体育课的密度和运动量是同增强学生体质、掌握体育技能密切相关的。体育课的密度是指在一节课里,各项活动的合理时间和课的总时间比例。通常说的密度是在一节课中,学生实际练习时间与课的总时间的比例,实际上就是练习密度。如一节课45分钟,学生实际练习20分钟,其密度为(20)/(45)=44.4%。测定密度的方法:选择班级里发育中等水平的学生,将他从上课开始到下课为止的实际练习时间,按开始部分、基本部分、结束部分分别记录下来。如果开始部分为12分钟,实际练习时间为6分 The density and exercise of physical education are closely related to the enhancement of students' physical fitness and the mastery of sports skills. The density of PE lessons refers to the proportion of the reasonable time of each activity and the total time of the lesson in a lesson. The density is usually said in a class, the actual practice time and the proportion of class time, in fact, practice density. For 45 minutes of a class, students actually practice for 20 minutes and have a density of (20) / (45) = 44.4%. Method of determining density: Select middle class students in the class, the actual practice time from the beginning of the class to the end of get out of class, according to the beginning part, the basic part, the end of the part were recorded separately. If the starting part is 12 minutes, the actual practice time is 6 points