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 you 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.
Exploding the Myths
Even when you know physical activity is good for you, it’s easy to keep dragging your feet—literally. We all have reasons to stay inactive, but sometimes those reasons are based more on myth than reality. Here are some of the most common myths about physical activity and ways to replace them with a more realistic, can-do spirit.
Myth 1: “Physical activity takes too much time.”
Physical activity does take some time, but there are ways to make it manageable. If you don’t have 30 minutes in your daily schedule for an activity break, try to find three 10-minute periods. If you’re aiming for 60 minutes daily—a good goal if you’re trying to avoid weight gain—perhaps you can carve out some “fitness time” early in the day, before your schedule gets too busy. Another idea is to combine physical activity with a task that’s already part of your daily routine, such as walking the dog or doing yard chores.
Myth 2: “Getting in shape makes you tired.”
Once you begin regular physical activity, you’re likely to have even more energy than before. As you progress, daily tasks will seem easier. Regular, moderate-to-brisk physical activity can also help you to reduce fatigue and manage stress.
Myth 3: “The older you are, the less physical activity you need.”
Most people become less physically active as they age, but keeping fit is important throughout life. Regular physical activity increases older people’s ability to perform routine daily tasks and to stay independent longer. No matter what your age, you can find a physical activity program that is tailored to your particular fitness level and needs.
Myth 4: “Taking medication interferes with physical activity.”
In most cases, this is not true. In fact, becoming more active may lessen your need for certain medicines, such as high blood pressure drugs. However, before beginning a physical activity program, be sure to inform your doctor about both prescription and over-the counter medications you are taking, so that your health can be properly monitored.
Myth 5: “You have to be athletic to exercise.”
Most physical activities don’t require any special athletic skills. In fact, many people who have bad memories of difficult school sports have discovered a whole world of enjoyable, healthful activities that involve no special talent or training. A perfect example is brisk walking—a superb, heart healthy activity. Others include bicycling, gardening, or yard work, as long as they’re done at a brisk pace. Just do more of the activities you already like and already know how to do. It’s that simple.
Only those who risk going too far can possibly find out how far one can go.