1. 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) = aEEmax (J/min) height (meter)
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):
[3] Chen KY, Sun M. Improving energy expenditure estimation by using a triaxial accelerometer. Journal of Applied Physiology. 1997;83(6):
Acknowledgements
Research was funded by NMC(NMC 2013-MS-02) and NRF( ) in South Korea