A、It can be done anywhere, anytime. B、It can be done at home in the evening. C、It can be done in the park at weekends. D、It can

Many people in the world walk to work or to school. They have no other form of transportation. Many others, however, travel by bus, train or car. They walk very little. Yet experts say walking is one of the best ways to stay healthy.  They call it the world’s most natural exercise which can be done anywhere and anytime. Walking is lees dangerous than running,  It strengthens muscles without stretching them too much. And it puts less pressure on bones and joints. About 50 million Americans are active in what is called "fitness" walking. They take short walks a few times each week to improve their health. Fitness walking can be done almost anywhere, anytime. No special equipment is needed. Experts advise drinking lots of liquids, especially water, before and after each walk. Also, gently stretch the muscles and joins that are mostly likely to become tense during exercise.
   Experts say the most effective way to walk is the natural way. Keep your head high and your back straight. In fitness walking, it is important to remember that your footsteps should fall almost in a straight line: Bend your arms at the elbow. Let them swing from the shoulder with each step. Walking is good for the health of your body. And a new study provides details about the link between walking and your emotional health. Robert Thayer of California State University asked a group of students to describe their feelings of energy and tension. Then he sent the students on a fast walk for ten minutes. When the students returned, they reported feeling less tired and full of energy.