Study on the validation of the computer science application's activity monitor in assessing the physical activity among adults using doubly labeled water method / 中华流行病学杂志

ABSTRACT

<p><b>OBJECTIVE</b>Using doubly labeled water method to validate the colmputer science application's activity monitor (CSA) in assessing physical activity of free-living adults in Beijing, in order to develop equations to predict total daily energy expenditure (TEE) and activity related energy expenditure (AEE) from activity counts (AC) and anthropometric variables.</p><p><b>METHODS</b>A total of 72 healthy adults (33 males and 39 females, mean age 43.6 +/- 4.0 yr) were monitored for 7 consecutive days by CSA. TEE was simultaneously measured using doubly labeled water method. Average AC (counts/min(-1)) was compared with TEE, AEE and physical activity level (PAL).</p><p><b>RESULTS</b>Physical activity determined by AC was significantly related to data on energy expenditures TEE (r = 0.31, P < 0.01), AEE (r = 0.30, P < 0.05), and PAL (r = 0.26, P < 0.05). Multiple stepwise regression analysis showed that TEE was significantly influenced by gender, fat-free mass (FFM) or BMI and AC (R(2) = 0.52 - 0.70) while AEE was significantly influenced by gender, FFM and AC (R(2) = 0.25 - 0.32).</p><p><b>CONCLUSION</b>AC from CSA activity monitor seemed a useful measure in studying the total amount of physical activity in free-living adults while AC significantly contributed to the explained variation in TEE and AEE.</p>