in people who maintain a healthy weight than in those who are overweight or obese. 

You should therefore aim at weight loss, which can be achieved effectively with exercise combined with a good diet plan. 

• Lowers high blood pressure

A high blood pressure is one of the important risk factors for cardiovascular diseases and is mostly associated with no symptoms. 

This means that you may be unaware that you have high blood pressure and consequently be silently at risk for serious cardiovascular diseases, including stroke and heart disease. 

Moderate to high intensity exercise can help to lower and prevent rise in your blood pressure. 

Researchers have proposed various mechanisms through which physical activity prevents hypertension. 

A study ⁽⁷⁾ showed that in a healthy person, exercise training causes a general adjustment of the arterial wall and improves its elasticity. In so doing, arterial vessel resistance drops and so does blood pressure. 

Exercise also alters

• the effectiveness of insulin on tissues of the body, 

• autonomic nervous system function, 

• blood vessel constriction regulation, and 

• reduction in arterial stiffness 

There is a mean reduction of 3.2 mm Hg in systolic blood pressure and 1.8 mm Hg in diastolic blood pressure over 24 hours following physical activity. 

It has also been shown that a 2 mm Hg decrease in systolic blood pressure can reduce the risk of coronary heart disease by 4% and a 5 mmHg reduction will likely reduce it by 9%. 

A study that examined ⁽²⁾ 65 independent studies on the association between blood exercise and blood pressure, found that exercise has a significant blood pressure-reducing effect particularly in physically active male individuals, and those not taking antihypertensive medications.

• Raising “good” cholesterol levels

A buildup of cholesterol deposits can occlude the blood vessels and prevent blood flow, thereby increasing the risk of coronary heart disease and heart attack. 

Cholesterol is transported throughout the body by lipoproteins – low-density lipoprotein (LDL) called the bad cholesterol and high-density lipoprotein (HDL) called the good cholesterol. 

While LDL cholesterol can build up and form plaques in the blood, HDL helps in absorbing and transporting cholesterol to the liver for it to be removed from the body. 

Exercise improves the level of high-density lipoprotein cholesterol. 

A Mediterranean cohort study ⁽⁶⁾ found that physically active women had a more pronounced increase in HDL cholesterol than their sedentary counterparts. In men with low HDL and high triglyceride concentrations, regular endurance exercise ⁽³⁾ significantly improved their HDL cholesterol levels. 

On the other hand, reductions in LDL cholesterol levels were  shown to decrease the incidence of heart attacks in 170,000 participants in a randomized trial. ⁽¹⁾ A randomized trial produces a more reliable level of evidence as it is a study that divides subjects or participants by chance into separate groups in order to compare different treatments or interventions.

For good heart health, it is important to maintain a good lipid profile, and regular moderate intensity exercise does help you to achieve “good” cholesterol levels in the blood.

• Lowers blood sugar levels and the risk of Diabetes Mellitus

People with diabetes are more likely to develop heart disease. 

Apart from damaging the nerves and blood vessels, high blood sugar can increase your risk of developing high blood pressure, high cholesterol deposits, and other risk factors for cardiovascular diseases. 

Exercise lowers blood sugar levels by improving the body’s sensitivity to insulin, which controls the glucose level. 

During physical activity, the sugar level reduces because the muscles utilize and burn glucose for energy. Additionally, exercise lowers your glycosylated hemoglobin values (i.e HbA1c) - a good indicator of reduced blood glucose levels.

There is a negative relationship between physical activity and the incidence of type 2 diabetes. 

Increasing your physical activity level improves your heart health by lowering your risk of developing diabetes, which is a major risk factor for cardiovascular disease. This is also achieved even in high-risk women with a history of gestational diabetes. ⁽⁹⁾