Objective: To explore the effectiveness of the "National High-level Sports Reserve Talent Base" test battery on the sports positioning of young athletes by constructing an event discriminant model, and to obtain characteristic indicators for talent identification furtherly. Methods: Youth athletes (663 males and 662 females) aged 11-18 years from two municipal sports schools in Shanghai in the past five years (2015-2019) were selected, with each group of two years old. Standardized discriminant analysis was applied to explore the ability of the base test battery to correctly orient the athletes in the sports they were engaged in. Stepwise discriminant analysis further screened out the relatively important characteristic indicators in sports orientation, which were validated by the "leave-one-out" method of cross-validation. Results: The base test battery correctly classified 77.0% of the initial cases of male athletes aged 11-12, 51.2% of those aged 13-14, 60.6% of those aged 15-16, and 77.4% of those aged 17-18 by standardized discriminant analysis. The correct rate of classification after cross-validation decreased to 48.0%, 36.5%, 40.4%, and 63.2%, respectively. The correct classification rate for initial cases of female athletes was 61.7% for 11-12-year-olds, 54.0% for 13-14-year-olds, 61.1% for 15-16-year-olds, and 90.1% for 17-18-year-olds, and after cross-validation the rate decreased to 31.6%, 32.5%, 37.3%, and 71.8%, respectively. By stepwise discriminant analysis, the characteristic indicators that contributed to the correct orientation were shoulder width and calf length at age 11-12, Lower limb length B, thigh circumference, lung capacity and back strength at age 13-14, Lower limb length B, calf circumference, thigh circumference and back strength at age 15-16, height, chest circumference and back strength at age 17-18. The characteristic indicators of the female athletes were calf length and lung capacity at 11-12-year-old, weight, span, Lower limb length B, and back strength at 13-14-year-old, Lower limb length B, back strength and the sum of skinfold thickness at 15-16-year-old, height, weight, calf circumference, the sum of skinfold thickness and back strength at 17-18-year-old. Conclusion: The base test battery showed moderate to high validity for sports orientation in youth athletes, which would be influenced by age and events. Lower limb length B and back strength showed strong sports orientation effects in the mid-to-late adolescence, while calf length showed an orientation advantage in early-adolescence, which could be used as characteristic indicators for sports recommendations. |