Characteristics and effects of school based physical activity programs for schoolchildren with autism spectrum disorder: A scoping review

. Although benefits have been reported from the practice of physical activity in children with autism spectrum disorder (ASD), to a lesser extent the characteristics of the programs carried out in the school context and their effects on health are known. The objective of this review was to characterize school based physical activity programs and their effects on the health of schoolchildren with ASD. The review was carried out in accordance with the PRISMA statement in the databases, Medline and PsycINFO, between the years 2010 to 2023. A total of 20 articles were analyzed. A total sample of 683 schoolchildren with ASD ( x ̄ =10.5 years and 73.1% male) were included. Schoolchildren with ASD had 98.1% adherence to the programs. The school based physical activity programs were mainly based on aerobic exercises, such as walking, jogging, running, and cycling (45% of the articles) with a duration between 10-16 weeks (55% of the articles), with a frequency of 2-3 times a week (60% of the articles) and with 60-minute sessions (45%). On the other hand, the most studied variables were language and motor skills (60% of the articles) and psychosocial and cognitive function (50% of the articles); together with the variables of physical and nutritional activity, these were where a higher percentage of articles with positive effects were found. The findings suggest a profile of schoolchildren with ASD and the main characteristics of school based physical activity programs in schoolchildren with ASD in terms of their extension, frequency, duration, intensity, location and provider as well as the variables most frequently evaluated and with the greatest positive effects.


Introduction
Autism Spectrum Disorder (ASD) is characterized by difficulties in the development of social skills, restricted interests, repetitive behaviors (Sanchack, 2016), and a readability sedentary lifestyle, In addition, they present deficits in relevant areas of development and schooling such as social interaction, verbal and non-verbal communication, creative play, sensory processing, maintaining eye contact and adapting to noisy environments (Sowa & Meulenbroek, 2012;Maravé-Vivas, Carregui Ballester, Gil-Gómez & Chiva-Bartoll, 2021). According to The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), the diagnostic criteria for ASD are: A. Persistent deficits in social communication and social interaction across multiple contexts, as manifested by the following symptoms , current or past (Deficits in socialemotional reciprocity; Deficits in nonverbal communica-tive behaviors used in social interaction; Deficits in developing, maintaining, and understanding relationships), B. Repetitive and restricted patterns of behaviors, activities, and interests, which manifest themselves in at least two of the following symptoms, current or past (Stereotyped or repetitive motor movements, use of objects, or speech; Insistence on equality, inflexible adherence to routines or ritualized patterns of verbal and nonverbal behavior; Highly restricted interests, obsessive , which are abnormal in intensity or focus; Sensory hyper-or hypo-reactivity or unusual interest in aspects of the environment), C. The symptoms must be present in the early developmental period, D. The symptoms cause clinically significant disturbances socially, occupationally, or in other important areas of current functioning, and E. These disturbances are not better explained by the presence of an intellectual disability or a global developmental delay (DSM-5, 2014). Reporting an increase in ASD during the last decades, with a prevalence of 1.5% in developed countries (Sharma et al., 2018;Waye & Cheng, 2018;Rech, Irwin, Rosen, Baldwin & Schenkelberg, 2022). In this sense, schoolchildren with ASD do not achieve the minimum levels of physical activity recommended (i.e. 60 minutes of daily physical activity throughout the week mainly moderate to vigorous intensity aerobic) (WHO, 2020). Besides, there is evidence that indicates that the adolescent population is readability more sedentary than the adult population (Menear & Neumeier, 2015;Pan et al., 2016).
The foregoing is of interest, since metabolic and cardiovascular diseases related to physical inactivity have a high prevalence in the population (Bilder et al., 2013;Croen et al., 2015). In this sense, physical activity is a protection and prevention factor associated with better physical and psychological health (Biddle & Asare, 2011;Hillman & Biggan, 2017), and that plays a crucial role in promoting and maintaining a healthy lifestyle in adolescents with ASD (Fang et al., 2019;Jones et al., 2017). In addition, studies indicate that physical activity has positive effects on the control of stereotypical behaviors (i.e., involuntary, coordinated, non-purposeful and rhythmic movements that are carried out in an identical way in each repetition, as well as improvements in motor skills, social relationships with their schoolmates and inclusiveness (Pérez-Dueñas, 2010; Chiva-Bartoll, Maravé-Vivas, Salvador-García y Valverde-Esteve, 2021). socioemotional, cognitive, and attention functioning in young adults belonging to this population have been observed (Yu et al., 2018;López Díaz, Moreno Rodríguez y López Bastías, 2021). Along these lines, the current literature emphasizes the need to identify and design programs that promote physical activity in the adolescent population with ASD (Liang et al., 2020a;Sorensen & Zarrett, 2014).
As such, the educational context has been proposed as an ideal means for the promotion of physical activity, through various moments of the school day, such as physical education classes, recesses, the school classroom, sports practice, and extracurricular activities, which allow maximizing the functional independence and quality of life in children and young adults with ASD (Langford et al., 2015;Fernández Cabrera, Jiménez Jiménez, Navarro Adelantado y Sánchez López, 2019;Muñoz Moreno, Smith, y Matos Duarte, 2020). In this sense, physical activity programs (i.e. any programs that includes any body movement produced by skeletal muscles that involves expenditure of energy (WHO, 2018)) at school have been suggested as a particularly useful means to develop and increase interest and participation in physical activity in this population (Bremer et al., 2020), allowing the introduction of behavior modification techniques through this type of programs (Fessia et al., 2018). However, the characteristics of physical activity programs that contribute to the comprehensive health of children and young adults with ASD in educational contexts are unknown.
Based on this background, the following research questions were asked: What are the characteristics of school based-physical activity programs aimed at students with ASD? and What are the effects of these programs on the health of schoolchildren with ASD? Along these lines, the objective of this scoping review was to characterize school based-physical activity programs and their effects on the health of schoolchildren with ASD. This review will make it possible to identify a profile of the physical activity programs and identify the main variables and procedures that have been applied during the last decade.

