What is the metabolic and energy cost of sitting, standing and sit/stand transitions?

Pedro B. Júdice, Marc T. Hamilton, Luís B. Sardinha, Theodore W. Zderic, Analiza M. Silva

Modern lifestyles require people to spend prolonged periods of sitting, and public health messages recommend replacing sitting with as much standing as is feasible. The metabolic/energy cost (MEC) of sitting and standing is poorly understood, and MEC associated with a transition from sitting to standing has not been reported. Thus, we carefully quantified the MEC for sitting, standing and sit/stand transitions, adjusting for age and fat-free mass (FFM) in a sample of adults with no known disease. Participants (N = 50; 25 women), 20-64 years, randomly performed three conditions for 10 min each (sitting, standing, 1 sit/stand transition min(-1) and then sitting back down). MEC was measured by indirect calorimetry and FFM by dual-energy X-ray absorptiometry. V̇O2 (ml kg(-1) min(-1)) for sitting (2.93 ± 0.61; 2.87 ± 0.37 in men and women respectively), standing (3.16 ± 0.63; 3.03 ± 0.40), and steady-state cost of repeated sit/stand transitions (1 min(-1)) (3.86 ± 0.75; 3.79 ± 0.57) were significantly different regardless of sex and weight (p < 0.001). EE (kcal min(-1)) also differed from sitting (1.14 ± 0.18; 0.88 ± 0.11), to standing (1.23 ± 0.19; 0.92 ± 0.13), and sit/stand transitions (1 min(-1)) (1.49 ± 0.25; 1.16 ± 0.16). Heart-rate increased from sitting to standing (~13 bpm; p < 0.001). Neither sex nor FFM influenced the results (p ≥ 0.05). This study found in a sample of adults with no known disease that continuous standing raised MEC 0.07 kcal min(-1) above normal sitting. The transition from sitting to standing (and return to sitting) had a metabolic cost of 0.32 kcal min(-1) above sitting. Therefore, public health messages recommending to interrupt sitting frequently should be informed of the modest energetic costs regardless of sex and body composition.