Comparison of physical activity, sedentary time, and physical fitness among Chinese children and adolescents in Qinghai between 2019 and 2023.

This study aimed to assess the differences in physical activity and physical fitness in 2019 and 2023 among children and adolescents in Qinghai Province. Data were collected from the Chinese National Survey on Student Constitution and Health (CNSSCH) in 2019 and 2023. The study ultimately included 13,296 participants (5,039 in 2019 and 8,257 in 2023) aged 6-22, including primary, middle, and high school students in Qinghai Province, China. Physical fitness assessments included height, weight, vital capacity, sit-and-reach distance, pull-ups, timed sit-ups, standing long jump, 50-meter dash, 800-meter run, 1000-meter run, 50 m × 8 shuttles run, and timed rope-skipping. Independent samples T-tests and multiple linear regression analyses were employed to explore differences and associations in moderate-to-vigorous physical activity (MVPA), sedentary time (SED), and physical fitness in this population in 2019 and 2023. Compared to 2019, children and adolescents measured in 2023 showed a significant increase in MVPA and a significant decrease in SED. Vital capacity improved significantly across all academic stages, with primary school girls showing improved performance in the 50 × 8 shuttles run. Secondary school students significantly declined in their performance in 800 m and 1000 m runs. Standing long jump performance improved for middle and high school students, while pull-ups declined for high school boys. Timed sit-ups declined for middle school girls, with no significant changes at primary and high school. Flexibility improved for high school boys and both middle and high school girls but decreased for primary school boys and girls, as well as for middle school boys. Timed rope-skipping was measured only in primary school students, and it improved significantly. Speed performance, measured by the 50 m dash, improved in primary school students but declined in middle and high school students. Regression analysis revealed that MVPA was positively associated with vital capacity, 800 m running, standing long jump, pull-ups, and timed sit-ups, while negatively associated with 1000 m running, timed rope-skipping, and 50 m dash. SED was positively associated with 800 m and 1000 m running performance and timed sit-ups. Our study highlights distinct trends in physical fitness across school stages, and sex associations of MVPA and SED with fitness outcomes underscore the need for tailored, region-specific health strategies in high-altitude, underdeveloped areas.