Determinants of kayak paddling

performanceApplication to paddling technique

Successful kayak paddling requires a powerful and skilful paddler with an appropriately designed kayak and blade to effectively maximize power to provide forward propulsion and minimize negative drag forces.

It is important to determinate the distance of competition. It is not the same 1000m and 5000m.

Introduction

The main objetive of the paddler’s power output is maintaining the kayak’s constant velocity.

Power=drag force x kayak velocity

Power required from the paddler is proportional to the kayak velocity cubed.

Introduction

Biomechanical effects on performance◦ During each stroke, the kayak has a fluctuating

velocity due to the dynamic movement of the paddler.

◦ During pull phase, the paddle is drawn through the water, creating a force greater than the drag forces (air and water resistance).

◦ Between strokes, the drag acts to slow the kayak down.

◦ Speed=propulsive effort – drag forces.

Kinetic data analysis

Drag◦ Aerodynamic and hydrodynamic◦ This forces decelerate the kayaks as it passes semi-submerged through

the water. ◦ The total drag force acting on the kayaker can be expressed by the

following equation: FTD=FHD + FAD

◦ FTD= total drag force, FHD=hydrodynamic drag force, FAD=aerodynamic drag force

◦ We can’t forget friction of surface drag, the pressure drag force and the wave drag force:

◦ FTD=FHDf + FHDp + FHDw

◦ FHDf=hydrodynamic friction drag force, FHDp=hydrodynamic pressure drag force, FHDw=hydrodynamic wave drag force.

Kinetic data analysis

Paddle force◦ The paddle acts to transmit the water-on-blade forces from the

paddler and hence from the kayak via the footbar and seat.

Kinetic data analysis

Fx=force in x-direction, Fy=force in y-direction, Fr=resultant force application

Forces at the footbar and seat◦ During kayak paddling, power is transferred to the kayak

through the application of forces against a footbar and seat.

Kinetic data analysis

Ffootbar, Fseat and Fpaddle are forces applied to the footbar, seat and paddle. mpaddler and apaddler are the mass and acceleration of the paddler.

mkayakd and akayak are the mass and Acceleration of the kayak.

Analysis of kinematic variables provides a description of the movement, without reference to the forces that cause the movement.

Paddler and paddle movement◦ Movements of the blade can be divided as: the catch, the

pull, the exit and the recovery.◦ The stroke began with the paddler entering the blade

forward and close to the longitudinal axis of the kayak.◦ The stroke side leg has to push against the footbar. ◦ The blade moves backwards and laterally until the instant

of exit phase. ◦ At the same time, stroke side knee and hip are extended to

help drive the hip backwards and produce torso rotation.

Kinematic data analysis

Kayak movement◦ During a stroke, a simultaneous shifting of body mass

occurs to keep the kayak laterally stable. ◦ While paddler attempts to extend the paddle forward, the

kayaker’s centre of gravity is moving faster than the boat. Then, the kayaker’s centre of gravity velocity is reduced and remains constant.

◦ Changes in body centre of gravity and kayak velocity cause unwanted movement that decreases kayak velocity and efficiency.

◦ Any acceleration by the large mass of the paddler (friction increasing) will result in a reaction in the boat, causing losing of speed.

Kinematic data analysis

Kendal, S. J., and Sanders, R. H. (1992). The technique of elite flatwater kayak paddlers using the wing paddle. International Journal of Sport Biomechanics, 8, 233–250.

Michael, J., Rooney, K., and Smith, R. (2008). The metabolic demands of kayaking: A review. Journal of Sports Science and Medicine, 7, 1–7.

Sanders, R. H., and Baker, J. D. (1998). Evolution of technique in flatwater kayaking. In V. Issurin (Ed.), Science and practice of canoe/kayak high-performance training (pp. 67–81). Tel Aviv: Elite Sport Department of Israel.

Sanders, R. H., and Kendal, S. J. (1992). A description of Olympic flatwater kayak stroke technique. Australian Journal of Science and Medicine in Sport, 24, 25–30.

References