Inclusion Criteria:  Children between 8 and 11 years old (inclusive) Girls and boys Children enrolled in CM1a and CM1b classes at the Pierre Brossolette school in Riom and in CM1/CM2 and CM2 classes at the Sévigné-Lafaye school in Vichy. Able to provide informed consent to research participation Registered in the French social security system  Exclusion Criteria:  Medical or surgical history judged by the investigator to be incompatible with the study Any unstabilised chronic pathology Inability to pedal Inability or contraindication to physical activity Subjects with cardiorespiratory and/or osteoarticular disorders that limit their ability to perform physical tests or use the cycle desks Subjects with a progressive cardiovascular or neoplastic disease. Subjects with a major infection in the 3 months prior to inclusion Subject with chronic or acute inflammatory disease in the 3 months prior to inclusion Subject diagnosed and/or treated for schizophrenia, bipolar disorder, major depression Person under guardianship, curatorship or not subject to a social security scheme Refusal to sign written consent to participate by the participant or a parent or guardian