2 . Physical education, or PE, isn’t required for all high school students. In some schools, it isn’t offered for some different reasons. But should high school students have physical education? The answer is certainly “yes”.

Today many people don’t do sports. But as is known to all, doing sports is very important for an adult. Teaching teens the importance of a healthy lifestyle and making fitness plans now can help teens put exercise in the first place as an adult.

High school isn’t that easy. Many students are under a lot of stress. Stress can be harmful to a student’s study and life. Doing sports can help them deal with stress better, helping them live a happier life at school.

The American Heart Association says that 10 million kids and teens suffer from obesity (肥胖症). Teens should get 60 minutes of physical activity per day to control their weight and to help their bones get stronger. The increase in activities that don’t get teens to move around, such as video games and computer activities, means many teens don’t get their required exercise. PE classes act as a public health measure to encourage physical activities and help teens have healthy weights.

Not doing sports increases teens’ risk of developing many diseases. An active lifestyle offers a good way of protection from these health problems. As much as 75 percent of health-care spending goes toward treating medical conditions that can be hindered by lifestyle changes,according to the American College of Sports Medicine.

According to the President’s Council on Fitness,Sports and Nutrition (PCFSN), students who performed five hours of physical activity each week improved their academic (学业的) performance. Students from programs with no physical activity, who used the extra time for classroom study, did not perform better on tests than those who gave up some study time in support of physical education.

3 . Years ago, I could not stick to exercising until I bought a CD called I Enjoy Exercise. I listened to it every day. I bought the CD because I wanted to run in a race and hopefully win!

I had assured my 10-year-old son Todd that I would run in a race with him. Unfortunately, however, when that race came, his left leg was hurt in a car accident. Without him running with me, although I took part in that race, I didn’t do quite well in it.

While Todd couldn’t run together with me because of his injury (受伤), he never forgot the promise I made for him. He was always asking me whether I would keep my promise when he recovered in the future. So I decided I was going to train and go all out to win the next race. What I needed was motivation (动力). It happened that one of my friends mentioned the CD which he liked very much, saying that he got a lot from the music in it when feeling down. So I bought it and listened to it while exercising every day.

What happened to my thinking was amazing as I listened to it daily. I started to think about the repeated words on the CD — “I enjoy exercise”. Instead of dreading exercise, I was thinking, “I enjoy exercise.”

I found out how important words are that we play in our minds every day. I went from a person who seldom exercised to someone who started to exercise daily. Just think how our lives will improve if we reflect on the uplifting words of the famous works. I have found the positive messages have greatly inspired me and then changed my life.

How did I do in that race, you might be thinking? I actually became the champion in my age group.

4 . Why do we play sports? You might say “to get exercise” and you’d be right. To have fun? That’s true, too. But there’s more.    1    According to the Women’s Sports Foundation, girls who play sports get a lot more than just fitness.

Girls who play sports do better in school. You might think that playing sports will take up much of your study time.     2    Exercise improves learning, memory, and concentration, which can give active girls an advantage in the classroom.

Girls who play sports learn teamwork and goal setting skills. Sports teach us valuable life skills. When you work with coaches, trainers, and teammates to win games and achieve goals, you’re learning how to be successful.     3    Sports are good for a girl’s health. In addition to being fit and keeping a healthy weight, girls who exercise are less likely to get osteoporosis (骨质疏松症) later in life.

Playing sports improves self-confidence.    4    Why? It builds confidence when you know you can practice, improve, and achieve your goals. Sports are also a feel-good activity because they help girls keep in good shape, keep a healthy weight, and make new friends.

    5    Playing sports can reduce stress and help you feel a little happier. How? The brain chemicals released during the exercise improve a person’ mood. Friends are another mood-lifter. And being on a team creates connections between friends. It’s good to know your teammates will support you—both on and off the field!

5 . Running can be a polarizing (两极分化的) subject. Most people fall into one of two camps: those who love running every morning, and those who would sooner do anything to avoid it. For most of my life, I was planted in the second camp.

I always hated running. I remembered entering a neighborhood 5K race with my dad at age 12; I also remembered that I came in last in the race, followed by only the police car driving patiently behind me. Three years later, I didn’t make the junior volleyball team because I couldn’t run a mile in under 10 minutes. Every time I ran, I felt as though failure — in some form or other — was the only possible result.

