Introduction: Fatigue in tennis is multifactorial and influences the outcome of a match (Hornery et al., 2007). Indeed, fatigue can engender performance impairment, including mistimed strokes (velocity and precision), altered on-court movements (velocity, footwork and positioning to the ball) and incorrect tactical choices (Davey et al., 2002). The aim of this present study was to investigate the effect of a fatiguing tennis intermittent exercise on the upper-limb muscle electromyographic (EMG) activation level, ball velocity, stroke accuracy and consistency. Methods: Height elite tennis players performed a fatiguing tennis exercise composed of 4 sets of 8 minutes maximal tennis hitting (serve and forehand). Before and after fatigue protocol, subjects performed isometric maximal voluntary contractions (IMVC) as well as forehand and serve skill tests. Heart rate, blood lactate concentration and rating of perceived exertion were monitored during the fatigue protocol. Force and EMG were recorded during IMVC for internal arm rotators, wrist flexors and wrist extensors. Ball velocity, stroke accuracy, error percentage of strokes and EMG of height upper-limb muscles were assessed during the skill tests. Results: Mean heart rate, blood lactate and perceived exertion values attained respectively 176±9 beats/min, 5.7±2.5 mmol/L and 17.5±0.5 after fatigue. Significant decreases in serve velocity (3.2%) and forehand accuracy (21.1%) were observed after the fatiguing intermittent exercise. Error percentage of both strokes tended also to decline (p=0.056). EMG activation level for pectoralis major (PM) and flexor carpi radialis (FCR) significantly decreased during serve and forehand drives. EMG level of extensor carpi radialis activity decreased only during forehand drives. Force (-14%) and PM EMG amplitude declined during IMVC after fatigue. EMG activity for FCR was significantly lower in post-IMVC than in pre-IMVC while force stayed unchanged. Discussion: This study demonstrates that a fatigue protocol can simulate physiological strain induces by intense rallies and that generates significant performance decrease during serve and forehand drives. Velocity and accuracy losses were accompanied by a significant EMG decrease observed during tennis strokes and IMVC for PM and FCR principally. As discussed by Welsh (2002), fatigue seems to be associated with a decrement in central control. Thus players have to decrease velocity in order to maintain a high degree of accuracy in serve whereas during forehand the preservation of velocity appeared to be detrimental on stroke accuracy.
© Copyright 2012 17th Annual Congress of the European College of Sport Science (ECSS), Bruges, 4. -7. July 2012. Julkaistu Tekijä Vrije Universiteit Brussel. Kaikki oikeudet pidätetään. / Kääntänyt https://www.DeepL.com/Translator