Vg prima δb

Energy metabolism was measured in an airtight chamber (Fuji Medical Science, Chiba, Japan), which measured 2.00 × 3.45 × 2.10 m, with an internal volume of 14.49 m³. The chamber was furnished with a small window for blood sampling, bed, desk, chair, toilet, and cycle ergometer. The temperature and relative humidity of the incoming fresh air were controlled at 25.0 ± 0.5°C and 55.0 ± 3.0%, respectively. The oxygen (O₂) and carbon dioxide (CO₂) concentrations in the outgoing air from the metabolic chamber were measured using an online process mass spectrometer (VG Prima δB; Thermo Electron, Winsford, UK). Every 5 min, O₂ consumption (V˙ O₂) and CO₂ production (V˙ CO₂) rates were calculated using an algorithm providing an improved transient response (Tokuyama et al., 2009). Urine samples were collected for 24 h from 6:00 on day 2 to 6:00 on day 3, and urinary nitrogen excretion (N) was measured using the Kjeldahl method. Energy expenditure and macronutrient oxidation were calculated from the V˙ O₂, V˙ CO₂, and N values (Ferrannini, 1988) during the exercise bouts and for the total over 24 h. Energy balance was calculated by subtracting the total energy expenditure from the total energy intake for 24 h from 6:00 on day 2 to 6:00 on day 3.

HC was used to measure O₂ consumption and CO₂ production in a room-size indirect calorimeter (Fuji Medical Science Co., Ltd., Chiba, Japan), as previously described [15 (link)]. The concentrations of O₂ and CO₂ in the outgoing air were measured using online process mass spectrometry (VG Prima δB, Thermo Electron Co., Winsford, UK). The temperature and relative humidity in the calorimeter were maintained at 25 °C and 50%, respectively, and the air in the calorimeter was removed at 80 L/min. VO₂ and VCO₂ were calculated using the Brown algorithm; EE was calculated using VO₂, VCO₂, and Weir’s equation (EE = 3.9 × VO₂ (L) + 1.1 × VCO₂ (L)) [16 (link)]; and the respiratory exchange ratio (RER) was calculated as VCO₂/VO₂. The accuracy of the calorimeter for the measurement of EE, determined repeatedly using a 3 h alcohol combustion test, was 99.7% ± 1.5% for O₂ consumption and 100.1% ± 1.6% for CO₂ production during the study. PA level was calculated as: PA level = 24 h minus EE/RMR. RMR was estimated using a previously published equation [13 (link)].
Net exercise-induced EE during Mid-PA (walking) and High-PA (jogging) was calculated as: EE for 1 h, including the initial period of exercise minus EE during the equivalent Low-PA period.

Indirect calorimetry was performed with a room‐size indirect calorimeter (Fuji Medical Science Co., Ltd., Chiba, Japan). The calorimeter room measures the size with 2.00 m × 3.45 m × 2.10 m, having an internal volume of 14.49 m³. The chamber is furnished with an adjustable hospital bed, desk, chair, washing basin, and toilet. The air flow in the chamber was ventilated at a rate of 80 L/min. The temperature and relative humidity of the chamber were controlled and maintain with 25.0 ± 0.5°C and 55.0 ± 3.0%, respectively. Concentrations of oxygen (O₂) and carbon dioxide (CO₂) in the chamber were measured by online process mass spectrometry (VG Prima δB, Thermo Electron Co., Winsford, UK). Precision of mass spectrometry, defined as the standard deviation for continuous measurement of calibration gas mixture (O₂ 15%, CO₂ 5%), was < 0.002% for O₂ and CO₂. Hourly average of O₂ consumption (VO₂) and CO₂ production (VCO₂) rates were calculated using algorithm for improved transient response  (Tokuyama, Ogata, Katayose, & Satoh, 2009).
Energy expenditure and macronutrient oxidation were calculated from VO₂, VCO₂, and urinary nitrogen excretion (Ferrannini, 1988). Rate of urinary nitrogen excretion (N), an index of protein catabolism, was assumed to be constant during the calorimetry. Respiratory quotient (RQ) was defined as a ratio of VCO₂ to VO₂.

The airtight metabolic chamber measured 2.00 × 3.45 × 2.10 m (FHC-15S, Fuji Medical Science Co., Ltd., Chiba, Japan), and air in the chamber was pumped out at a rate of 80 L/min. The temperature and relative humidity of the incoming fresh air were controlled at 25 °C and 55%, respectively. The chamber was furnished with an adjustable hospital bed, desk, chair, and toilet. Concentrations of oxygen (O₂) and carbon dioxide (CO₂) in the outgoing air were measured with high precision by online process mass spectrometry (VG Prima δB; Thermo Electron Co., Winsford, UK). The precision of the mass spectrometry, defined as the standard deviation for continuous measurement of the calibrated gas mixture (O₂, 15%; CO₂, 5%), was 0.0016% for O₂ and 0.0011% for CO₂. Every minute, O₂ consumption ( $\dot{V}{\text{O}}_2$ ) and CO₂ production ( $\dot{V}{\text{CO}}_2$ ) rates were calculated using an algorithm for improved transient response^{40 (link)}. Energy expenditure was calculated from $\dot{V}{\text{O}}_2$ , $\dot{V}{\text{CO}}_2$ , and urinary nitrogen excretion (N), as described previously^{22 (link),39 (link),41 (link)}.