2 . How exercising changed their life

4 . Teenagers’ fitness is now a major concern，and physical exercise is very important. It reduces stress and improves fitness. Exercise makes your body strong，and helps you to keep the right body weight. Sports scientist Dr. Helen Lopez offers the following advice to teenagers：“First，you need to find out your present level of fitness. Then you can design a programme that will help you become healthier.”

Dr. Lopez suggests that there are three levels of fitness that need a change of lifestyle.“Overweight”means that the person gets very little exercise and often has a serious weight problem. “Inactive” means that the person does not join in many physical activities，but is not seriously overweight.“Active”refers to people who take part in sports and other physical activities，but do not have a high fitness level.

According to Dr. Lopez，overweight teenagers should work out to keep healthy.“Ride a bike，play volleyball or basketball for a while，and go for a twenty­minute walk each day. All these will help to burn calories.”Inactive teenagers should do similar activities, but add some bending and stretching exercises, such as push­ups and sit­ups, starting with twenty of each a day.“Inactive people can take a little more exercise than overweight people because their bodies are stronger，”Dr. Lopez said. The same rule applies to active teenagers.

Dr. Lopez suggests one hour a week or more on running and other forms of intensive exercise，together with fifteen minutes a day spent on stretching and bending activities.“These are really important in order to prevent injuries,” Dr. Lopez said. Some weight­training and other body­strengthening exercises could also be planned in the programme in order to increase the person’s strength.

5 . Fitness Magazine recently ran an article titled “Five Reasons to Thank Your Workout Partner.” One reason was: “You’ll actually show up if you know someone is waiting for you at the gym, ” while another read: “    1    ”   With a workout partner, you will increase your training effort as there is a subtle (微妙) competition.

So, how do you find a workout partner?

First of all, decide what you want from that person.     2     Or do you just want to be physically fit, able to move with strength and flexibility? Think about the exercises you would like to do with your workout partner.

You might think about posting what you are looking for on social media, but it probably won’t result in a useful response.     3     If you plan on working out in a gym, that person must belong to the same gym.

My partner posted her request on the notice board of a local park. Her notice included what kind of training she wanted to do, how many days a week and how many hours she wanted to spend on each session, and her age. It also listed her favorite sports and activities, and provided her phone number.     4    

You and your partner will probably have different skills.     5     Over time, both of you will benefit—your partner will be able to lift more weights and you will become more physically fit. The core (核心) of your relationship is that you will always be there to help each other.

7 . All over the world people enjoy sports. Sports help to keep people healthy and happy, and to live longer.     1    . They buy tickets or turn on their TVs to watch the games. Often they get very excited when their player or team wins.

    2     Football, for example, has spread around the world. Swimming is popular in all countries near the sea or in those with many rivers. What fun it is to jump into a pool or lake, whether in China, Egypt or Italy!     3    . Think how many lovers to skate or ski in Japan, Norway or Canada.

Some sports or games go back thousands of years, like running or jumping. Chinese wushu, for example, has a very long history. But basketball and volleyball are rather new. Neither one is a hundred years old yet.    4    . Water-skiing is one of the newest in the family of sports.

People from different countries may not be able to understand each other, but after a game together they often become good friends.     5    . One learns to fight hard but fight fair, to win without pride and to lose with grace.(胜不骄，败不馁)

8 . One major reason Americans don’t get enough exercise is that they feel they don’t have enough time. It can be difficult to squeeze in the 75 minutes of aerobic (有氧的) exercise per week that federal guidelines recommend.    1    .

In a new analysis of 14 studies, researchers tracked deaths among more than 232,000 people from the U.S., Denmark, the U.K. and China over at least five years, and compared the findings with people’s self-reports about how much they ran. People who said they ran any amount were less likely to die than those who didn’t run at all.    2     This was true even for those who didn’t log a great deal of time. The analysis divided people into groups, with 50 minutes or less per week representing the group that ran the least―but still ran. ‘‘Regardless of how much you run, you can expect such benefits,” says Zeljko Pedisic, one of the authors of the new analysis published in the British Journal of Sports Medicine.

The analysis is the latest to illustrate the benefits of running on the human body. It’s what we evolved (进化) to do.     3     But as leisure-time exercise, running keeps us healthy. “One of the best ways to avoid having to see a doctor,” Zeljko says, “is to stay physically active.”

    4     Running is good at guarding against cancer partly because it uses up blood sugar, starving the cancer cells that rely on it for fuel. And it protects you in other ways not necessarily measured in the latest research: by decreasing inflammation (炎症), for example, which is at the root of many diseases, and stimulating the production of a protein that improves brain health.

    5     Neither were how often people ran and the pace they kept. As long as you’re running, more isn’t always better, especially given that the risk of injury increases with repetition.

9 . Older women who walk a little over three kilometers each day might live longer than less active women of the same age, a new study suggests.

Many Americans hoping to stay healthy set a daily goal of 10, 000 steps, or about eight kilometers. They often have this goal because they are wearing electronic devices which set that target, note researchers in the United States. Their findings appeared recently in the publication JAMA Internal Medicine.

But it is not clear how much intensity(强度)or speed matter when counting the health benefits of every step, the researchers write. They add that 10,000 steps per day might not be the right goal for everyone.

For the study, researchers observed 17,000 women, all in their early 70s. They asked the women to wear accelerometers for at least four days. Accelerometers are small devices that measure the number of steps and the intensity of movement. The researchers followed up with the women much later, around 4. 3 years later, on average. Since the beginning of the study, 504 women had died. Compared to women who took no more than 2, 718 steps daily, the women who took at least 4,363 steps per day were 41 percent less likely to die.

“Even a modest amount of steps is associated with lower death rates, "said I-Min Lee, the lead writer of a report on the study. "The rate of stepping did not matter in these older women: it was the number of steps that mattered.

The study had a few limitations. For example, the researchers only measured women’s movements once, at the start of the study period. It is possible that the women’s behaviors changed over time. Still, the results are "good news for older adults who may have difficulty walking at faster paces, "said Keith Diaz, a researcher at Columbia University. He was not involved in the study.

“Any walking is better than nothing, " Diaz said by email. "With even small amounts of walking, your risk of death will be sharply reduced "For those who have difficulty walking, other research shows that any form of aerobic activity provides health benefits," he added. "Swimming, bicycling or any form of activity that is continuous in nature will provide health benefits.

10 . A study has found that a lifetime of regular exercise and activity can slow down the aging process (衰老过程). Researchers say that getting older should not necessarily mean becoming more weak or sick. Their research shows that a devotion to a life of movement and exercise may help us live not only longer, but also healthier.

For their study, the researchers looked at two groups. The first group was made up of 125 non-professional cyclists between the ages of 55 to 79. This group included 84 healthy men and 41 healthy women. We will call this group the “cyclists”.

Researchers then found 130 people to make up a second group. Within this group, 75 people were aged from 57 to 80. The other 55 were between the ages of 20 and 36. The people in this group were also healthy, but they did not exercise regularly. We will call this group the “non-exercisers”. Smokers, heavy drinkers of alcohol and people with other health issues were not included in the study.

Then, researchers gave both groups a series of tests. They tested their muscle mass (肌肉质量), muscular strength, percentage of body fat and the strength of their immune (免疫的) systems. Then the researchers compared the results of the two groups.

Results showed that the cyclists did not experience body changes usually regarded as a normal aging process. For example, they did not lose muscle mass or muscular strength. Also, their body fat did not increase with age.

The researchers also found something they had not expected. The study showed that the immune systems of the cyclists did not age either.

The researchers advise us all to find an exercise that we like in our lives.