Study On The Dynamic Change Trend Of Physical Fitness And Its Influencing Factors Among Medical Students

Objective: Physical fitness is a set of attributes that reflect a person's ability to perform physical activities,usually including muscle strength,speed,endurance,flexibility,and body composition.Physical fitness can measure the physical condition of college students,and the development of physical fitness is of great significance for improving the physical fitness and health level of college students.As the core of the future national medical and health service,medical students' physical fitness will directly affect whether they can undertake the heavy medical work.If the medical work cannot be undertaken due to the physical condition,then the future medical and health undertakings of the country are worrying.Physical fitness is the core of physical health.From this point of view,it is of great and far-reaching significance to take the dynamic study of physical fitness as a starting point and provide reference for medical students to improve physical fitness and form good living habits.Therefore,this study mainly conducted physical fitness tests on medical students in China medical university through longitudinal studies to explore their development trends and influencing factors in physical fitness.Methods: The study was conducted from October 2016 to October 2018.5495 students from China Medical University were selected in 2016 for cross-sectional study,and 1323 freshmen were enrolled in 2016 for longitudinal study.The study was conducted in the form of physical fitness tests and questionnaires.Physical fitness test indicators for males were height,weight,vital capacity,50-m run,standing long jump,sit-and-reach,1,000-m run and pull-up.Physical fitness test indicators for females were height,weight,vital capacity,50-m run,standing long jump,sit-and-reach,800-m run and sit-up,and their BMI index.The questionnaire survey mainly included the basic information of the participants and their parents,the exercise habits,eating habits,and lifestyle of the participants.Data was entered using EpiData 3.1 software,and statistical analysis was performed using SPSS 20.0 software and SAS 9.4 software.In the cross-sectional study,the chi-square tests were used to compare the passed rate of physical fitness under different demographic characteristics and habits.Grouping based on physical fitness scores,a physical fitness score of 60 or more was passed grade,and a score less than 60 was no passed grade.Physical fitness(passed = 0,no passed = 1)was used as thedependent variable,and lifestyle-related factors were used as independent variables.Binary logistic regression analysis was performed to explore the factors that affected the overall physical fitness.In the longitudinal study,according to the physical fitness data of2016 undergraduates in their freshman,sophomore,and junior year,taking the total physical fitness scores as the dependent variable,the linear development models were used to explore the development track of medical students' physical fitness.In addition,we added time-varying covariates,and explored the effects of exercise and other factors on physical fitness.Results:(1)Cross-sectional study: A total of 5495 valid questionnaires were collected in this study,and the effective recovery rate of the questionnaire was 92%.The differences in the passed rates of physical fitness among medical students between different grades were statistically significant(P<0.001).As the grade increasing,the passed rate showed an upward trend.Parental education,breakfast frequency,and Internet addiction were related to the passed rates of physical fitness among medical students.Under different conditions of passed rate,medical students had different scores of exercise,nutrition,health responsibility,and stress management.Medical students with good physical fitness had higher scores in the four dimensions of lifestyle(P<0.05).Grade,exercise,and breakfast frequency were protective factors of male medical students' physical fitness.Grade and mother's education level were related to the physical fitness of female medical students.(2)Longitudinal study: Judging from various physical fitness indicators,the scores of sit-and-reach in males and females have increased.The decline indicators in males' physical fitness were mainly standing long jump,1,000-m run,and vital capacity.And the decline indicators in females' physical fitness was the standing long jump,but the females' physical fitness scores on the sit-up indicator have increased.There was heterogeneity among the participants in the longitudinal study of medical students' physical fitness(ICC = 0.62),and linear growth models were used for analysis.The average score of physical fitness among male medical students showed a decreasing trend,from 70.09 point to 64.46 point;the average score of physical fitness among female medical students fluctuated a little,and the larger the baseline score of female medical students' physical fitness,the smaller changes of physical fitness over time(P<0.001).We used the physical fitness scores of males and females as the dependentvariable and added time-varying covariates into the models,the results of the linear growth models showed that the main influencing factor of males' physical fitness was exercise,and exercise had a positive effect on changes in physical fitness(P<0.05).The main influencing factors of females' physical fitness were exercise and Internet addiction.Exercise had a positive effect on changes in females' physical fitness(P<0.05),and Internet addiction had a negative effect on changes in females' physical fitness(P<0.001).Conclusion: Physical fitness of medical students generally declined linearly over time,the physical fitness of male students declined more obviously,but there were significant differences in the trajectories of physical fitness among individuals.The physical fitness among female medical students did not change a lot,and the higher the baseline level of physical fitness,the lower change rate of physical fitness over time.Regardless of males and females,exercise had a positive impact on changes in physical fitness,and Internet addiction had a negative impact on females' physical fitness.Therefore,in-depth research on the changes in medical students' physical fitness and related factors of physical fitness was of great significance for scientifically improving the medical students' physical fitness and healthy life consciousness.