Anxiety is one of the most frequent comorbidities in children with ASD leading to poor clinical outcomes. Physical exercise has been shown to be a promising and easy to implement intervention for reducing anxiety. However, little is known about the feasibility and efficacy of physical exercise to reduce anxiety in children with ASD from underserved, low-income families. Children with ASD, ages 6 - 12 years old from low-income and Latino families will be recruited for the study and assigned to an exercise intervention group and a sedentary control group. The physical exercise program is an eight-week program, administered three times per week in small groups. Compliance, parent-rated anxiety, and salivary cortisol will be measured before and after completion of the exercise and control group interventions.

Inclusion Criteria:

• Autism Spectrum Disorder (ASD) Diagnosis 6-12 years old
• ≥ 93rd percentile on CBCL or total score of ≥ 25 on SCARED
• Able to attend 3x/week for 8 consecutive weeks
• Able to follow instructions
• CalOptima Insurance or Medicaid and ability to participate in moderate physical exercise

Exclusion Criteria:

• Danger to themselves or others
• Medical conditions that may pose a risk during exercise
• Unable to participate in moderate physical exercise
• Joining a regular physical exercise program in the last 4 weeks or planning to start or discontinue a regular physical exercise program in the next 8 weeks
• Unable to attend 3x/week for 8 consecutive weeks
• Visual, auditory or motor impairments, which would preclude participation in study activities