Attention-Deficit/Hyperactivity Disorder (ADHD) is a lifelong neurodevelopmental disorder characterised by persistent symptoms of inattention, hyperactivity, and impulsivity. According to the DSM-5, these symptoms must be present for at least six months, have an onset in childhood, and result in significant impairment in multiple life domains. Although ADHD may be limited to childhood in some cases, most individuals continue to have symptoms and impairments in varying degrees in adult life. The prevalence of persistent ADHD among adults is estimated to be approximately 2.58%, depending on diagnostic criteria and sample selection. The increasing awareness of ADHD has led to a marked increase in referrals to mental health services, which places greater demands on the development of effective and accessible treatment options for this group.
Pharmacological treatment, particularly the use of stimulants, is a common intervention for adults with ADHD and has been shown to be effective for many. However, there are also side effects associated with drug treatment, and there is a need for more evidence-based non-drug alternatives. In addition, discontinuation of medication is common in ADHD treatment. Psychological interventions include psychoeducation and cognitive behaviour therapy, as well as more specialised approaches based on Dialectical Behaviour Therapy and Goal Management Training, which aim to improve executive functions. Whilst pharmacotherapy and psychotherapeutic interventions help some people with ADHD, not all people experience favourable outcomes, which calls for alternative treatment approaches. Interventions targeting the core symptoms of ADHD, executive functions, and behaviour are particularly relevant to treatment provision.
One approach to improving executive functioning that has received increasing attention is physical exercise. Studies have shown that physical activity can have a positive effect on cognitive function, executive control, and behaviour in children and adolescents with ADHD. Physical exercise may also be applied as treatment for comorbid factors common in ADHD, such as mood disorders and multiple long-term physical conditions. Despite increasing interest in physical activity as a treatment modality, research on physical exercise for adults with ADHD is still limited. The findings from studies on younger age groups point to the potential for similar effects in adults, but more research is needed to examine the effects of physical exercise as a targeted intervention in the adult population with ADHD.
Among the different types of physical activity, high-intensity interval training (HIIT) has gained promise for mental health. Due to its rapid, alternating, and fast-paced style, it could prove useful for those with ADHD. However, research on high-intensity interval training interventions (HIIT) in this population is scarce. To address these unanswered questions, this project will conduct a feasibility trial for a randomised controlled trial (RCT) to assess the feasibility and acceptability of HIIT among people with ADHD.