Effectiveness of a smartphone directed physical activity program on cardiometabolic disease risk in desk-based office employees – A pragmatic, two-arm, parallel, cluster randomised trial

Background. Excessive uninterrupted sitting is found to be associated with increased cardiometabolic disease risk in desk-based employees. Point-of-choice prompts using a smartphone application (SmPh-app) may be a feasible method of promoting physical activity and negating cardiometabolic disease risk. The study aims to investigate the effectiveness of SmPh-app directed walk reminders on cardiometabolic disease risk (Fasting Blood Glucose (FBG), aerobic capacity (VO2 max) and Heart Rate Variability (HRV) in desk-based office employees. Methods. In this pragmatic, two-arm, parallel, cluster randomised trial, desk-based employees (n=53) of five administrative offices (clusters) of a university were randomised to two groups: SMART group in which employees were provided with SmPh-app based (six) walk reminders during working hours and CONTROL group in which employees continued their usual work. As FBG, VO2 max and HRV data were skewed, nonparamet-ric statistical analyses were used for intention-to-treat analysis. Results. Of 53 desk-based employees initially included in the trial, 47 completed the four weeks trial. Employees in SMART group showed a statistically significant difference in FBG (p < 0.001), VO₂ max (p < 0.05) and nearly all domains (time, frequency and non-lin-ear) of HRV (pre-vs. post-intervention) compared to CONTROL group. SMART group employees were found to reduce FBG by 8 mmol/dL (interquartile range (IQR):-12.25 to-3.75 mmol/dL), improve VO2 max by 2.23 ml/kg/min (IQR: 0.12 to 4.34 ml/kg/min) and improve HRV in all the domains compared to CONTROL group. Conclusions. SmPh-app based walk reminders improved FBG, functional capacity and HRV in desk-based office employees.