Paddling Force Profiles at Different Stroke Rates in Elite Sprint Kayaking.

In sprint kayaking the role that paddling technique plays in optimizing paddle forces and resultant kayak kinematics is still unclear. The aim of this study was to analyze the magnitude and shape of the paddle force-time curve at different stroke rates, and their implications for kayak performance. Ten elite kayak paddlers (5 males and 5 females) were analyzed while performing 2000-m on-water trials, at 4 different paces (60, 80, and 100 strokes per minute, and race pace). The paddle and kayak were instrumented with strain gauges and accelerometers, respectively. For both sexes, the force-time curves were characterized at training pace by having a bell shape and at race pace by a first small peak, followed by a small decrease in force and then followed by a main plateau. The force profile, represented by the mean force/peak force ratio, became more rectangular with increasing stroke rate (F[3,40] = 7.87, P < .01). To obtain a rectangular shape to maximize performance, kayak paddlers should seek a stronger water phase with a rapid increase in force immediately after blade entry, and a quick exit before the force dropping far below the maximum force. This pattern should be sought when training at race pace and in competition.