The association between a body shape index and cardiorespiratory fitness among adolescents in rural China: a sex-specific cross-sectional study
Chaogong Zeng, Chengjun Chai, Jiali Xu, Mian Sha, Jian Xin · Frontiers in Nutrition · 2026
Background: Cardiorespiratory fitness (CRF) among Chinese adolescents has been declining year by year, with the decline being particularly pronounced in rural areas. As a novel indicator of body composition, the a body shape index (ABSI) has rarely been examined in previous studies regarding its association with CRF among adolescents in rural areas. This study
Aims: to guide the improvement and enhancement of CRF among adolescents in rural China.
Methods: Using a stratified random cluster sampling
Method: , we conducted a cross-sectional assessment of height, weight, waist circumference, and 20-m shuttle run test (20-m SRT) performance among 18,948 adolescents aged 6–17 years in rural areas of China. We analyzed the association between ABSI and 20-meters SRT using
methods such as one-way analysis of variance (ANOVA) and linear regression analysis.
Results: Among adolescents aged 6–17 years in rural China, the ABSI was (0.069 ± 0.013) and the 20-m SRT was (29.69 ± 17.16) laps. Overall, there were statistically significant differences in the interquartile ranges of the 20-m SRT across the 6–8, 9–11, 12–14, and 15–17 age groups ( F = 33.841, 14.916, 13.858, 7.715; P < 0.001). Curvilinear regression analysis showed an inverted U -shaped relationship between ABSI and 20-m SRT. Overall, in the 6–8 years, 9–11 years, 12–14 years, and 15–17 years age groups, the 20-m SRT was highest when the ABSI was 0.056, 0.070, 0.094, and 0.054, respectively, reaching 18.673, 26.226, 38.328, and 40.499 laps, respectively.
Conclusions: There is an inverted U -shaped relationship between ABSI and 20-meter SRT among adolescents in rural China. Maintaining a reasonable ABSI may on CRF.