AbstractCardiovascular disease is a leading cause of morbidity and mortality, with a multitude of modifiable risk factors including poor physical fitness, cardiometabolic and mental health. Exercise training is an effective strategy that can improve important cardiometabolic and mental health outcomes. High-intensity interval training (HIT) is a form of exercise training that can elicit physiological and psychological adaptations similar to traditional prescriptions of moderate intensity exercise; however the majority of research to date has been confined to laboratory environments, and as such the effectiveness of HIT outside of the laboratory is unclear. One setting in which the effectiveness of HIT is beginning to be explored is the workplace. Accordingly, this thesis describes a mixed methods programme of work with the overall aim of exploring the effects of workplace-based HIT on markers of physical fitness, cardiometabolic and mental health in employees.
Firstly, a systematic review is presented aiming to quantify the effects of workplace exercise interventions on cardiorespiratory fitness. Here, random effects meta-analysis demonstrated meaningful improvements in cardiorespiratory fitness, post-intervention. Subsequently, a qualitative formative evaluation explored the feasibility and acceptability of a proposed workplace-based HIT trial named Brief Exercise at Work (BE@Work), with data used to further develop the BE@Work protocol. Accordingly, the acute physiological and psychological responses to novel HIT modes selected by formative evaluation participants were explored in a randomised cross-over trial. As the novel modes of HIT elicited physiological responses indicative of high-intensity exercise, they were incorporated into a controlled feasibility trial of an 8-week workplace-based HIT intervention.
The BE@Work trial was advertised in two workplaces where ~400 individuals were employed. Seventy-seven individuals responded to recruitment attempts (global emails, presentations in meetings and taster sessions) and were assessed for eligibility. Fifty four participants completed baseline testing. Outcome measures were cardiorespiratory fitness (Chester step test); leg extensor muscle power (Nottingham Leg Rig); hand grip strength (hand dynamometer); blood pressure (automatic monitor); blood lipids and glucose (finger-prick point-of-care testing), body mass index, waist circumference and questionnaire assessed health-related quality of life, psychological wellbeing and perceived stress. All outcome measures were assessed in the workplace. With the exception of the Nottingham Leg Rig, the assessment methods were found to be feasible and acceptable for data collection in a workplace. The Nottingham Leg Rig, is heavy and cumbersome which caused difficulty during transportation of the equipment, and noise from the device disturbed the working environment.
During the BE@Work trial 20 (±3) out of 24 possible workplace HIT sessions were attended (range: 14 to 24 sessions). Post-intervention, meaningful improvements were observed in cardiorespiratory fitness, two domains of health-related quality of life and perceived stress, compared with control. There were no meaningful effects on markers of muscular fitness, anthropometry, blood pressure, blood lipids and glucose or psychological wellbeing. The findings of this thesis demonstrate that novel modes of HIT can be feasibly incorporated into a workplace-based exercise intervention capable of eliciting improvements in important markers of physical fitness and mental health. However, it is acknowledged that the BE@Work trial was exploratory in nature and used a predictive assessment of cardiorespiratory fitness and therefore the implementation of a definitive multi-site RCT is warranted before stronger conclusions can be made about the feasibility and effectiveness of workplace-based HIT.
|Date of Award||21 Feb 2020|
|Supervisor||Kathryn Weston (Supervisor), Greg Atkinson (Supervisor) & Matthew Weston (Supervisor)|