BMI and physical fitness in Chinese adult students: a large school-based analysis.

OBJECTIVE The purpose of this study was to evaluate the relationship between body mass index (BMI) and a physical fitness index (PFI) in Chinese college freshmen based on 50-meter run. DESIGN AND METHODS Cross-sectional survey from 2007 to 2009. The records of 3825 men (age 18-31) and 4062 women (age 18-30) studying in Anhui medical university were examined. Height and weight were measured by trained teachers, and 50-meter run test was performed as PFI. RESULT More men than women were overweight or obese (5.8% vs 2.1%), but more women than men were underweight (21.1% vs 16.9%). In all five BMI groups, men performed significantly better than women (p < 0.05). In both genders, decreasing performance was observed from normal weight or underweight to overweight and thinness (p for trend < 0.05). The relationship between BMI and PFI of men is nonlinear and varies with age, and the curvature of this parabola increases continuously. The relationship between BMI and PFI of women is not clear. CONCLUSION The relationship between PFI and BMI of adult men conforms to the quadratic model, and the influence of PFI by BMI is more serious in middle-age male than youth male.