Exercise can sometimes be divided into three categories. First, you have stretching, a form of exercise that seeks to enhance flexibility and lengthen the muscles. Then, you have strength training, which is exercise intended to strengthen the muscles and build new muscle tissue. Finally, you have cardiovascular exercise, which seeks to strengthen the heart and cardiovascular function.
Many people feel that a balanced exercise plan includes some of all three types of exercise. Others really prefer to do just cardio or just strength. If you want to learn more about these ideas, and about exercise in general, we recommend checking out this blog.