Phase-specific changes in anthropometric and physical fitness outcomes among Chinese upper-secondary students before, during, and after the COVID-19 pandemic: the moderating role of educational track.

Statistically robust phase-related variations and phase-by-school-type interactions were observed across all physical fitness domains among Chinese upper secondary students before, during, and after the COVID-19 pandemic.

• Study used large-scale school-based fitness surveillance data collected across three pandemic phases: before, during, and after COVID-19.
• Students were aged 15-18 years and stratified by educational track: general academic versus vocational education.
• Outcomes analyzed spanned explosive power, endurance, flexibility, and anthropometric measures.
• Phase effects and phase-by-school-type interactions were assessed across all fitness domains.
• Responses were described as 'highly domain-specific' rather than uniform across fitness categories.

Anthropometric indicators followed overall upward trajectories consistent with long-term secular patterns, with vocational education students exhibiting greater temporal sensitivity to pandemic-related disruption.

• Anthropometric measures showed an overall upward trend across the three pandemic phases.
• This upward trajectory was characterized as consistent with long-term secular patterns.
• Vocational education students showed greater temporal sensitivity to pandemic-related disruption compared to general academic track students.
• The phase-by-school-type interaction was observed for anthropometric outcomes.

Explosive power showed relatively small phase effects but large and persistent between-school differences across the pandemic phases.

• Phase effects on explosive power were described as 'relatively small' compared to other fitness domains.
• Between-school differences in explosive power were characterized as 'large and persistent.'
• This pattern suggests that educational track differences in explosive power were maintained regardless of pandemic phase.
• Explosive power was among the outcomes analyzed using school-based fitness surveillance data.

Endurance performance displayed pronounced phase-dependent changes including delayed differentiation between educational tracks.

• Endurance showed 'pronounced phase-dependent changes' across the three study periods.
• A pattern of 'delayed differentiation in endurance performance' was observed between school types.
• This suggests that differences between general academic and vocational students in endurance emerged or widened at a later phase rather than immediately.
• Endurance was one of the fitness domains most affected by pandemic-phase variation.

Flexibility disparities between educational tracks temporarily narrowed during the pandemic phase.

• Flexibility displayed 'pronounced phase-dependent changes' similar to endurance.
• A 'temporary narrowing of between-school disparities in flexibility during the pandemic' was observed.
• This narrowing suggests that the pandemic disruption differentially affected flexibility across educational tracks in a way that reduced inequality temporarily.
• The narrowing was characterized as temporary, implying disparities may have re-emerged in the post-pandemic phase.

The educational track moderates vulnerability and recovery across fitness domains during large-scale societal disruptions such as the COVID-19 pandemic.

• Vocational education students showed differential responses compared to general academic track students across multiple fitness domains.
• The moderating role of educational track was observed across anthropometric indicators, explosive power, endurance, and flexibility.
• The findings indicate that pandemic disruptions reshape 'developmental patterns and inequality dynamics rather than uniformly depressing fitness levels.'
• Authors concluded there is a need for fitness monitoring and intervention strategies 'sensitive to both domain-specific characteristics and the educational context.'