Secular trends in physical fitness and cardiovascular risks among Chinese college students: an analysis of five successive national surveys between 2000 and 2019.

Background: With increasing concerns about early-onset cardiovascular diseases, it is essential to understand the distribution of cardiovascular health among young adults. This study aimed to characterize trends in physical fitness and the prevalence of overweight/obesity (OWOB), elevated blood pressure (EBP), and their comorbidity among Chinese college students from 2000 to 2019 and to analyze the changes in their associations and subgroup differences. Methods: Data were extracted from five cycles of the Chinese National Survey on Students' Constitution and Health (2000-2019), including 241,710 college students aged 19-22. Physical fitness indicator (PFI) was computed using standardized z-scores of forced vital capacity, sit-and-reach, 50-m dash, standing long jump, muscle strength, and endurance running. OWOB was defined as a body mass index ≥25 kg/m Findings: The median of college students' PFI deteriorated continuously from -0.16 in 2000 to -1.99 in 2019, with boys experiencing a faster decline than girls. The prevalence of OWOB, EBP, and comorbidity increased significantly from 3.7%, 2.2%, and 0.3% in 2000 to 14.0%, 5.2%, and 1.8% in 2019, respectively, with boys exhibiting higher prevalence than girls. Decreasing PFI levels were significantly associated with the increasing prevalence of OWOB, EBP, and comorbidity, and such associations were strongest in 2019. L-shaped curves were observed for the relationships between PFI and the prevalence of OWOB, EBP, and comorbidity, with stronger associations in boys. Provincial population attributable fraction showed that when improving the PFI levels from low to middle-low or above, college students in Guizhou, Sichuan, and Yunnan provinces exhibited the most reductions in OWOB, EBP, and comorbidity. Interpretation: Physical fitness among Chinese college students has significantly declined over the past two decades, accompanied by marked increases in the burden of cardiovascular risks. There is an urgent need to increase the focus on college students' health and establish a college-based physical examination system to assess their long-term cardiovascular function. Funding: The present study was funded by National Key R&D Program of China (Grant No. 2024YFC2707901 to Yi Song), National Natural Science Foundation of China (Grant No. 82273654 to Yi Song), and Beijing Office for Education Sciences Planning (Grant No. BBAA22027 to Yi Song).