Have you tried to run or walk for exercise and then given up? If you answered yes, you should try a new kind of exercise: aquatic (水中的) exercise. Aquatic exercise is like exercise on land, but you do it in a swimming pool. More and more people are trying aquatic exercise.

Aquatic exercise feels easier than exercising on land. Why? You weigh about 90% less in the pool. It is better for your knees than running or walking. Water is about 1,000 times thicker and heavier than air. To move through the water, your body has to work four times as hard. So you can burn (燃烧) more calories (卡路里).

In fact, most people say they feel more relaxed in the water. They stop thinking about the worrying things. The cool, quiet environment makes them feel good.

But what if you are afraid of the water? No problem! There is nothing to worry about. Aquatic exercise is safe and easy to learn. It doesn’t need any special skills. You don’t even need to know how to swim. Aquatic exercise is for everyone.

Sports can help you keep fit and close to nature. However, whether you are on the mountains, in the waves, or on the grassland, you should realize that the sport you choose might have great influence on the environment.

Some sports are resource--hungry. Golf, as you may know, eats up not only large areas of countryside, but also lots of water. Besides, huge amounts of energy are used to keep its courses(球场) in good condition. This causes major environmental changes. For example, in the dry places of Portugal and Spain, golf is often held responsible for(为……承担责任) serious water shortage(短缺) in some local areas.

There are many environment-friendly sports. Power walking is one of them that you could take up today. You don’t need any special equipment except a good pair of shoes, and you don’t have to worry about resources and your purse. Simple and free, power walking can also help you stay healthy. If you walk regularly, it will be good for your heart. Experts say that 20 minutes of power walking daily can make you feel less anxious, sleep well and keep thin.

Whatever sport you take up, you make it greater by using environment-friendly equipment and buying products made from recycled materials. But the final goal should be “green gyms”. They are better replacements(替代) for traditional health clubs and modern sports centers. Members of green gyms play sports outdoors, in the countryside or other open spaces. There is no special requirement for you to start your membership(会员身份). And best of all, it’s free.