题目内容
Nowadays more and more people are interested in aerobic(adj. 健身操) exercises. There are many such programs on TV or you can just go to a club to learn the exercises. But here is some advice for you to follow once you decide to take them up or are just about to start.
First, get your doctor's permission to start an aerobic exercise program. He or she will check your physical condition and tell you whether it's safe to start exercising.
Make sure that each time you start with a warm-up period. You should stretch(伸展)your muscles and get them ready for your workout. Warm up for at least five minutes.
Then start actual training. Jog, bike, or do exercises that get your heart rate up to the target range. Depending on your age and your physical condition, aim to raise your pulse rate to be to between 140 and 160 beats per minute. Take your pulse during exercises to make sure that your heart rate doesn't get too fast. After the 20-minute aerobic exercises, start cooling down. Do a few gentle stretches while you catch your breath. If your heart rate does not return to a resting rate (about 70) within five minutes, you're working out too hard. Finally, during the recovery period, sit down and relax. The following graph(图表)will help you to learn about the safe pulse rate in each period.
68. You should before you start an aerobic exercise program.
A. make sure that you are young enough
B. make sure that you have learned warm-up exercises
C. go to a doctor for a medical examination
D. learn a course of aerobic exercises on TV
69. What should your pulse rate be at the beginning of the cool-down period?
A. Around 70 beats. B. Around 90 beats.
C. Around 130 beats. D. Around 150 beats.
70. The warm-up period should last at least .
A. 5 minutes B. 10 minutes C. 15 minutes D. 20 minutes
CDA
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