Exercise therapy is the most recommended treatment for chronic low back pain (LBP), with evidence supporting modest effects, likely due to the heterogeneity of patient presentations. Evidence suggests that matching individuals to the most appropriate exercise type could improve outcomes. Systematic reviews also emphasise that effective exercise interventions should be patient centred, target paraspinal muscle health and be of sufficient duration. This study addresses these gaps using a targeted care approach to identify a homogenous sample that is more likely to respond to our interventions. The inclusion of a sample with predominant nociceptive pain profile will be performed with the integration of the Pain and Disability Drivers Management Model (PDDM) and the Lumbar Spine Instability Questionnaire (LSIQ). The primary aim of this two-arm randomised controlled trial is to compare the effectiveness of motor control plus isolated lumbar extension exercises (MC+ILEX, arm 1) to free-weight resistance training (arm 2) in reducing LBP-related disability. Secondary aims include examining whether changes in multifidus composition mediate disability improvements comparing intervention effects on muscle size and quality, strength, mobility, pain, quality of life, sleep, physical activity and satisfaction; exploring baseline LSIQ scores and sex/gender as moderators of treatment response; and investigating participants’ perceptions and experiences of exercise therapy.

A total of 106 participants will be recruited through primary and secondary care and randomised (1:1) to receive either MC+ILEX or free-weight resistance training. Both groups will complete 48 exercise sessions over 16 weeks. The primary outcome will be disability at 16 weeks, measured by the Oswestry Disability Index. Secondary outcomes include multifidus muscle composition and size, lumbar and gluteal muscle strength, hip range of motion, pain, physical and mental function, satisfaction and recovery, health-related quality of life, sleep quality and physical activity levels. Linear mixed-effects models will be used to assess primary and secondary outcomes. Regression analyses will explore whether baseline LSIQ scores moderate treatment effects on multifidus composition and other outcomes. A subsample of participants will undergo semistructured interviews before and after the intervention to explore their illness perceptions, illness mindsets, perceptions of exercise therapy, as well as their experiences and satisfaction with the two exercise interventions. Reflexive thematic analysis will be used to analyse qualitative data.

This study received ethics approval from the Central Ethics Research Committee of the Quebec Minister of Health and Social Services (CCER-25-26-14). Results will be submitted to peer-reviewed journals and scientific meetings.

ISRCTN14864451.

Few studies have examined how psychosocial risk and protective factors in adolescence shape mental health outcomes and other multimorbid conditions in adulthood, particularly among Canadian youth. The Research on Eating and Adolescent Lifestyle (REAL) 2.0 study was a 15-year follow-up cohort study designed to investigate how early etiological factors, including body image and disordered eating symptoms in adolescence, contribute to the development of eating, weight-related concerns, mental health and substance use health problems in early adulthood. In this paper, we describe the REAL 2.0 cohort’s demographic and clinical characteristics alongside an overview of the study procedures, laying the groundwork for collaboration on future learnings with this unique data.

The cross-sectional REAL study initially surveyed middle and high school students from 2004 to 2010 (n=3043) across 43 schools in the Ottawa, Canada region. Of those, respondents in grade 7 or 9 (n=1197 from 25 of the 43 original schools) were asked to participate in a longitudinal arm of the study that consisted of yearly follow-ups. From the longitudinal cohort, there were 278 participants (29.1% male; M_age=28.6) from those who consented to be re-contacted (n=912), who completed the REAL 2.0 survey electronically (30.4%), providing comprehensive data on demographic, clinical, eating and weight-related behaviour, psychological, social, environmental and substance use health factors in adulthood.

9.4% of REAL 2.0 participants met DSM-5 criteria for an eating disorder, while 17.6% met criteria for disordered eating. Moderate to severe anxiety was reported by 28% of participants, while 21.6% experienced moderate to severe depressive symptoms. Regarding substance use, 16.9% engaged in hazardous drinking, 16.9% used cannabis daily or almost daily, and 4.3% reported daily tobacco use.

REAL 2.0 has the potential to answer multiple research questions about several mental health outcomes, but its priority focus is to answer questions related to risk and protective factors of multimorbidity in adulthood. Additionally, profiling work, linked to health service utilisation data for systems planning work and predictive modelling studies are secondary goals. By leveraging the Health Data Nexus (HDN) platform, we welcome collaboration with interested researchers who would like to utilise the breadth of data both in adolescence and adulthood to answer other pertinent aetiological questions in mental health and substance use health outcomes. Future plans to conduct additional follow-ups remain feasible.