Classroom Break, Cognition, and Fitness in Elementary School Children

The goal of this randomized controlled trial is to learn about the effect of a 12-week school-based intervention combining mindfulness with high-intensity interval training (MF-HIIT), MF-only intervention, and HIIT-only intervention in relative to sedentary activities on executive function (EF) in 8-12 years old children. The main question it aims to answer is whether a 12-week school-based MF-HIIT intervention has larger beneficial effect on EF performance than that following a 12-week school-based MF-only and HIIT-only in relative to the sedentary activities.

Multiple cohorts of participants will be recruited to participate this one-semester study, including the pretest, intervention, and posttest phases.

During the pretest phase, participants an their parents will complete the following

• Kaufman Brief Intelligence Test (KBIT) to assess intelligence quotient
• Fitnessgram test to assess aerobic capacity, muscle endurance, flexibility, and body mass index
• Child and Adolescent Mindfulness Measure (CAMM) questionnaire to assess dispositional mindfulness
• Computerized tasks to assess EF
• Parent-reported demographic and health information

Following the pretest phase, participants will receive the 12-week classroom-based intervention, with the classroom as the intervention unit.

Following the intervention and during the posttest phase, participants will complete the fitness, measures, EF measures, and dispositional mindfulness measure again.

Researcher will compare the EFn outcome measures following the MF-HIIT, MF-only, and HIIT-only interventions with the sedentary activity intervention to see if MF and HIIT has beneficial effects on children's EF.

Further, researcher will compare the EF measures following the MF-HIIT compared with MF-only and HIIT-only interventions to see if combining MF with HIIT has greater beneficial effects on children's EF than MF and HIIT alone.