Fitness

Exercise may be aerobic or anaerobic. Aerobic exercise requires oxygen to ensure that there is enough energy for exercise to continue. Anaerobic exercise is of short duration and depends on stored energy sources instead of oxygen. Aerobic exercise, such as running, swimming, or dancing, improves your cardiovascular system (your heart and blood vessels). Exercises for improving muscle strength and flexibility are examples of anaerobic exercise.

During aerobic exercise, which involves continuous activity, your lungs work harder to bring in more oxygen and your heart pumps harder to send blood to the muscles. This process strengthens your lungs, heart, and muscles, thus improving overall conditioning and endurance.

Anaerobic exercise can be healthy, too, but does little to improve the health of your heart. Lifting weights and stop- and-start sports (such as tennis, racquetball, and soccer) increase the heart rate and strengthen certain muscles. However, these exercises usually are too short in duration to give you enough aerobic conditioning to strengthen your heart and lungs.

Aerobic exercises that increase cardiovascular fitness include:

• walking briskly

• swimming

• running

• jogging

• climbing stairs

• using a stationary bicycle

• bicycling

• vigorous dancing

• ice skating or roller skating

• aerobics, regular or low impact

• cross-country skiing

• rowing.

Exercises performed at low and moderate intensity will help you stay fit and healthy. You do not need to exercise strenuously to improve your health. For example, regular, moderate activity, such as three 10-minute walks a day, reduces your risk of death by disease by as much as 60%.

Before beginning an exercise program, consider the following questions:

• What physical activities do you enjoy?

• Do you prefer group or individual activities?

• What kind of program best fits your schedule?

• Do you have any physical conditions that limit your choice of exercise program? For example, if you have arthritis, exercise is an important part of the overall treatment. Ask your doctor about ways to exercise, including range-of-motion exercises.

Try to build up to 30 minutes of exercise a day on most days each week. Thirty-minute workouts are good for cardiovascular health.

Warm-Up and Cool-Down Exercises

Any exercise program should include warm-up and cool-down exercises to do before and after aerobic conditioning. Muscles that have not been used are cool. Stretching and other low-intensity exercise performed for 5 to 10 minutes warms your muscles, making them more flexible and less prone to injury. Your selection of stretches depends on the type of exercise you plan to do. Hold each stretch for 30 seconds and do not bounce.

Immediately after your conditioning exercise, allow your heart rate to return slowly to normal. Stretch the muscles used during exercise and prevent blood from pooling in your legs. Walking slowly, for example, will let you cool down and allow your heart and breathing to return to normal levels. After stretching, your muscles will be more flexible and less stiff. Devote a total of 5 to 10 minutes to cool down. You can use warm-up exercises for cool-down exercises.

Calories Burned in Various Activities

In planning your exercise, consult the following table that gives average calories burned for selected activities.

 
Calories Burned Per Minute    Activity 
--------------------------    ------------------------------
2 to 2.5                      Standing 
2.5 to 4                      Walking 2 miles an hour 
                              Bicycling 5 miles an hour 
4 to 5                        Walking 3 miles an hour 
                              Bicycling 6 miles an hour 
                              Badminton 
                              Housework 
5 to 6                        Walking 4 miles an hour 
                              Dancing 
                              Raking leaves 
                              Calisthenics 
                              Tennis (doubles) 
6 to 7                        Bicycling 10 miles an hour 
                              Skating 
                              Shoveling dirt 
                              Sexual activity 
7 to 8                        Walking briskly 5 miles an hour 
                              Tennis (singles) 
                              Shoveling snow 
                              Downhill skiing 
                              Water-skiing 
8 to 10                       Jogging 5 miles an hour 
                              Bicycling 12 miles an hour 
                              Basketball 
                              Mountain-climbing 
                              Ditch-digging 
10 to 11                      Jogging 6 miles an hour 
                              Cross-country skiing 
                              Squash and handball 
12                            Swimming 
------------------------------------------------------------