A feasibility study of high intensity interval training intervention in inpatient mental health settings

Severe mental illnesses (SMI) are associated with physical health comorbidities. High intensity interval training (HIIT) may improve cardiometabolic risk and mental wellbeing for people with SMI. This study explores the acceptability and feasibility of implementing HIIT amongst inpatients with SMI. The feasibility study followed a two-part design: a) A randomized controlled trial (RCT) of bicycle-based HIIT versus treatment-as-usual (TAU). TAU comprised provision of details of the relevant hospital gym availability. This RCT was terminated early due to Covid-19 restrictions. b) A naturalistic study of inpatient HIIT. Acceptability and feasibility of the HIIT intervention across both study phases was reported. 32 people were recruited, 19 RCT and 13 naturalistic study participants. The early termination resulted in a maximum of 4 weeks of HIIT per RCT participant. Mean satisfaction with HIIT was 8.52/10. The full length of the HIIT session was completed in 77.3% and 71.9% of instances during the RCT and naturalistic phases respectively. Attendance at HIIT sessions averaged 62.9% in the RCT. HIIT was met with high satisfaction. Attendance to HIIT is comparable to attendance of other exercise regimes. This research supports the development of a large-scale trial of HIIT for inpatients with SMI to determine its health benefits. Trial registration ClinicalTrials.gov, registration no: NCT03959735.