Mediating role of physical health belief in the relationship between adolescents' BMI and exercise behavior

Objective To explore the intermediary role of physical health belief in the relationship between BMI and exercise behavior,in order to provide references for the promotion of physical health of teenagers.Methods A total of 1 678 middle and high school students in Beijing,Jinan and Guiyang were selected as the research subjects to test their height and weight,and the Physical Health Belief Scale and the Physical Exercise Scale were carried out to collect the scores.Results In the overweight and obese group,the score of perceived exercise benefits (14.07±0.25,14.24±0.54),attitude toward physical fitness evaluation (14.26±0.63,13.72±0.41),physique and disease susceptibility (15.12±0.72,14.12±0.61),seriousness of perceived disease and bodily weakness (14.30± 0.55,12.88±0.27),attention to the results of evaluation(14.12±0.56,13.76±0.23),exercise (61.13± 0.53,57.74±0.37) were lower than those of the normal group,the difference was statistically significant(P<0.05).BMI was negatively related to perceived exercise benefits,attitude toward physical fitness evaluation,physique and disease susceptibility,seriousness of perceived disease and bodily weakness,attention to the results of evaluation(r =-0.195,-0.174,-0.163,-0.122,-0.129,-0.203,P<0.01),and negatively correlated to exercies(r=-0.203,P<0.01).Moreover,perceived exercise benefits,attitude toward physical fitness evaluation,physique and disease susceptibility,seriousness of perceived disease and bodily weakness,attention to the results of evaluation were positively related to exercise(r=0.447,0.619,0.407,0.589,0.308,P<0.01).The influence of the health belief on the exercise behavior was greater,the relationship between the BMI and the exercise behavior was mediated by the physical health belief.Conclusion With the increase of BMI index,the scores of health belief and exercise behavior decreased;physical health belief made greater effect on exercise behavior than BMI,and physical health belief played an intermediary role in the relationshrip between BMI and exercise behavior.It can improve the health belief of teenagers to promote their physical fitness and enhance physical health.