The BE@Work (Brief Exercise at Work) trial: Effects of workplace-based high-intensity interval training on physical fitness, cardiometabolic health and wellbeing in office workers

High-intensity interval training (HIT) can improve markers of physical fitness and cardiometabolic health (MacInnis & Gibala, 2017).The chronic impact of HIT on psychological variables is understudied (Stork et al. 2017) and the effectiveness of HIT in workplaces is unclear. We quantified the effects of our Brief Exercise at Work (BE@Work) intervention, comprising 8-weeks of workplace-based HIT, on outcomes related to physical fitness, cardiometabolic health and wellbeing in office workers. METHODS: Using a controlled trial design, 55 office-based employees (mean age ± standard deviation [SD] 46 ± 11 years) were recruited from two workplaces in Northeast England; one as an intervention site (n = 31), the other as no-treatment controls (n = 24). The 8-week intervention comprised of thrice-weekly workplace-based HIT sessions consisting of 4 to 7 60-s maximal effort intervals interspersed with 75-s rest, based on stair stepping, stair climbing and non-contact boxing. Outcomes assessed at baseline and post-intervention were cardiorespiratory fitness (VO2max), leg extensor muscle power, handgrip strength, body mass index, waist circumference, blood pressure, blood lipids and glucose, eight domains of health related quality of life (HR-QoL) (Short Form 36 HR-QoL questionnaire; Hays et al. 1993), psychological wellbeing (Warwick Edinburgh Mental Wellbeing Scale; Tennant et al. 2006) and perceived stress (Perceived Stress Scale; Cohen & Williamson, 1988). Data were analysed using an ANCOVA model (covariates; sex, age, outcome baseline value and hours fasted [blood variables only]). Using magnitude-based inferences, we calculated the probability of intervention effects as beneficial, trivial, and harmful against a threshold of the minimum clinically important difference of 1mL·kg-1·min-1 for VO2max and 0.2 between subject SDs for all other outcomes. Effects were only declared clear when the probability likelihood for the effect was ≥75% (i.e. likely). Data are presented as mean ±90% confidence limits. RESULTS: Mean HIT session attendance was 83%. Post-intervention there was a likely beneficial increase in VO2max (3.9 mL·kg-1·min-1 ±3.4 mL·kg-1·min-1) in intervention participants compared to controls. For domains of HR-QoL, there was a likely beneficial effect on energy/ fatigue (8.5 arbitrary units [AU] ±5.8 AU) and general health (4.6 AU ±4.1 AU), and a likely negative impact on bodily pain (-7.9 AU, ±10 AU). There was a likely beneficial decrease in perceived stress (-2.5 AU ±2.5 AU). There were no clear changes in any other outcomes post-intervention. CONCLUSION: This is the first trial to show that novel workplace-based HIT has clinically relevant beneficial effects on VO2max, and positively impacts on domains of HR-QoL and perceived stress. An increase in bodily pain may be due to muscle soreness from the HIT intervention. Improvements in markers of employee wellbeing may be particularly meaningful to organisations planning to implement similar programmes in the future.