RESUMO
BACKGROUND: Recent guidelines recommend accruing 2-4h of standing or light activity during the working day. Use of sit-stand desks could achieve this goal, but whether standing can meaningfully increase energy expenditure (EE) is unclear. AIMS: To study EE, heart rate, feelings and productivity during deskwork while sitting, standing or alternating positions. METHODS: We measured EE by indirect calorimetry in working adults over three randomly ordered 60-min conditions while performing deskwork: continuous sitting (SIT), 30min of each standing and sitting (STAND-SIT) and continuous standing (STAND). We also assessed heart rate, productivity and self-reported energy, fatigue and pain. Linear mixed models compared minute-by-minute EE and heart rate across conditions. Non-parametric tests compared remaining outcomes across conditions. RESULTS: The study group comprised 18 working adults. Compared with SIT, STAND-SIT engendered an additional 5.5±12.4 kcal/h (7.8% increase) and STAND engendered an additional 8.2±15.9 kcal/h (11.5% increase) (both P < 0.001). Alternating positions to achieve the recommended 4h/day of standing could result in an additional 56.9 kcal/day for an 88.9kg man and 48.3 kcal/day for a 75.5kg woman. STAND-SIT and STAND also increased heart rate over SIT by 7.5±6.8 and 13.7±8.8 bpm, respectively (both P < 0.001). We observed no meaningful differences in feelings or productivity. CONCLUSIONS: Desk-based workers could increase EE without added discomfort by using a sit-stand desk. These findings inform future research on sit-stand desks as a part of workplace interventions to increase EE and potentially improve health.