We all need to exercise. Doctors say it is good for us. It makes your heart and body strong. It also gives you more energy. And you will feel better about yourself. It's best to exercise twice a week. Twenty minutes each time is enough(足够).

      There are many ways to exercise. You can walk, run, play sports, or swim. Many people go to special (特殊) places to exercise.

      They are called “fitness centers”. These places have a lot of equipments (设备) . Some people buy equipment for their homes. But it is very expensive.

      Exercising can be fun. Friends can exercise together at a fitness center. Or, they can play sports together. How do you exercise?