Search Strategy
This scoping review was carried out according to the guidelines established by the PRISMA statement (Liberati et al., 2009). The PRISMA checklist can be found in the supplementary material (Table S1). The manuscript was not registered in PROSPERO. PROSPERO does not currently accept registrations for scoping reviews, literature reviews or mapping reviews.
The search strategy followed the Peer Review of Electronic Search Strategies (PRESS) (McGowan et al., 2016) guidelines. A systematic search was carried out in May 2020 and updated in February 2023, with MeSH terms "Exercise", "Autistic Disorder", and "Schools". The general search syntax was: ("physical activity" OR "exercise" OR "sport") AND (autism spectrum disorder) AND (school OR school-based programs). The MEDLINE databases were reviewed by PubMed and PsycINFO. The objective was to identify studies that use school based physical activity programs in schoolchildren who present ASD. The search covered the period from 2010 to February 2023. The complete search strategy in all databases is presented in the supplementary material (Table S2).

Selection of studies and inclusion
Exclusion criteria by gender were not applied (studies conducted in men and women were accepted), but language was considered, and only articles in English were reviewed. Reviews, editorial documents, protocols, or theses were not included. Physical activity programs combined with educational activities or physical activity carried out outside the educational center were not included. The articles selected by title and abstract had to meet the conditions indicated in

Data Extraction
In the first step, identified duplicate articles were removed from the databases using Mendeley software version 1.19.4. Then, two reviewers (CG-A and NU-C) applied the inclusion/exclusion criteria to all titles and abstracts. Articles that met the inclusion criteria were selected, and when decisions could not be made based on the title and abstract alone, the full-text documents were also retrieved. The selected articles were independently verified by the two reviewers (CG-A and NU-C); and when there were discrepancies, a third reviewer made the decision (MC-C). We used a standardized questionnaire to extract the data from the included articles to synthesize the evidence.

Risk of bias assessment tools and the Consensus on Exercise Reporting Template (CERT) assessment format
We analyzed the risk of bias in all included full-text articles. "The Cochrane Collaboration's tool for assessing risk of bias in randomized trials" by Higgins et al., (2011) for Randomized Clinical Trials, evaluating the risk of bias in each of the proposed items: (a) Selection bias, (b) Performance bias, (c) Detection bias, (d) Attrition bias and (e) Reporting bias. The only item that was not considered was "Other biases". The results of this analysis are presented, grouping all the studies analyzed (Table S3) and ROBINS-I (Risk of Bias in Non-randomized Studies of Interventions) was used to analyze the risk of bias (Sterne et al., 2016) for non-randomized studies (Table S4). Each article was independently graded by two reviewers (CG-A and NU-C) and scores were compared. When there was a disagreement, a consensus was reached with a third reviewer (MC-C). In addition, the Consensus on Exercise Reporting Template (CERT) evaluation form was added to determine the proportion of articles that met the CERT items. In the results section, a description of these analysis was presented, and detailed analysis is in supplemental material (Slade, S.C. et al., 2016) (Table S5).

