Introduction: The physiological characteristics in Olympic flat water kayaking races are well known today (1) and the latest studies are turning more to the kinematic (2) and neuromuscular parameters (3) of the activity. However, no studies have assessed the specificity of these characteristics in relation to the duration of the effort. The purpose of this study was to investigate modifications that occur in the paddling technique using a paddling ergometer during different maximal effort trials (40 seconds and 4 minutes). Methods: Nine experienced kayak paddlers who have competed at the French national level (female = 2, 18.6 ± 3.5 years) participated in this study. Athletes performed two maximum-effort trials of 40 seconds and 4 minutes, simulating an Olympic distance sprint (respectively 200m and 1000m). Physiological (Grip strength, blood lactate and muscle activity), biomechanical (power output, stroke rate) and kinematics data were recorded throughout the experiment. Results: The average maximum power output values were higher for 40 seconds over 4 minutes (p <0.01). Moreover maximum power output values were higher during the first 25% of the exercise compared to the 50%, 75%, 100% of the total exercise duration for both exercises (p <0.05). Muscular EMG activities were more important during the 40 sec exercises compared to the 4 min. Moreover the left triceps showed more activity changes over the two exercises. In addition the latissimus dorsi (during the 40s) and the right biceps (over 4 min) also show EMG activity changes. A grip strength loss (8.5% ± 4.67) was observed only after the 40 sec exercise for the right forearm. Post exercise blood lactate levels were significantly higher (p <0.01) for both types of maximal effort trials. Discussion: Our results show that anaerobic qualities are a very important factor for middle distance races such as a 1000 m in kayak. Muscle fatigue associated with the reduction of the maximum grip strength of the right hand after an exercise of 40 seconds could result from the different roles of the hands on the paddle. The orientation of the blades in water is ensured only with the right hand which requires continuous muscle contraction throughout the paddling while the left hand is contracted only during the left traction phases. Further work would be needed to confirm this hypothesis by comparing other kayakers using their left hand in the orientation of the blades in water.
© Copyright 2016 21st Annual Congress of the European College of Sport Science (ECSS), Vienna, 6. -9. July 2016. Veröffentlicht von University of Vienna. Alle Rechte vorbehalten.