Effect of Stroke Rate on the Velocity/Time Curve of a Rowing Shell

Abstract

The 1976 U. S. Olympic eight oared crew was filmed (16 mm, 70 FPS) rowing six trials each at stroke rates of 37, 39, and 41 st/min. Shell instantaneous velocity was calculated and plotted for positions throughout the stroke cycle and a cubic spline curve fit to these data points. Time and percentage of total time for leg drive, upper body drive, transition, hands and upper body away, seat movement, and blades to water phases of the stroke cycle were determined. In addition, actual stroke rate, boat average velocity, and curve amplitude were calculated for each trial. Data was ranked by stroke rate and average velocity and a correlation matrix constructed to examine the relationships between variables. Minimum shell velocity occurred approximately 27% into the leg drive phase and maximum velocity was reached during the middle of the seat movement phase. Average shell velocity was found to be positively related to stroke rate (r = .66). Data analysis indicated that boat average velocity was increased by spending more total time exerting force with the legs, and was related to a rapid acceleration of power during the drive phase and a decreased time for recovery.