Strategy for data synthesis
A narrative synthesis of the findings was provided from the included studies, and the main information is presented in Tables 2, 3, and 4. The results were organized by: general characteristics of the articles (Author, year, country, gender, age, design, and main aim, and adherence, i.e., which can be understood as maintaining a regimen or exercise program for an extended period after an initial phase of adaptation has been completed (Lox et al., 2014)) ( Table   2), characteristics of physical activity programs for schoolchildren with ASD (Table 3) and main effects on study variables and measurement instruments used (Table 4). Figure 1 presents the flow chart for systematic reviews proposed by the PRISMA Declaration. A total of 548 potential articles were identified. Subsequently, after the exclusion of duplicates in the databases, the selection and eligibility criteria were applied. Finally, 20 articles were included for the narrative synthesis in this review (

Overview of included articles
Of the total of articles, the period with the highest frequency of publication was between the years 2016 to 2019 with 14 of 20 articles. Of a total of eight countries, the United States was the country with the highest frequency of articles found (8 of the 18 articles). A total of 683 schoolchildren with an average age of 10.5 years completed the school physical activity programs (n=499; 73.1% male), achieving a total adherence of 98.1% (Table 2). To investigate the effectiveness of the video prompting procedure on teaching aquatic play skills and to determine the effects of aquatic exercise training on the motor performance of children with ASD.

Risk of bias assessment tools and the Consensus on Exercise Reporting Template (CERT) assessment format
Risk of bias in nine randomized trials was assessed using The Cochrane Collaboration's tool for assessing risk of bias in randomized trials. The risk of bias was included for each of the items proposed by the Cochrane Collaboration's tool. A high percentage of articles had a low risk of bias in the selection bias for the sequence generation (91%), as well as for the attrition bias (100%) and reporting bias (100%). In contrast, a high percentage of articles with unclear risk in performance bias (82%) and high risk in detection bias (91%) and allocation concealment (82%) were observed (Table S3). In addition, risk of bias for nine non-randomized studies was assessed using ROBINS-I. In the overall risk of bias, 6 articles had a moderate risk of bias, 2 a low risk of bias and 1 a serious risk of bias (Table  S4).

Characteristics of school based physical activity programs
Of the total articles, the duration and frequency of the programs implemented most frequently was between 10-16 weeks (11 articles), two or three times a week (12 articles). In addition, the duration of sessions most frequently was 60 minutes per session (9 articles). The place of school programs where it was used most frequently was the school and special schools (7 and 9 articles, respectively) and the higher education center (4 articles). In 15 of 20 articles, the school programs were carried out by a specialized professional (psychologist, speech pathologist, or differential educator). The type of physical activity implemented consisted mainly of aerobic exercises (9 articles), (e.g., walking, jogging, running, and cycling) that trained motor skills. In addition, 7 articles included sports which were more frequently activities in the water environment, or swimming (4 articles), multi-sport (2 articles), and karate (2 articles) ( Table 3).

Measurement instruments and main effects of school based physical activity programs on schoolchildren health with ASD
The variables were grouped into 5 categories. The first group corresponds to the physical activity variables (which included physical activity level and intensity, physical and cardiorespiratory fitness, calories, and dance performance), present in 5 articles and positive effects were found in 4 of them. The second group was of body composition variables (which included BMI, waist-hip circumference, and skin folds) present in 3 articles and did not present positive effects. The third group were the psychosocial and cognitive function variables (which included social functioning and family, manifestations related to physical activity capacities in children, social, physical and health behaviors, autistic behaviors and social response, social interaction, emotion regulation, behavioral functioning, and executive function) present in 10 articles with positive effects found in 8 of them. The fourth group were the nutritional status (which included water and vegetable consumption, nutritional behavior, and confectionery consumption) present in 2 articles and finding positive effects in both, and the fifth group were language and motor skills (which included, speech, language, communication, body awareness, spatial and body concepts, motor aptitude, aquatic skills, basic language, learning skills, and stereotypical behaviors) present in 12 articles and positive effects were found in 11 of them (Table 4).

Main findings
The main findings of this scoping review indicate that the 20 articles included a total sample of 683 schoolchildren with ASD (73.1% male) and with an average age of 10.5 years. The schoolchildren with ASD had an adherence to the program of 98.1%. The studies were carried out mainly in primary or special schools (56% of the articles) and guided by a specialized professional (75%). The school based physical activity programs were mainly based on aerobic exercises, such as walking, jogging, running, and cycling (45% of the articles), with a duration between 10-16 weeks (55% of the articles), with a frequency of 2-3 times a week (60% of the articles), and with 60-minute sessions (45%). The most studied variables were language and motor skills (60% of the articles) and psychosocial and cognitive function (50% of the articles). Together with the variables of physical and nutritional activity, they were where a higher percentage of articles with positive effects was found.

