[Analysis on the relations between levels of change and the mental decisive factors on the physical exercise behavior among middle school students].

Objective: To study the situation of sports and its influencing factors among students in order to improve health related education and promotion programs.

Methods: A multistage random sampling method was used on 3 600 students from three cities to understand their physical exercise behavior. Both t and χ(2) test were used to measure the scale of psychology and to describe the time spent on exercise. Single variance factor was used to measure the levels of change on behavior of physical activities, psychological and physical exercise behaviors.

Results: The weekly exercise time for students was 2.66 ± 1.801 days, with 81.4% of the students less than four days. Data showed that 37.3%, 23.6%, 20.5% of the high school students were in pre-contemplation stage, in contemplation stage, or in preparation stage respectively, with only 18.6 percent of the high school students in the action phase and maintaining phase. Students in the stages of change increase the amount of physical exercises. Scores with statistically significant differences were seen in the following areas: between five stages of behavior change on strategies (F = 77.442, P < 0.001), forward effects on the balance of decision-making (F = 29.498, P < 0.001), having negative effects (F = 14.784, P < 0.001)and self-efficacy (F = 135.544, P < 0.001). Changing strategy on the intention stage of front maintenance phase, positive effects on decision-making balance and self-efficacy scores were increasing along with the increasing stages of changing. The effect of balancing the negative effects increased when the change of phase decreased.

Conclusion: Students were in lack of physical exercise per week. The differences related to the behavior on physical exercise did exist but most of the high school students were in the primary stage. Psychological factors played important role in the different stages of changing, suggesting that high school students should receive different health education and psychological intervention measures to enhance the effectiveness of physical exercise.