A groundbreaking biomechanical analysis by researchers A. Baudouin and D. Hawkins from the University of California, Davis, published in the British Journal of Sports Medicine, reveals the complex interplay of forces that determine performance in rowing. While this research focuses specifically on rowing, the fundamental principles of propulsion, drag, and power transfer apply equally to sprint kayaking and canoeing, making these insights valuable for all paddle sport athletes seeking to optimize their performance.
The Physics of Speed: Understanding Propulsion and Drag
At its core, success in any paddle sport comes down to a simple equation: generating enough propulsive force to overcome the drag forces acting against you. As the researchers explain, “blade force was found to be the only propulsive force to counter the drag forces, consisting of both air drag and hydrodynamic drag, acting on the system.” This principle applies whether you’re pulling an oar through the water in a racing shell, driving a kayak paddle through a sprint course, or powering a canoe toward the finish line.
The drag forces working against you are substantial and consist of two main components. Air drag, while only contributing about 10% of total resistance in rowing, still plays a role as you and your equipment move through the air. The remaining 90% comes from hydrodynamic drag - the resistance created as your boat moves through the water. This hydrodynamic drag is particularly significant because “skin drag contributes over 80% of the hydrodynamic drag on a racing shell,” meaning the surface friction between your hull and the water represents the largest single force you must overcome.
Figure 1 from the cited paper: Free body diagram of a shell-oar-rower system showing the four main forces acting on the system: gravitational, buoyant, drag, and propulsive forces.
What makes this understanding crucial for athletes is recognizing that drag forces increase approximately with the square of velocity. This means that small fluctuations in speed require disproportionately large increases in propulsive force to maintain average velocity. For kayakers and canoeists, this translates to the importance of maintaining consistent boat speed rather than alternating between periods of high and low velocity, even if the peak speeds might seem impressive.
Equipment and Technique: The Mechanical Advantage
The relationship between athlete and equipment forms a critical link in the performance chain. In rowing, “the oar acts as the link between the force generated by the rower and the blade force and transmits this force to the rowing shell through the oarlock.” For paddle sport athletes, your paddle serves a similar function, though without the mechanical advantage of a fulcrum point like the oarlock in rowing.
The blade’s interaction with water involves both lift and drag mechanisms, and the proportion of each varies throughout the stroke. During different phases of the rowing stroke, “lift is the main source of force on the blade, as the blade moves sideways relative to the shell” in some phases, while “the second phase relies mainly on drag to generate the blade force.” Understanding this concept helps explain why blade angle, entry technique, and stroke path matter so much in all paddle sports.
For equipment optimization, the research reveals that “maximising sustainable power requires a matching of the rigging setup and blade design to the rower’s joint torque-velocity characteristics.” While kayakers and canoeists don’t have adjustable rigging like rowers, they can optimize paddle length, blade size, and shaft characteristics to match their individual strength and biomechanical profiles. The key insight is that equipment should be tailored to enhance your natural force-generating capabilities rather than working against them.
Figure 2 from the cited paper: Free body diagram of oar forces in the horizontal plane, showing how forces are transmitted from the handle through the oarlock to the blade.
The concept of lever arms becomes particularly relevant here. In rowing, adjusting the inboard and outboard lengths of the oar changes the mechanical advantage and affects the relationship between handle speed and blade speed. For paddle sport athletes, while you can’t adjust your paddle mid-race, understanding how grip position and paddle length affect this relationship can inform equipment choices and technique refinements.
The Human Engine: Biomechanics and Force Generation
The athlete represents the biological system driving the entire performance equation. The research emphasizes that “the force developed at the hand is critical to the propulsive force developed at the blade” and depends fundamentally on the athlete’s ability to generate and transmit force through their body. This force generation follows a kinetic chain where “the rower generates the foot stretcher force directly and acts as the mechanical link between the foot stretcher force and the oar handle force.”
For paddle sport athletes, this translates to the importance of connecting your entire body to the paddle. The legs initiate force against the footrests, the torso transmits and amplifies this force through rotation, and the arms and shoulders complete the transfer to the paddle blade. Any weakness or disconnection in this chain reduces the overall propulsive force available.
The relationship between force and velocity becomes crucial for performance optimization. As the research demonstrates through torque-velocity profiles, “muscle force and joint moments depend on the velocity of movement” and “as the joint angular velocity increases, the muscle torque produced about the joint decreases for all effort levels.” This means there’s an optimal stroke rate for each athlete that maximizes power output while maintaining sustainability over race distance.
Figure 6 from the cited paper: Torque-angular velocity profiles and power-angular velocity profiles for the hip and knee, showing how muscle power varies with contraction speed at different effort levels.
The timing and coordination of force application throughout the stroke cycle significantly impacts efficiency. The research notes that “sequential loading of leg, back, and arms results in each segment being loaded appropriately as the segment velocities increase and peak segmental forces decrease.” For kayakers and canoeists, this reinforces the importance of proper stroke sequencing - initiating with the legs and core, then engaging the torso rotation, and finally completing with the arms.
Performance Optimization: Putting Science into Practice
The practical implications of this research extend beyond understanding individual biomechanics to optimizing overall performance strategy. One of the most significant findings relates to minimizing velocity fluctuations: “velocity fluctuations in either the shell or the rower require greater propulsive force to maintain a given average system velocity than if the velocity was kept constant.” This principle applies directly to all paddle sports, where maintaining consistent boat speed throughout the stroke cycle proves more efficient than alternating between high and low velocities.
For crew boats in rowing, the research highlights that “coordination and synchrony between rowers in a multiple rower shell affects overall system velocity.” This coordination principle extends to team events in kayaking and canoeing, where synchronization between paddlers can significantly impact boat speed and efficiency. The timing of force application and stroke rate matching becomes crucial for maximizing team performance.
The concept of matching athlete characteristics to optimal performance parameters provides another avenue for improvement. The research suggests that “there should be an ideal stroke rating and rigging setup to produce appropriate contraction velocities and muscular effort levels to displace the shell effectively.” For individual paddle sport athletes, this translates to finding your optimal stroke rate that balances power output with metabolic efficiency over your race distance.
Understanding force-time profiles offers additional opportunities for technique refinement. The researchers emphasize that “force-time profiles should be better understood to identify specific components of a rower’s biomechanics that can be modified to achieve greater force generation.” For paddle sport athletes, this means analyzing not just peak force output but the shape and timing of force application throughout each stroke cycle.
The research concludes that performance improvements can come through two primary mechanisms: “either increasing the propulsive impulse or decreasing the drag impulse applied to the system during a stroke cycle.” This framework provides a clear focus for training and technique development - you’re either working to generate more forward force or reduce the forces working against you. Both approaches require the integration of proper biomechanics, optimized equipment selection, and strategic race execution.
For athletes in rowing, kayaking, and canoeing, this research underscores that peak performance emerges from the sophisticated interaction between the biological system (the athlete) and the mechanical system (boat and paddle). Success requires not just physical strength and endurance, but a deep understanding of how force generation, equipment optimization, and technique refinement work together to maximize speed over water.
Baudouin, A., & Hawkins, D. (2002). A biomechanical review of factors affecting rowing performance. British Journal of Sports Medicine, 36(6), 396-402.