Consideration of the estimating method of oxygen demand in rowing

Abstract

Oxygen demand (OD) during supramaximal exercise is estimated by using linear relationship between power output (PO) and VO₂ in submaximal exercises. In rowing, stroke rate (SR) rises curvilinearly against PO and achieves to about twofold in supramaximal exercise compared with submaximal. However it’s not considered in estimating. The aim of this study was to investigate the estimating method of OD in rowing with considering the influence of increasing SR. Ten male collegiate rowers (age: 20.6± 2.8 yrs, height: 174.7± 4.9cm, weight: 71.1±8.9 kg) participated in this study. They performed submaximal exercise tests in normal condition (N-Con) and increased SR condition (SR-Con) to estimate OD during 90 seconds rowing test that rowed in same PO of their 2000 m time trial. In N-Con, subjects freely chose SR in each stage. In SR-Con, SR was fixed as increasing linearly against PO. Moreover, we tried to correct OD by using physical activity level that determined by integrals of absolute value of the accelerometer output (IAA). OD estimated in SR-Con (OD_SR:7.0 ± 0.8 lO₂Eq) and corrected by IAA (OD_IAA: 7.0 ± 0.7 lO₂Eq) were significantly larger than OD in N-Con (OD: 6.6 ± 0.8 lO₂Eq). In addition, there was not significant difference between OD_SR and OD_IAA, and they showed significant higher intra-class correlation coefficient (ICC (1, 1) = 0.93). These results suggested that OD in rowing is able to be corrected by fixing SR as linear increasing against PO, or using IAA.