The effect of high-intensity interval training on cognitive function in patients with substance use disorder: Study protocol for a two-armed randomized controlled trial.

Introduction: Substance use disorder (SUD) is characterized by cognitive impairment, especially executive dysfunction. Executive function is recognized as an important determinant of treatment outcome as it is associated with dropout rate, attendance to therapy and potential relapse after treatment termination. Physical activity can have beneficial effects on cognitive function, but there is still a lack of knowledge regarding potential benefits of aerobic exercise for executive function in SUD treatment. The aim of this study is to examine the effect of aerobic high-intensity interval training (HIIT) on cognitive function and the subsequent effect on treatment outcome in patients with SUD. Methods and analysis: This study is a randomized controlled trial, including men and women ≥18 years with diagnosed SUD by ICD-10. The patients will be recruited from the department for inpatient treatment at Blue Cross - Lade Addiction Treatment Center, Trondheim, Norway. Participants will be randomized 1:1 into either HIIT (3x/week) + treatment as usual (TAU), or TAU alone. Study outcomes will be assessed at baseline, after eight weeks of intervention, and at 3- and 12-months follow-up. The primary outcome is to compare the change in executive function (via altered BRIEF-A score, Behavior Rating Inventory of Executive Function-Adult) measured between the two study groups after eight weeks. Secondary outcomes include mapping of cognitive function in different subgroups (e.g. type of substance, age, fitness level), collecting self-reported information about quality of life, craving, sleep quality, etc., as well as assessing compliance to TAU and long-term treatment outcome. Ethics and dissemination: The project was approved by the Regional Ethical Committee and will be performed in accordance with this protocol and the Declaration of Helsinki. Written informed consent will be obtained from all participants prior to inclusion. This project will explore a novel approach to how exercise can be applied in SUD treatment, beyond the well-known effects on physical health. We expect to achieve new knowledge in regard to what extent HIIT can improve cognitive abilities and subsequent treatment outcome in SUD. Trial registration number: https://www.clinicaltrials.gov/NCT05324085.

Cardiopulmonary and muscular effects of different doses of high-intensity physical training in substance use disorder patients: study protocol for a block allocated controlled endurance and strength training trial in an inpatient setting.

INTRODUCTION: Patients with substance use disorder (SUD) have high prevalence of lifestyle-related comorbidities. Physical exercise is known to yield substantial prophylactic impact on disease and premature mortality, and there seems to be an inverse association between physical fitness and adverse health outcomes. High-intensity training is regarded as most effective for improving physical fitness, but less is known concerning the ideal training dose necessary to achieve clinically relevant effects in these patients. The aim of this study is to compare the effect of low-dose and high-dose, high-intensity training, on physical fitness in patients diagnosed with SUD. METHODS AND ANALYSIS: This study will recruit 40 in-patients of mixed genders, aged 18-70 years. Participants will be block allocated to low-dose or high-dose training, encompassing 24 high-intensity interval and maximal strength training sessions (3/week × 8 weeks). After a 10 min warm-up, the low-dose group will perform 1×4 min intervals at ⁓90% of maximal heart rate and 2×4 repetitions strength training at ⁓90% of 1 repetition maximum. The high-dose group will perform 4×4 min intervals at ⁓90% of maximal heart rate and 4×4 repetitions strength training at ⁓90% of 1 repetition maximum. Clinical measurements and physical tests will be conducted at baseline, midway and on completion and a questionnaire on physical activity will be administered at baseline. ETHICS AND DISSEMINATION: This protocol is in accordance with the Standard Protocol Items: Recommendations for Interventional Trials statement. All participants will sign a written informed consent. The Regional Committee of Medical Research Ethics, Norway has approved the study. A study of this kind is warranted, and the results will be published in an open access journal to ensure public access, and presented at national and international conferences. TRIAL REGISTRATION NUMBER: NCT04065334.