Findings of the review and contrast with the existing evidence
Characteristics of school based physical activity programs It has been suggested a low participation of students diagnosed with ASD in school spaces aimed at performing physical activity. In this regard, Recent evidence has shown that children and adolescents with ASD are less physically active than their typical development peers (Liang et al., 2020b). However, based on this, it is analyzed and affirmed that physical activity improves the health and quality of life of the population evaluated. The quality of the comprehensive school programs of physical education and / or physical activity can play a much more significant role for those students who present ASD, since the environment that exists in the school context can offer the opportunity to promote the development of skills and / or essential skills for students to be more active and energetic and, at the same time, to be able to make a transcendent contribution to the general levels of physical exercise in the school population (Bremer et al., 2020).
The school is a primary space to promote and carry out programs aimed at increasing the participation of physical activity, exercise, or sport since the integral development of the students is promoted and / or strengthened mainly in the educational establishment due to their extensive performance in it during the year. Before this, Bremer et al. (2020) points out that through the opportunity to be more active in educational centers, it is possible to encourage and / or favor students who present ASD to develop safety and enjoyment skills, to be more active outside of school. Likewise, these physical exercises, carried out in educational establishments, contribute to the general levels of physical activity, being able to contribute to the students to comply with the physical activity guidelines.
However, with respect to the main characteristics of the programs, the highest percentage of professionals responsible for the evaluation corresponds to qualified personnel, followed by instructors and, finally, personnel from the health area. On the other hand, the total program time most used was 16 weeks (6 of 24). Regarding the weekly sessions, the majority were carried out in 2 or 3 sessions, with an average time of 67 minutes, with 60 minutes being the most used period. Regarding the components of the programs, they were grouped into 3 categories: physical exercises, corresponding to different voluntary body movements; sports activities that considered those sports subject to established norm and / or rules, and finally, recreational activities corresponding to activities of entertainment, distraction and fun.
The time within a program is essential to meet objectives and develop skills, as highlighted by Schmitz, et al., (2017) through their study, based on participants selected by the presentation of self-stimulation and other inappropriate behaviors. Results show that shorter and less intense periods of exercise were more effective in reducing stereotypical behaviors, while the more exhaustive exercise session led to an increase in frequency (Schmitz Olin et al., 2017).

Effects of school based physical activity programs in schoolchildren health with ASD
Regarding the effects or results obtained in responses to the programs, they showed as evidence a major decrease in stereotypical behaviors, as supported by Bahrami, Moheda, Marandi & Abedi (2012) through the analysis of the participation of students in karate techniques for a period of 4 months, exhibiting a reduction of stereotypical behaviors in the diagnosed students. Likewise, it occurs with the involvement of the students in dance sessions and choreography twice a week (Bahrami et al., 2012;Lakes et al., 2019).
On the other hand, motor development as a sequential and continuous process demands the development of motor skills in students with ASD, what might be needed to create spaces where they can enhance these skills. In the studies by Colebourn, Golub-Victor & Paez (2017), El-Garhy & Liu (2016, and Hilton et al. (2014) they show a range of activities that favor the increase, improvement or progression of these skills, such as throwing games, movement of the body and arms, catching the ball, hitting objects, and running in a training period between 30 to 60 minutes, obtaining a significant improvement in perceptual motor skills, upper limb coordination, visual motor control, balance, speed, dexterity, and strength (Colebourn et al., 2017;ElGarhy & Liu, 2016).
In relation to body composition, specifically body mass index, An, DuBose, Decker & Hatala (2019) after the participation of the students for 4 months in the program "I can't do it'', not only analyzes the program from a purely physical perspective through exercises, but also shows information on the increase in nutritional variables, such as the consumption of water and healthy foods . Performing basic exercises that involve consistent strength training, such as squats and push-ups, directly improve health and physical condition, as well as activities such as walking and playing soccer for 60 minutes, causing improvements in blood pressure, walking distance, moderate physical activity, and progressions in body mass index, fitness, and cardiovascular healessiah et al., 2019).
Finally, in reference to the evaluation of social variables, we showed that eight studies carried out programs aimed at evaluating the communication deficit, social functioning, participation, socialization, among others, where in most of the results obtained there were improvements and progression. Bahrami, Movahedi, Marandi & Sorensen (2016) through their appreciation of the participation of students with an ASD diagnosis in karate technique sessions, with an estimate of 30 to 90 minutes, four times a week, results in a significant reduction in the communication deficit (Bahrami et al., 2016). The same occurs with the assessment provided by the authors Miltenberger & Charlop (2014) where games such as handball and four tables promote speech, group play and participation. The inquiries regarding the social sphere, carried out by the different authors, propose that programs based on activities where social interaction is required among its participants, such as swimming, soccer, table tennis, and athletics between 15 to 60 minutes are effective in increasing these skills (Miltenberger & Charlop, 2014).

