Purpose: In rowing, the athlete has to maximize power output and to minimize energy losses to processes unrelated to average shell velocity. The contribution of velocity efficiency (evelocity; the fraction of mechanical power not lost to velocity fluctuations) to rowing performance in relation to the contributions of maximum oxygen uptake (V˙O2max) and gross efficiency (egross) was investigated. Relationships between evelocity and movement execution were determined.
Methods: Twenty-two well-trained female rowers participated in two testing sessions. In the first session, they performed a 2000-m time trial on a modified rowing ergometer that allowed for power losses due to velocity fluctuations. The V˙O2max, the evelocity, and the amount of rower-induced impulse fluctuations (RIIF) due to horizontal handle and foot stretcher forces were determined in a steady state part of the time trial. RIIF was used as a measure of movement execution. In the second session, egross was determined at submaximal intensity.
Results: As expected, V˙O2max accounted for the major part of explained variance in the 2000-m time (53%, P < 0.001). Velocity efficiency accounted for a further 14%, egross for 11% (P < 0.05). Negative correlations were found between evelocity and RIIF values of several discreet intervals within a stroke cycle. The results suggest that optimal timing of forces applied to the ergometer will help minimizing power loss to velocity fluctuations.
Conclusions: This study indicates that a relationship exists between performance and evelocity. Furthermore, evelocity appears to be related to movement execution, in particular the timing of handle and foot stretcher forces.