If you currently get regular physical activity, congratulations! But if you’re not yet getting all the activity you need, you have lots of company. According to the Centers for Disease Control and Prevention (CDC), 60 percent of Americans are not meeting the recommended levels of physical activity. Fully 16 percent of Americans are not active at all. Overall, women tend to be less active than men, and older people are less likely to get regular physical activity than younger individuals. What does it mean to get “regular physical activity?” To reduce the risk of heart disease, adults need only do about 30 minutes of moderate activity on most, and preferably all, days of the week. This level of activity can also lower your chances of having a stroke, colon cancer, high blood pressure, diabetes, and other medical problems.
If you’re also trying to manage your weight and prevent gradual, unhealthy weight gain, try to get 60 minutes of moderate- to vigorous-intensity activity on most days of the week. At the same time, watch your calories. Take in only enough calories to maintain your weight. Those who are trying to keep weight off should aim a bit higher: Try to get 60–90 minutes of moderate-intensity activity daily, without taking in extra calories. Later in the book, you’ll find out more about the types of activities that you can easily fit into your routine, as well as ways to break up your activity time into manageable segments.
If you’re not as active as you might be, take a moment to consider why. Maybe you’re just in the habit of traveling by car or bus, even when you’re not going far. In your free time, perhaps it’s tempting to sit down in front of the TV or computer rather than do something more vigorous. It’s easy to get busy or tired and decide that it’s just simpler to put off that brisk walk or bike ride. But when you think about the serious problems that physical inactivity can create for your health—and the enormous rewards of getting regular activity—you may want to reconsider. Let’s start with the ways that physical activity affects your heart
The Heart Connection
It’s worth repeating: Physical inactivity greatly increases your risk of developing heart disease. Heart disease occurs when the arteries that supply blood to the heart muscle become hardened and narrowed, due to a buildup of plaque on the arteries’ inner walls. Plaque is the accumulation of fat, cholesterol, and other substances. As plaque continues to build up in the arteries, blood flow to the heart is reduced. Heart disease can lead to a heart attack. A heart attack happens when a cholesterol-rich plaque bursts and releases its contents into the bloodstream. This causes a blood clot to form over the plaque, totally blocking blood flow through the artery and preventing vital oxygen and nutrients from getting to the heart.
A heart attack can cause permanent damage to the heart muscle. Some people aren’t too concerned about heart disease because they think it can be cured with surgery. This is a myth. Heart disease is a lifelong condition. It’s true that certain procedures can help blood and oxygen flow more easily to the heart. But the arteries remain damaged, which means you are still more likely to have a heart attack. What’s more, the condition of your blood vessels will steadily worsen unless you make changes in your daily habits and control other factors that increase risk. Heart disease is a serious disease—and too often, a fatal one. It is the number one killer of Americans, with 500,000 people in the United States dying of heart disease each year. Many others with heart problems become permanently disabled. That’s why it’s so vital to take action to prevent this disease. Getting regular physical activity should be part of everyone’s heart disease prevention program.
Heart Disease Risk Factors
Risk factors are conditions or habits that make a person more likely to develop a disease. They can also increase the chances that an existing disease will get worse. Certain risk factors for heart disease, such as getting older or having a family history of early heart disease, can’t be changed. But physical inactivity is a major risk factor for heart disease that you have control over. You can make a decision to get regular physical activity, and this booklet can help you create a workable, enjoyable program that will help you protect your heart.
Other major risk factors for heart disease that you can change are smoking, high blood pressure, high blood cholesterol, overweight, and diabetes. Every risk factor counts. Research shows that each individual risk factor greatly increases the chances of developing heart disease and having a heart attack. A damaged heart can damage your life, by interfering with enjoyable activities and even keeping you from doing simple things, such as taking a walk or climbing steps. But it’s important to know that you have a lot of power to protect your heart health.
Getting regular physical activity is an especially important part of your healthy heart program, because physical activity both directly reduces your heart disease risk and reduces your chances of developing other risk factors for heart disease. For example, regular physical activity may reduce LDL (bad) cholesterol, increase HDL (good) cholesterol, and lower high blood pressure. It can also protect your heart by helping to prevent and control diabetes. Finally, physical activity can help you to lose excess weight or stay at your desirable weight, which will also help to lower your risk of heart disease.
The Calorie Connection
One way that regular physical activity protects against heart disease is by burning extra calories, which helps you to lose excess weight or stay at your desirable weight. To understand how physical activity affects calories, it is helpful to consider the concept of “energy balance.” Energy balance is the amount of calories you take in relative to the amount of calories you burn. Per week, you need to burn off about 3,500 more calories than you take in to lose 1 pound.
If you need to lose weight for your health, regular physical activity can help you through one of two approaches. First, you can choose to eat your usual amount of calories, but be more active. For example, a 200-pound person who keeps on eating the same amount of calories, but begins to walk briskly each day for 11/2 miles, will lose about 14 pounds in 1 year. Staying active will also help to keep the weight off. Second, you can eat fewer calories and be more active. This is the best way to lose weight, since you’re more likely to be successful by combining a healthful, lower-calorie diet with physical activity. For example, a 200-pound person who consumes 250 fewer calories per day, and begins to walk briskly each day for 11/2 miles, will lose about 40 pounds in 1 year.
Most of the energy you burn each day—about three quarters of it—goes to activities that your body automatically engages in for survival, such as breathing, sleeping, and digesting food. The part of your energy output that you control is daily physical activity. Any activity you take part in beyond your body’s automatic activities will burn extra calories. Even seated activities, such as using the computer or watching TV, will burn calories—but only a very small number. That’s why it’s important to make time each day for moderate-tovigorous physical activity.