Energy Cost of Reclining, Sitting, and Standing Activities in Chinese Adults

The 2011 Compendium presents MET values for sedentary behaviors (SBs) and light-intensity physical activities (LIPAs). Some entries have estimated METs, others have multiple activities in a single entry, and newer activities are not in the Compendium. Accurate MET values are needed to increase the validity and generalizability of the Compendium. This study measured and analyzed SBs and LIPAs' energy costs in reclining, sitting, standing postures, and fidgeting. Indirect calorimetry measured the energy costs (VO₂, ml·kg^-1.min^-1) in 11 males and seven females (30.7 ± 7.6 y). Two groups of 9 participants each completed 17 randomly assigned activities (9 in group 1; 8 in group 2) for 5 minutes with a 2-minute rest between tasks. Standard METs were calculated as VO₂ ml·kg^-1.min^-1/3.5 ml·kg^-1.min^-1. Results showed mean MET values for doing nothing (recline: 1.3, sit: 1.3. stand: 1.3); Watching TV on a mobile phone (recline: 1.3, sit: 1.3); Reading (recline; 1.5, sit: 1.0); Writing (recline: 1.5, sit: 1.3, stand: 1.3); Texting or viewing websites on a mobile phone (recline: 1.3, sit: 1.3, stand: 1.3); Fidgeting (sit hands only: 1.5, sit feet only: 1.8, stand hands and feet: 2.0); Typing (stand: 1.3). Measured vs. Compendium METs were the same for five SBs and LIPAs, higher for three SBs and LIPAs (by 0.2 METs), and lower for one SB (by 0.3 METs). In conclusion, the activities ranged from 1.0 to 2.0 METs, categorized as sedentary and light-intensity. Increasing the accuracy of Compendium MET values increases its utility for the correct classification of SB and LIPAs.