Exercise and Endocannabinoids for Brain and Mental Health

This study will explore how exercise affects brain chemicals called endocannabinoids, which may improve thinking skills and reduce feelings of stress, anxiety, and low mood in children and teens aged 9 to 17. Participants will take part in a single 30-minute activity session, where they will be randomly assigned to one of three groups: 1. Moderate-intensity exercise (walking or running on a treadmill at 50-70% of their maximum heart rate). 2. Light stretching (gentle movements at less than 40% of their maximum heart rate). 3. Seated meditation (relaxing without movement at less than 30% of their maximum heart rate). The investigators will measure endocannabinoid levels, thinking skills, and mood before and after the activity to see how these activities affect the brain and emotions.