Integrating high-intensity interval training into the workplace: The Work-HIIT pilot RCT.

Abstract

The purpose of this study was to assess the feasibility and preliminary efficacy of a high-intensity interval training (HIIT) intervention integrated into the workplace on physical and mental health outcomes in a sample of adults. The Work-HIIT intervention was evaluated at the University of Newcastle (March-July 2019). University employees (18+years) who self-identified as predominantly sedentary at work (n=47, 43.0±10.7years; 41 female) were recruited, screened, and randomized after baseline assessments into Work-HIIT (n=24) or wait-list control (n=23) conditions. Participants were asked to attend 2-3 researcher-facilitated HIIT sessions/week (weeks 1-8). Sessions included a 2-minute gross-motor warm-up, followed by various combinations of aerobic and muscular fitness exercises lasting 8minutes (using 30:30second work: rest intervals). Program feasibility was assessed using measures of satisfaction, compliance, adherence, fidelity, and retention. Physiological and psychological outcomes were measured at baseline and 9weeks. Feasibility data were investigated using descriptive statistics and efficacy outcomes determined using linear mixed models and Cohen's d effect sizes. Participant ratings showed high levels of satisfaction (4.6/5); 71% of participants attended ≥2 sessions/wk and averaged 85.9% HRmax across all sessions (including rest and work intervals). Small-to-medium positive effects resulted for cardiorespiratory fitness [+2.9 laps, 95% CI (-4.19-10.14); d=0.34] and work productivity [+0.26, d=0.47]. Large positive effects resulted for muscular fitness [push-ups +3.5, d=0.95; standing jump +10.1cm, d=1.12]; HIIT self-efficacy [+16.53, d=1.57]; sleep [weekday +0.76hours, d=1.05]; and autonomous motivation [+0.23, d=0.76]. This study supports the feasibility and preliminary efficacy of facilitator-led Work-HIIT as a time-efficient, enjoyable, and convenient workplace exercise option for adults.