The summer after my freshman year, though, I took a job at a summer camp in Connecticut, where I got paid to be a kid again. I spent my days keeping an eye on different camp activities. When it came to exercise, running was my only choice. So, I made a promise myself: Every day, I would run for a while. By most runners’ standards, it wasn’t far; I guessed it was only about a mile. But I decided to do it every day, no matter how long it took. The exercise lasted for 61 days — the entire time I spent at camp that summer.

I started to feel better about myself. But to my great surprise, I learned to love running, too. I went from fearing the sport to loving it. I’ve finished seven marathons (马拉松赛跑) and more shorter races than I can remember, and now I am a running coach. These were the secrets I discovered to changing my way of looking at life.

6 . Are you preparing for a big test? If so, you may want to go playing some basketball in between hitting the books. Doctors are starting to find more and more information that suggests a connection between exercise and brain development. Judy Cameron, a scientist at Oregon Health and Science University, studies brain development. According to her research,   it seems that exercise can make blood vessels (血管),   including those in the brain, stronger and more fully developed. Dr Cameron is sure that this allows people who exercise to think better. As she says, “while we already know that exercise is good for the heart, exercise can actually cause physical changes in the   brain.”

The effects of exercise on brain development can even be seen in babies. Babies who do activities that require a lot of movement and physical activity show greater brain development than babies who are less physically active. Even a little movement can show big results. Margaret Barnes, a scientist, also believes in the importance of exercise. She thinks that many learning disabilities that children have in primary school or high school can result from a lack of movement as babies. “Babies need movement that encourages and excites their five senses. They need to set up a connection between motion and memory. In this way, as they get older, children will begin to connect physical activity with higher learning，” says Margaret.

Older people can develop their brains as well. Cornell University studied a group of seniors who have a short­term memory increase of up to 40 percent after exercising just three hours a week. The exercise does not have to be very difficult, but it does have to increase the heart rate. Also, just like the motion for babies   exercise for older people should not be too simple. Learning some new skills or actions, such as with yoga or tai­chi helps to open up memory paths in the brain that may not have been used for a long time. For most people, any type of physical activity that increases the heart rate is helpful. The main aim is to increase the brain’s flow of blood. And your brain can benefit from as little as two to three hours of exercise a week.

7 . All over the world people enjoy sports. Sports help to keep people healthy,happy and help them to live longer.

Sports change with the season.People play different games in summer and winter.

Games and sports often grow out of people’s work and everyday activities.The Arabs use horses or camels in much of their everyday lives;they use them in their sports,too.

Some sports are so interesting that people everywhere go in for them. Football, for example, has spread around the world. Swimming is popular in all countries near the sea or in those with many rivers.

Some sports or games go back to thousands of years ago, like running or jumping. Chinese boxing, for example, has a very long history. But basketball and volleyball are quite new. Neither one is a hundred years old yet. People are inventing new sports or games all the time.

People from different countries may not be able to understand each other,but after a game they often become good friends. Sports help to train a person’s character (性格). One learns to fight hard but fight fair,to win without pride and to lose with grace (体面).

8 . A study published in the journal Frontiers in Psychology took a closer look at music in sports, specifically how listening to music could affect one’s overall performance.

Researchers asked 150 volunteers to throw a ball into a basket. For the first stage of the study, participants threw the ball from a fixed point. They threw the ball while listening to music of their choice, while not listening to music, or while listening to music that the researchers selected. For the second stage they were able to choose where to stand when throwing the ball and performed the same activity with the various music choices.

The study found that listening to music, whether it was music of the volunteer’s choice or a song chosen for them, did not make the participants more or less likely to get the ball in the basket. It had no effect. What it did do was increase self-esteem and make the study participants more likely to take risks, especially for males who were allowed to choose their own music.

The results suggest that music may pump you up. And it may even help you work out harder and longer than you would without it. But no matter what song you listen to, it’s not going to help you get that ball into the basket.

Another study took a detailed look at how music pace might affect exercise. Researchers found that listening to high-pace music makes people feel like they’re working out less while also benefiting their bodies more.

Listening to high-pace music while exercising resulted in the highest heart rate compared with not listening to music. This means that the exercise seemed like less effort, but it was more beneficial in terms of enhancing physical fitness.

The study found that the beneficial effects of high-pace music were greatest for people who were walking or running and were felt the least for those who were doing high-intensity exercises such as weightlifting.

10 . 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.