Physical Exercise Training to Enhance Executive and Social Functions
Condition: Broad Autism Phenotype
Study type: Interventional

Summary: 
      Background and study aims: Executive functions (EF) and social functions are important for
      self-regulation, problem solving, and attaining future goals yet they are impaired in Autism
      Spectrum Disorder (ASD). Physical exercise (PE) is found to enhance these central cognitive
      and social impairments in ASD. While limited research has begun to target these impairments
      in clinical samples, the presence of sub-clinical traits of ASD (refer to as broad autism
      phenotype (BAP)) in the general population is more common than the 1% prevalence of ASD.
      Therefore, it is crucial to study these impairments in the sub-clinical individuals. This
      study aims to investigate the effectiveness of PE in enhancing the EF and social functions in
      the BAP adolescents. Method: Participants will be recruited from the local community and they
      should be between the age of 7-20 years without any psychiatric disorders. Expected results:
      PE is predicted to be effective in reducing the EF and social impairments in these
      adolescents. Implications: These findings can inform us with the knowledge to design a
      community-based PE training targeting EF problems in these adolescents with BAP in the local
      context. Ultimately, this training can be incorporated to the curriculum of the primary and
      secondary schools targeting BAP and associated impairments in adolescents.
    

Detailed description: 
      Executive functions (EF) refer to goal-directed cognitive processes consisting of three major
      components including cognitive flexibility (mental flexibility), inhibition (inhibitory
      control) and working memory. These components interact with each other and play a crucial
      role in a range of life outcomes including mental and physical health, school and job success
      and marital harmony. In addition, higher EF is associated with better problem solving,
      reasoning and planning skills as well as social functions.

      Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterised by social
      communication and interaction impairments, as well as restricted and repetitive patterns of
      behavior. Individuals with ASD have EF impairments which are linked to the restricted and
      repetitive behaviors that characterise this condition. The prevalence of ASD is increasing
      with as many as 1 in 68 individuals, which further augments the burden to the ASD
      individuals, their families and society. Hence, it is essential to investigate the underlying
      mechanism of ASD and design a cost-effective training that can be widely adopted in the
      community to reduce impairments arising from ASD symptoms.

      Importantly, ASD traits occur on a continuum, and increasingly there is recognition of a
      broader autism phenotype (BAP) in those that show sub-clinical symptoms. Similarly, these
      individuals also show impairments in executive function and social functions, making this
      group an important target for the development and implementation of interventions. As such,
      we can deliver appropriate training at an earlier stage to prevent associated impairments in
      those with ASD traits. Therefore, instead of ASD, the present study examines the individuals
      with BAP.

      Given EF impairments along with social function deficits are found in the sub-clinical
      individuals with BAP, is the training pertaining to ASD applicable to these individuals? In
      prior literature, physical exercise (PE) has been proved to enhance EF and social functions.
      For instance, regular PE can enhance cerebral blood flow and increase the formation of new
      blood vessels in a number of brain regions that are involved in EF and social functions. More
      specifically, PE is shown to enhance the performance of EF in healthy children and
      pre-adolescents and those with ASD. For example, it was found that PE including jogging
      significantly decreased the repetitive and off-task behaviors and the level of aggression in
      individuals with ASD. Nevertheless, although PE is shown to be beneficial to reduce the
      symptoms and EF as well as social impairments in ASD, whether it produces the same positive
      outcomes in the non-clinical individuals. To address the research questions listed above,
      this proposed study aims to investigate whether PE training enhances the EF and social
      functions in the adolescents with BAP.

      Although the benefits of physical exercise have been studied in the ASD, BAP is under studied
      in prior literature. This proposed study will extend from the current literature to
      investigate the non-clinical group who have autistic traits with a longitudinal and
      randomized controlled trial design (RCT). The findings of this proposed study have multiple
      levels of significance and implications. For instance, if the hypotheses are supported, the
      PE training which is more cost-effective than psychotherapy in treating EF and social
      functioning deficits and associated impairments can be promoted to school settings.
      Ultimately, it can be incorporated to the curriculum of the primary and secondary schools to
      reduce BAP and associated impairments in the adolescents. Secondly, by examining those with
      sub- clinical symptoms, this research will contribute to early trainings approaches for the
      condition. Lastly, this proposed study can also help promote physical activities among
      adolescents which can further decrease mental and health issues in the local context.
    

Intervention name(s): Physical exercise (running on a treadmill)
Intervention type(s): Behavioral
Intervention description(s): Participants in the intervention group join a total of 12 treadmill running sessions, two sessions per week and each session for 30 minutes. In each session, every participant will be trained to run for 30 minutes on a treadmill. According to Exercise and Sports Science Australia (ESSA) exercise intensity guidelines, the intensity of running is suggested to be moderate and vigorous (alternating between the two) in this study.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: A total of 30 participants with BAP were randomly assigned to either groups: 1) intervention group (12 treadmill running sessions, two sessions per week and each session 30 minutes) and 2) control group: waitlist control group.
Masking: Single (Participant)
Primary purpose: Treatment
Keywords: physical exercise; social function; broad autism phenotype; executive function