ESTIMATION OF CARDIOPULMONARY FITNESS DURING DAILY LIFE Chiyul Yoon1, Joong-Woo Ahn1, Eunjeh Hyun1, Hee Chan Kim2 and Hyung-Jin Yoon2 1Interdisciplinary Program of Bioengineering, Seoul National University Graduate School, Seoul, Korea 2Department of Biomedical Engineering, Medical Research Center, Seoul National University College of Medicine, Seoul, Korea Ⅰ. Introduction Figure 2 Scatter plot of the aEE and HR of the same subject. maximum aEE (aEEmax) was estimated with the maximal HR determined by age (220-age) A. Physical activity and Physical fitness Physical activity: any bodily movement produced by the skeletal muscles Physical fitness: a set of attributes that people have or achieve that is related to the ability to perform physical activity Cardiopulmonary fitness (CPF): abilities of the cardiovascular and pulmonary systems to provide adequate oxygen CPF is represented by maximum uptake of oxygen(VO2max) Activity tracker ≠ Fitness tracker Develop VO2max estimation model Independent value: Measured VO2max Dependent values: aEEmax, anthropometric values B. Conventional CPF(VO2max) measurments Type Description Disadvantage Maximal exercise test Gold standard With gas analysis Invasive Special equipment Submaximal exercise test Using heart rate or endurance time Familiarization problem Non-exercise estimation Using physical activity parameter Inaccurate in self-reported physical activity Need long measurement duration Ⅲ. Results VO2max (mL/min/kg) = 0.103 aEEmax (J/min) - 31.952 height (meter) + 92.532. R=0.88, adjusted R2= 0.75, and SEE= 2.51 mL/min/kg, p<0.001). Figure 3 Comparison between measured and estimated VO2max C. New CPF(VO2max) estimation method Developed a non-intrusive VO2max estimation system for use in daily life Activity energy expenditure, Hear rate (HR), and anthropometric value were used to develop a regression model to estimate VO2max. Ⅱ. Methodology Measurement of VO2max with Bruce protocol Worn unified ECG and accelerometric physical activity sensor during 4 days Ⅳ. Discussion Our method needs only 15 hours daily activity without any protocol It is the shortest period compared with previous studies which using heart rate and physical activity to estimate VO2max Limitation Homogeneous participants No validation Further study Heterogeneous participants Validate the model Heart rate and activity energy expenditure (aEE) [3] were calculated in every 1 minute. In the figure 1, the range where HR increases was only considered for aEEmax estimation. Ⅴ. Reference Figure 1 aEE and HR of one subject [1] Plasqui G, Westerterp KR. Accelerometry and heart rate as a measure of physical fitness: Proof of concept. Medicine and science in sports and exercise. 2005;37(5):872-6. [2] Cao ZB, Miyatake N, Higuchi M, Ishikawa-Takata K, Miyachi M, Tabata I. Prediction of VO2max with daily step counts for Japanese adult women. European journal of applied physiology. 2009;105(2):289-96. [3] Chen KY, Sun M. Improving energy expenditure estimation by using a triaxial accelerometer. Journal of Applied Physiology. 1997;83(6):2112-22. Acknowledgements Research was funded by NMC(NMC 2013-MS-02) and NRF(2005-2001287) in South Korea