High Intensity Training for Adults With ADHD in Specialised Mental Health Care

Participants will be invited to an in-depth interview lasting approx. 45 minutes, after the treatment intervention. The aim is to explore experiences with physical exercise in relation to core symptoms of ADHD. A semi-structured interview protocol with open questions and additional probes is used to promote exploratory dialogue on the participants experience with participation. All interviews will be audio recorded and transcribed verbatim. By comparing the individual accounts, we want to identify both patterns of commonalities and differences in participants' experiences, providing important descriptions of patient experiences that may contribute to detect challenges with the intervention that can be utilised for further development and implementation.

Six sub tests from the general ability test Wecshler Adult Intelligence Scale will be used to assess General Ability Index, Verbal Comprehension Index and Perceptual Reasoning Index.

The six subtests are: Block Design, Similarities, Matrix Reasoning, Vocabulary, Digit Span and Coding.

The Adult ADHD Self-Report Scale (ASRS) is a patient-reported outcome measure assessing the frequency and severity of adult ADHD symptoms. Items are rated on a 5-point Likert scale (0-4), with higher total scores reflecting greater ADHD symptom severity. Lower scores reflect fewer self-reported ADHD symptoms.

The Working Memory Questionnaire (WMQ) is a patient-reported outcome measure designed to assess everyday difficulties related to working memory functioning. It evaluates the frequency of memory-related problems experienced in daily life, including difficulties with remembering information, maintaining attention, following instructions, and managing cognitive tasks.

The WMQ consists of items rated on a Likert-type scale, where participants indicate how often they experience specific working memory difficulties. A total score is calculated by summing item responses. Higher scores indicate greater perceived working memory difficulties and a higher level of impairment in everyday cognitive functioning. Lower scores indicate fewer reported working memory problems and better perceived working memory functioning.

The total WMQ score is calculated by summing responses across items (with item scoring depen

The Generalized Anxiety Disorder-7 (GAD-7) is a patient-reported outcome measure assessing anxiety symptom severity. Items are scored from 0-3 based on symptom frequency over the previous two weeks, producing a total score from 0-21. Higher scores indicate greater anxiety symptom severity, while lower scores indicate fewer anxiety symptoms

The Patient Health Questionnaire-9 (PHQ-9) is a patient-reported outcome measure assessing depressive symptom severity. Items are scored from 0-3 based on symptom frequency over the previous two weeks, producing a total score from 0-27. Higher scores indicate greater depressive symptom severity, while lower scores indicate fewer depressive symptoms.

The Bergen Insomnia Scale (BIS) is a patient-reported outcome measure assessing insomnia symptoms and sleep-related impairment. Six items are rated from 0-7 according to symptom frequency over the previous month, producing a total score from 0-42. Higher scores indicate greater insomnia symptom severity, while lower scores indicate fewer insomnia symptoms.

The International Physical Activity Questionnaire (IPAQ) is a patient-reported outcome measure assessing physical activity and sedentary behavior. It measures frequency and duration of walking, moderate-intensity, and vigorous-intensity activities over a specified recall period. Scores are calculated as MET-minutes/week, with higher scores indicating greater physical activity and lower scores indicating less physical activity.

The Work and Social Adjustment Scale (WSAS) is a patient-reported outcome measure assessing functional impairment associated with a health condition. Five items are rated from 0-8, producing a total score from 0-40. Higher scores indicate greater impairment in work, social, and daily functioning, while lower scores indicate better functioning.

The Adult ADHD Quality of Life (AAQoL) is a validated self-report questionnaire designed to assess health-related quality of life in adults with attention-deficit/hyperactivity disorder (ADHD). The instrument evaluates the impact of ADHD symptoms on daily functioning and well-being across multiple domains, including life productivity, psychological health, relationships, and outlook.

The AAQoL consists of 29 items, each rated on a Likert-type scale reflecting the frequency or severity of difficulties experienced over a specified recall period. Item responses are combined and transformed into domain scores and an overall total score.

Item responses are aggregated and converted to standardized scores ranging from 0 to 100 for the total scale and each domain. Higher scores indicate better health-related quality of life, while lower scores indicate poorer quality of life and greater ADHD-related f

The Credibility/Expectancy Questionnaire (CEQ) is a patient-reported measure assessing perceived treatment credibility and expectancy for improvement. It consists of 5 items where patients rate themselves on a likert scale from 0-10. It produces a total scores, with higher scores indicating greater perceived credibility and stronger expectations of treatment benefit.

The Negative Effects Questionnaire - Short Form (NEQ-S) is a patient-reported outcome measure assessing perceived negative or unwanted effects of an intervention. Higher scores indicate a greater number and/or severity of self-reported adverse effects.

The Wechsler Memory Scale - Third Edition (WMS-III) Spatial Memory subtest is a clinician-administered measure of visuospatial memory. Standardized age-adjusted scores are derived, with higher scores indicating better spatial memory performance and lower scores indicating poorer spatial memory.

The D-KEFS Trail Making Test is a clinician-administered measure of executive function assessing visual scanning, processing speed, and cognitive flexibility. Performance is measured by time to completion and standardized scaled scores, with higher scores (and faster completion times) indicating better executive functioning."

The D-KEFS Color-Word Interference Test is a clinician-administered measure of executive function assessing response inhibition and cognitive flexibility. Performance is measured by time to completion and standardized scaled scores, with higher scores (and faster completion times) indicating better executive functioning.

Maximal strength is assessed using the one-repetition maximum (1RM) test for lower-body and upper-body strength. In this study, maximal lower-body strength is assessed using a leg strength exercise (e.g., leg press or squat depending on protocol), and upper-body strength is assessed using the bench press.

The primary outcome is the maximal load lifted successfully for one repetition, recorded in kilograms (kg). Separate 1RM values are obtained for leg strength and bench press.

Higher scores: Indicate greater maximal muscular strength and neuromuscular performance in the tested muscle groups.

Lower score

Maximal oxygen uptake (VO₂max) is an estimate of the maximum rate at which oxygen can be utilized during intense aerobic exercise and is a key indicator of cardiorespiratory fitness. In this study, VO₂max is estimated using the Myworkout GO mobile application (Helgerud et al., 2022), which derives VO₂max from performance data collected during a standardized treadmill-based interval protocol (4×4 endurance session).

The estimation is based on recorded treadmill speed and incline during the exercise session, which are used to model aerobic capacity according to validated predictive algorithms.

VO₂max is reported as an estimated continuous variable in milliliters of oxygen per kilogram of body weight per minute (mL·kg-¹·min-¹). Higher values indicate greater aerobic capacity and cardiorespiratory fitness, while lower values indicate reduced aerobic fitness.