JMIR Publications

ABSTRACT

Background:

Sit-to-stand and treadmill desks may help sedentary office workers meet the physical activity guideline to “move more and sit less,” but little is known about their long-term impact on altering the accumulation patterns of physical behaviors.

Objective:

To explore the impact of sit-to-stand and treadmill desks on physical behavior accumulation patterns during a 12-month, cluster-randomized multi-component intervention with an intent-to-treat design in overweight and obese seated office workers.

Methods:

Sixty-six office workers were cluster-randomized into a seated-desk control (N= 21; 8 clusters), sit-to-stand desk (N= 23; 9 clusters), or treadmill desk (N= 22; 7 clusters) group. Participants wore an activPALTM accelerometer for 7-days at baseline, month-3 (M3), month-6 (M6), and month-12 (M12) and received periodic feedback on their physical behaviors. Physical behavior patterns were analyzed for the total waking-day and workday, and included: i) daily number of sedentary, standing and stepping bouts categorized into bout durations ranging from 1-60 and >60 min, and ii) usual sedentary, standing and stepping bout durations. Intervention trends were analyzed using random-intercept mixed linear models accounting for repeated measures and clustering effects.

Results:

Compared to controls, sit-to-stand desk-users had shorter usual sedentary bout durations short-term [total-day M3 Δ: -10.1 min/bout (95% CI: -17.9,-2.2); workday M3 Δ: -20.3 min/bout (95% CI: -37.7,-2.9)], while treadmill desk-users had longer usual sedentary bout durations long-term [total-day M12 Δ: 9.0 min/bout (95% CI: 1.6,16.4)]. Differences stemmed from the treadmill desk group favoring prolonged sedentary bouts (>60 min), while the sit-to-stand desk group accrued more short-duration sedentary bouts (<20 min). Relative to controls, treadmill desk-users had longer usual standing bout durations short-term [total-day M3 Δ: 6.9 min/bout (95% CI: 2.5,11.4); workday M3 Δ: 8.9 min/bout (95% CI: 2.1,15.7)] and sustained this long-term [total-day M12 Δ: 4.5 min/bout (95% CI: 0.7,8.4); workday M12 Δ: 5.8 min/bout (95% CI: 0.9,10.6)]. Whereas sit-to-stand desk-users showed this trend only in the long-term [total-day M12 Δ: 4.2 min/bout (95% CI: 0.1,8.3)]. Differences were likely due to the treadmill desk group favoring prolonged standing bouts (30-60 min and >60 min), while the sit-to-stand desk group accrued more short-duration standing bouts (<20 min). Treadmill desk-users had longer usual stepping bout durations short-term compared to controls [workday M3 Δ: 4.8 min/bout (95% CI: 1.3,8.3)] and short- and long-term compared to sit-to-stand desk-users [workday M3 Δ: 4.7 min/bout (95% CI: 1.6,7.8); workday M12 Δ: 3.0 min/bout (95% CI: 0.1,5.9)]. Differences stemmed from the treadmill desk group accumulating more stepping bouts across various bin of durations (5-50 min), primarily at M3.

Conclusions:

Sit-to-stand desks exerted potentially more favorable physical behavior accumulation patterns than treadmill desks. Future active-workstation trials should consider strategies to promote more frequent long-term movement bouts and dissuade prolonged static postural fixity. Clinical Trial: ClinicalTrials.gov ID No.: NCT02376504