The objective of this study is to use a randomized controlled design to determine whether cardiorespiratory fitness training improves neurocognitive function and academic performance during preadolescent development.

The long term objective of this project is to develop an understanding of lifestyle factors that influence the cognitive and brain health of children while also reducing the sedentary nature of today's youth. Previous research has found that physical activity interventions can enhance both a variety of aspects of cognition and brain structure and function of children, older adults, and individuals with neurodegenerative disorders such as Parkinson's disease and multiple sclerosis. More specifically, in previous research with children the researchers have found that higher fit children possess larger hippocampi which in turn are related to better relational memory than their lower fit counterparts. The researchers have also observed that higher fit children exhibit more efficient executive control as indicated by performance measures and event-related brain potentials. While intriguing, these cross-sectional data do not enable us to establish causality between physical activity and cognition. In the current study the researchers substantially extend this previous research by examining the influence of a 9 month randomized controlled afterschool physical activity program on cognition and brain health. Cognition will be assessed with a battery of tasks and standardized achievement tests both before and after the 9 month intervention in the activity group and a wait list control (who will receive the intervention the following year). Children will also participate in magnetic resonance imaging (MRI) sessions both before and after the intervention (and at comparable times for the wait list control). In these sessions the researchers will measure both structural aspects of the brain including regional volumes of gray matter and the integrity of the white matter tracts (through diffusion tensor imaging) and functional aspects of brain function using fMRI activity recorded as the children perform a series of executive control and memory tasks. The researchers anticipate, based on our cross-sectional studies with children and our previous longitudinal studies with older adults, that the children in the physical activity program will show both larger regional brain volumes, particularly in brain regions that subserve executive control and relational memory, and more efficient brain function, as indexed by task-related and resting state fMRI. Furthermore, the researchers anticipate that these changes will be accompanied by improvements in memory and executive control processes. Given recent trends identifying decreased levels of physical activity and health status in preadolescents, the understanding of the potential benefits of physical activity on cognition is of great interest. It is imperative that factors positively influencing cognitive function of children be examined to maximize health and effective functioning of individuals as they progress through the lifespan.

Inclusion Criteria:

• Parental/guardian consent
• 8 - 9 years old
• Capable of performing exercise
• Absence of school-identified learning disability
• IQ >= 85
• Tanner Scales score <= 2
• ADHD Rating Scales score >= 85%
• Right hand dominant
• Absence of metal implants
• Not claustrophobic

Exclusion Criteria:

• Non-consent of guardian
• Above or below 8 - 9 years old
• Any physical disability that prohibits exercise
• School-identified learning disability
• IQ < 85
• Tanner Scales score > 2
• ADHD Rating Scale score < 85%
• Left hand dominant
• Presence of metal implants
• Claustrophobic