Intervention With Alternative Sports for Physical and Mental Improvement in Primary School Children

Effectiveness of an Intervention Programme Using Alternative Sports for the Recovery of Motor Learning and the Improvement of Physical and Mental Health in Primary School Students.

The objective of this clinical trial is to determine whether a school-based intervention involving alternative sports can improve physical fitness, motor skills, and psychological well-being in elementary school students. The main question to be answered is:

Can participating in a physical intervention involving alternative sports help children improve their strength, speed, endurance, motor skills, and enjoyment of physical activity? For 8 weeks, during physical education classes, researchers will compare an intervention with alternative sports (korfball, flag football, kin-ball, and ultimate frisbee) with the usual classes that students receive according to their study program, to see if alternative sports improve physical and psychological aspects.

Participants must:

• Perform physical and motor tests to determine their initial physical condition
• Complete a questionnaire to determine their level of enjoyment during physical activity.
• Actively participate in an 8-week intervention during physical education classes.
• Monitor their level of physical activity during classes using a device (accelerometer).
• Authorize the use of their first semester grades.
• At the end of the intervention, physical and motor tests will be performed again to assess progress and physical changes.

For eight weeks, researchers will conduct a study in physical education classes to compare two types of teaching: one based on alternative sports (such as korfball, flag football, kin-ball, and ultimate frisbee) and another with traditional school program classes to see if children improve physically and psychologically.

The RENUEVATE study is a randomized controlled cluster trial with a parallel group design and repeated measurements, developed using a quantitative approach. The study follows the CONSORT guidelines for randomized cluster trials and has been approved by the Scientific Ethics Committee of the Catholic University of Maule, Chile (Resolution No. 112/2025). All procedures comply with the principles of the Declaration of Helsinki.

Randomization is performed at the educational establishment level in order to reduce the risk of contamination between participants. Three urban establishments in the city of Talca, Chile, representative of different administrative and socioeconomic contexts (municipal and privately subsidized), are randomly assigned to the intervention group (IG) or control group (CG). In each establishment, one sixth-grade class is assigned to the IG and another to the CG, making a total of six clusters.

Participants in the intervention group receive the RENUEVATE program, a school physical activity intervention integrated into regular physical education classes. The program is implemented during the academic period by previously trained physical education teachers, using a standardized manual that ensures the fidelity of the intervention. Teachers receive initial training and periodic supervision from the research team.

The intervention is based on the use of alternative sports (flag football, ultimate frisbee, korfball, and kin-ball), selected for their ability to promote moderate to vigorous physical activity, motor skill development, cooperation, inclusion, and gender equality. Each session follows a standardized structure that includes warm-up, main development, and cool-down phases, prescribing the intensity necessary to achieve adequate levels of physical effort during the central phase. The fidelity and dose of the intervention are monitored through session records, subjective perception of effort, and heart rate monitoring in a subsample of participants.

The control group continues with the regular physical education curriculum taught by the school, without modifications or exposure to the intervention content, participating only in pre- and post-intervention assessments.

Assessments are conducted at two points in time: before the start of the intervention (baseline) and at the end of the program, during the school day and by previously trained assessors, ideally blinded to group assignment. Primary and secondary outcomes include variables of physical fitness, motor skills, physical activity levels, body composition, enjoyment of physical activity, and health-related quality of life, assessed using validated instruments widely used in children. A detailed description of the variables and measurement instruments is presented in the corresponding sections of the registry.

The sample size was estimated to detect a clinically relevant difference in the percentage of body fat between groups, considering the cluster design and an expected intraclass correlation. Statistical analysis will be performed under the intention-to-treat principle, using mixed-effects models that allow for the hierarchical structure of the data and repeated measurements over time, adjusting for baseline values and relevant covariates. The procedures for handling missing data and sensitivity analyses are predefined in the study protocol.

The inclusion criteria for participants are as follows:

• Be enrolled in the assigned school.
• Have no motor problems that prevent participation in the physical activities proposed for the development of alternative sports.
• Have completed ≥ 85% of the sessions. The exclusion criteria
• Not having taken the initial or final tests.