Secular trends in physical fitness between 2004 and 2022 in Belgian children aged 10–12 years: findings from a long-term school-based surveillance program
A long-term surveillance study of over 70,000 Belgian children aged 10–12 revealed significant secular declines between 2004 and 2022 in most physical fitness parameters, including cardiorespiratory endurance, speed, flexibility, and lower-limb strength, underscoring the urgent need for targeted public health interventions.