This is a 16-week, structured, in-person physical activity intervention for children with ASD. The program consists of three 40-minute sessions per week delivered on-site at a partner school by certified physical education instructors. The curriculum is manualized and includes an Individualized Motor Protocol, Structured Group Sessions, and Behavior Change Support. Instructors provide direct, hands-on correction and feedback during sessions, adjusting task difficulty in real-time to match each child's individual capabilities and needs.

This is a minimal intervention control. Participants in this group do not receive a structured or guided physical activity program. At the beginning of the study, caregivers are provided with a one-time, webinar-style session on general pediatric health topics (e.g., nutrition, sleep hygiene) and an exercise guidance manual. These materials are for optional, independent use by the caregivers, and no active monitoring or follow-up is provided by the research team regarding their use.

Description: This metric represents the total amount of time spent in moderate-to-vigorous physical activity (MVPA), typically expressed in minutes per day. MVPA is derived from objective movement data collected by a wearable device and classified using a prespecified algorithm or cut points that distinguish moderate-to-vigorous activity intensity from light activity and sedentary time. This metric quantifies activity intensity exposure rather than sleep-related outcomes.

Parent sleep quality will be assessed using the Pittsburgh Sleep Quality Index (PSQI). This 19-item self-report measure generates seven component scores: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction. The sum of these seven component scores (each rated 0-3) creates a global PSQI score that ranges from 0 to 21, with higher scores indicating poorer sleep quality (a more negative outcome).

This parameter quantifies the period of time, measured in minutes, from the designated "lights out" or the beginning of the sleep attempt, to the first epoch of consolidated sleep. This is determined through an algorithmic analysis of movement data from the wearable accelerometer, which identifies the transition from an active wakeful state to a sustained resting state. SOL is a critical objective measure of sleep initiation. A prolonged SOL is a hallmark symptom of sleep-onset insomnia, making it a valuable outcome for assessing difficulties in falling asleep.

The average total time per day spent in physical activities of moderate-to-vigorous intensity. This outcome is objectively quantified using a wearable accelerometer and is a key indicator of health-enhancing physical activity levels.

The Children's Sleep Habits Questionnaire (CSHQ) is a parent-reported tool designed to assess sleep behaviors in children aged 4 to 12. It comprises 45 items covering eight subscales: bedtime resistance, sleep onset delay, sleep duration, sleep anxiety, night wakings, parasomnias, sleep-disordered breathing, and daytime sleepiness. Parents rate each item based on frequency over the past week, using a 3-point scale: "usually" (5-7 times), "sometimes" (2-4 times), or "rarely" (0-1 time). A higher total score indicates more sleep problems. The CSHQ has demonstrated good reliability and validity in identifying pediatric sleep disorders.

This metric represents the percentage of time spent asleep relative to the total time a person spends in bed, calculated as (Total Sleep Time / Time in Bed) x 100. The data is objectively derived from continuous actigraphy recordings captured by a wearable accelerometer. As a primary indicator of sleep consolidation, a higher sleep efficiency percentage signifies more continuous, high-quality, and less fragmented sleep. It is a key objective marker for evaluating overall sleep quality and the effectiveness of interventions aimed at improving restorative sleep.

Parental mood will be assessed using the Hospital Anxiety and Depression Scale (HADS). It contains 14 items, divided into a 7-item Anxiety subscale and a 7-item Depression subscale. Items are rated on a 4-point scale (0-3) based on the intensity or frequency of symptoms. Each subscale score ranges from 0 to 21, where higher scores indicate greater symptom severity for anxiety and depression, respectively (a more negative outcome).

Parenting-related stress will be evaluated using the Parenting Stress Scale (PSS). This 17-item scale measures the level of stress experienced by parents by assessing both positive and negative aspects of their parenting role. Participants rate their agreement with each statement on a 5-point scale. The total score ranges from 17 to 85, with higher scores indicating a greater level of parenting stress (a more negative outcome).

Perceived social support will be assessed using the Multidimensional Scale of Perceived Social Support (MSPSS). This 12-item scale evaluates an individual's perception of social support. Each item is rated on a 7-point scale (1 'Very Strongly Disagree' to 7 'Very Strongly Agree'). The total score ranges from 12 to 84, where higher scores indicate a greater level of perceived social support (a more positive outcome).

Parental quality of life will be evaluated using the World Health Organization Quality of Life-BREF (WHOQOL-BREF). This 26-item instrument is a shorter version of the WHOQOL-100, assessing four domains: Physical Health, Psychological Health, Social Relationships, and Environment. Items are rated on a 5-point scale. For analysis, domain scores are calculated and transformed to a scale ranging from 0 to 100, where higher scores indicate a better quality of life (a more positive outcome).

Behavioral problems will be assessed using the Behavior Problems Inventory . This 52-item instrument evaluates challenging behaviors across three subscales: Self-Injurious Behavior, Stereotyped Behavior, and Aggressive/Destructive Behavior. Each item is rated for frequency and severity on a 4-point scale from 0 (not a problem) to 3 (a severe problem). For this study, the total BPI score, representing the sum of all 52 items, will be used for analysis. The total score ranges from 0 to 156, with higher scores indicating a greater severity of behavior problems (a more negative outcome).

Description: This metric represents the total amount of time spent in sedentary behavior (SB), typically expressed in minutes per day. SB is derived from objective movement data collected by a wearable device and classified using a prespecified algorithm or cut points that distinguish sedentary time from light and moderate-to-vigorous physical activity. This metric quantifies low-movement waking behavior rather than sleep or physical activity intensity.