Validity of Dynamic Prediction Model for Oxygen Uptake during Supra Maximal Intermittent Load Exercise

Abstract

The purpose of this study was to determine the validity of a dynamic prediction (DP) model that predicts oxygen uptake (VO₂) during supra maximal intermittent (SMI) exercise based on non-linearity of VO₂ dynamics in comparing a heart rate (HR) model. Five male participants (20±1 yrs) performed incremental exercise test used by cycle ergometer for the aim of developing individualized HR- VO₂ and workload- VO₂ regression equations. The DP model was defined as a first order system to workload- VO₂ relationship. Participants then completed SMI test corresponding at 140 % VO₂max while HR and VO₂ data were collected continuously for 20 min. The HR model predicted VO₂ during SMI test used by HR, while the DP model also predicted VO₂ from workload. Predicted values (VO₂) were compared with measured values (VO₂) obtained via a metabolic measurement system. The DP model showed a significantly higher relationship with measured VO₂ (R² = 0.95, SEE = 149 ml/min) in comparison with the HR model (R² = 0.83, SEE = 275 ml/min). The HR model showed significant systematic error (r = 0.41, P < .05), whereas the DP model did not (r = 0.06, P > .05). For comparison of prediction errors of both models, the error of the DP model (-1.3±8.8 %) was significantly smaller than the HR model (-8.0±16.5 %). The DP model also accurately estimated total energy expenditure. Therefore, the DP model is an accurate predictor of VO₂ during supra maximal intermittent exercise.