One possible version:

Health is very important to us teenagers. Either study or work is based on strong body. Doing sports 

every day helps us keep healthy and energetic. If we don't take any exercise, we may feel tired and get sick

easily. Just as the slogan says, "Exercise one hour a day, keep illness away!"

There are many kinds of sports we can do, such as running, swimming and ball games. 

Now we students have to do too much homework after school. I hope teachers will leave us less 

homework so that we can have more time to take part in sports. I also hope our school can organize more 

sports activities for us.

题目分析：

这是一篇给材料作文，介绍青少年锻炼身体的好处和锻炼身体的方式。结合所给材料，。在写作时，本文的主语可以用第二人称，时态一般应该用一般现在时。句子结构主要为动宾结构，注意一些常见句式的应用，比如：If we don't......，There are……及I hope……等句式的应用。写作中注意运用短语，注意多种句式交替运用。写作中注意叙述顺序，符合逻辑关系， 应该尽量包括文中提示的内容，可稍加拓展

【亮点说明】本文结构紧凑，语言简练。开头说明青少年体育锻炼的好处，然后，分别叙述体育锻炼的方式。最后，希望学校多组织体育活动。此处用了keep illness away ，Just as，take part in，等这些词组的运用也让文章增色不少。