Limitations of this study
First, we highlight that the review does not comprise a meta-analysis of the included studies. The synthesis of the information presented has a qualitative approach, which generates a limitation to determine the effectiveness of physical activity programs in health outcomes of schoolchildren with ASD.
Second, experimental and quasi experimental studies were included, thus showing great heterogeneity in methodological quality and a high risk of bias.
Third, despite efforts to conduct comprehensive searches, this review may not have found all relevant studies. This may be due to the variability in the search terms used, the lack of access to certain databases or the lack of publication of some studies. Besides, only articles written in English were considered, which could have hidden articles published in other languages or in places where English is not a primary or commonly spoken language such as Latin America or the Caribbean.
Fourth, the highest risk of bias reported by the Cochrane tool was related to performance bias and detection bias. Both biases are associated with difficulty in masking participants and study staff. These biases increase the risk that the knowledge of the intervention received will affect the results, which could lead to a systematic error in the application of school based on physical activity programs. It is relevant to highlight that numerous investigations indicate the low methodological quality of the studies; other studies mention a high risk of bias in at least one domain evaluated.
Fifth, it is possible that new articles could be published after the search ended in February 2023.
Finally, it is relevant to indicate that the results of this review may not be generalizable to all schoolchildren with ASD, educational centers or physical activity programs. Therefore, it is important to consider the limitations and conditions in which the research found was conducted when interpreting the results of this review.

Clinical and research implications
The results obtained in this scoping review suggest that physical activity plays an important role in the well-being and development of schoolchildren with ASD.
School is the privileged place where schoolchildren develop in a constant way. In this context, this review shows that school based on physical activity programs can promote benefits in physical development, language and communication skills, emotional well-being, socialization, attention, executive functions, as well as in the reduction of problematic behaviors. We highlight the progression of motor skills, exhibiting an evident decrease in stereotypical behaviors commonly attributed to this disorder, as well as the parameters most commonly used in the studies are presented. Hence, we believe that these findings could be useful to professionals working with schoolchildren with ASD for a safe and timely prescription of future school based on physical activity programs.
It is important that parents and caregivers working with teachers and health professionals can identify, select, and promote appropriate and effective physical activities, exercises, or sports for each schoolchild with ASD.
Considering that most of the physical activity programs were carried out by specialized professionals (speechlanguage pathologist, psychologist, physical therapist, physical education teacher or differential educator) and that they were carried out in special schools, it is highly relevant that these professionals are trained in the prescription of physical exercise.
Additionally, we allow ourselves to deliver the following suggestions to professionals who develop these physical activity programs in school contexts a) communicate with parents and educational team to adapt the contents of the program, b) create safe and structured environments that provide confidence for the realization of physical activity routines, c) provide clear and positive feedback so that students with ASD know if they are doing the activities well and feel motivated to continue participating, and d) be flexible and patient in the design and content of the programs, since all students with ASD are unique and may have different needs and ways of learning.

Future lines of research
The authors of this review encourage researchers to investigate the effects of physical activity-based school programs on the health of schoolchildren with ASD. It is suggested to analyze whether there are elements or conditions in school that promote physical activity in schoolchildren with ASD (example: health and education professionals who work directly with schoolchildren with ASD, availability of time and spaces for physical activity, use of school uniform). It is suggested to study if there are policies or educational programs that promote physical activity programs in schoolchildren with ASD for example, active breaks, curricular content adapted to develop them active-ly). Finally, it is suggested to analyze if there are signs and symptoms of ASD that benefit more from physical activity programs.

Conclusions
The 20 studies included in this scoping review showed a profile of schoolchildren with ASD and the main characteristics of school based physical activity programs in schoolchildren with ASD in terms of their extension, frequency, duration, intensity, location and provider. This review showed the variables and instruments most frequently used in research on schoolchildren diagnosed with ASD.
In addition, this review synthesizes the main positive effects of physical activity divided into 5 categories; physical activity, body composition, psychosocial and cognitive function, nutritional status, and language and motor skills.

Authors' contributions
CG-A, NU-P, MC-C and RZ-L proposed and designed the review and drafted the manuscript. CG-A, NU-P, MC-C and RZ-L conducted the searches, reviewed the findings, and discussed and agreed studies to be included. AT, AR, DR-M, MC-A, CO and IC contributed to the manuscript. All authors have read, commented on and approved the final manuscript.