Different exercise types have different purposes and different benefits. One type of exercise may not accomplish all goals of being physically fit: a healthy heart, strong muscles and bones, and safety from injury. As a result, it is important to do enough types of exercise to have all the physical benefits. Here is a quick check sheet. Aerobic Exercise: To have a strong and healthy heart, you need to do aerobic exercise. This means that you need to exercise yourself enough so that your heart rate, while exercising, is 65 percent to 85 percent of your maximum heart rate. If you don’t get your heart rate up within this level—you just aren’t working hard enough. Whatever you do, your heart rate needs to be 65 percent to 85 percent of your MHR for 20 to 30 minutes, at least 3 times a week. Typical types include: * Running * Walking (at least 4 to 4.5 mph) * Swimming * Biking * Elliptical Training (椭圆运动) * Yoga Strength Training: To keep your muscles and bones strong, you need to do strength training. This comes in a variety of forms. Whatever you do, however, you need to train your muscles enough so that they are really tired by the end of each session . To see real benefits, make sure you are strength training 2 to 3 times a week for about 30 to 40 minutes. Typical types of strength training include: * Weight Training * Yoga * Resistance Training * Plyometrics（肌肉增强训练） Flexibility Training: To keep your body flexible, reducing risk of injuries and pain in your joints and muscles, you need to do flexibility training. You should always aim to stretch every muscle after any exercise routine. Typical types of flexibility training include: * Stretching * Yoga * Pilates（普拉提课程） So next time you think that yoga 5 times a week will be enough, think about what it is really doing. Is it getting your heart rate up? Are you up your strength? Are you keeping your muscles flexible? 小题1:If your purpose is to _______, you can choose swimming as your exercise form. A．build a strong and healthy heart B．keep muscles and bones strong C．keep body flexible D．reduce risk of injuries and pain in joints and muscles 小题2:After reading this passage, we know that ________. A．Yoga is really better for people than running B．The more exercise you do, the better C．Flexibility training helps you build up your muscles D．The three kinds of training have links with one another 小题3:Which of the following is closest in meaning to “session” in Paragraph 3? A．meeting B．gathering C．period D．term 小题4:The paragraph following this article may discuss_______. A．how to find a good workout dealing with two or three of these goals B．how to choose an exercise type C．how to build up our strength D．how to be more flexible