Examination of oxygen uptake kinetics in decremental load exercise by a numerical computation model.
The purpose of this study was to establish a numerical computation model for estimation of oxygen uptake (V(.)O2) kinetics in decremental load exercise (DLE) starting from a work rate (WR) above the ventilatory threshold (>VT). In the model, WR in DLE were separated into several steps (constant load exercise, CLE) of which the durations increased step by step. V(.)O2 kinetics in each step was estimated using an exponential equation, and the sum of VO2 values from all steps at a given time was regarded as simulated V(.)O2 in DLE. In the model, the time constants were set symmetrically in a step <VT and asymmetrically in a step >VT at onset and offset (tau(off)) of exercise. As a result, simulated V(.)O2 qualitatively, but not quantitatively, approximated measured V(.)O2. Consequently, we incorporated a new model in which a step >VT was subdivided into several parts. Although there was a slight difference quantitatively, the interval of subdivision of 3.0 min and tau(off) of 2.8 min allowed for qualitative approximation. The numerical computation model adopted in this study is useful for estimation of V(.)O2 kinetics during DLE starting from high intensity (>VT).
Laboratory of Exercise Physiology, Health and Sport Education, Graduate School of Education, Hokkaido University. arimitsu@edu.hokudai.ac.jp
Takuma
T
Arimitsu
Ryouta
R
Matsuura
Takehide
T
Kimura
Takahiro
T
Yunoki
Tokuo
T
Yano
D000328:Adult; D003198:Computer Simulation; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007700:Kinetics; D008297:Male; D008954:Models, Biological; D018482:Muscle, Skeletal / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology*; D012119:Respiration