Effect of Playing Surface Properties on Neuromuscular Fatigue in Tennis JEAN-BERNARD FABRE 1,2 , VINCENT MARTIN 3,4 , JULIEN GONDIN 1,5 , FRANÇOIS COTTIN 3 , and LAURENT GRELOT 1 1 ISM, CNRS, Aix-Marseille University, Marseille, FRANCE; 2 Research Department, ESP-Consulting, Aix-en-Provence, FRANCE; 3 UBIAE (INSERM U902), Faculty of Sport Sciences, Val d’Essonne University, Evry, FRANCE; 4 AME2P Laboratory, Clermont University, Blaise Pascal University, Clermont-Ferrand, FRANCE; and 5 CRMBM, CNRS, Aix-Marseille University, Marseille, FRANCE ABSTRACT FABRE, J.-B., V. MARTIN, J. GONDIN, F. COTTIN, and L. GRELOT. Effect of Playing Surface Properties on Neuromuscular Fatigue in Tennis. Med. Sci. Sports Exerc., Vol. 44, No. 11, pp. 2182–2189, 2012. Purpose: The aim of this study was to evaluate the effect of the playing surface properties on the development of neuromuscular fatigue in tennis. Methods: Ten subjects played randomly two tennis matches on hard court (HARD) and clay court (CLAY) for an effective playing duration of 45 min (i.e., corresponding approximately to a 3-h game). Before and after each match, the maximal voluntary contraction (MVC) force of the plantar flexors, the maxi- mal voluntary activation level, the maximal compound muscle action characteristic, and the EMG activity were determined on the soleus (SOL) and lateralis gastrocnemius (LG) muscles. Tetanic and single stimulations were also delivered to evaluate the presence of low-frequency fatigue and contractile impairment. Finally, reflex responses were evoked on the relaxed muscle (H-reflex) and during MVC (H-reflex and V-wave). Results: Statistical analysis did not reveal any significant difference between playing surfaces. MVC was similarly reduced after the game (HARD, j9.1% T 8.7%; CLAY, j4.3% T 19.9%) and was associated with alterations of the contractile properties of the plantar flexor muscles. The implication of central factors was less clear, as evidenced by the significant reduction (P G 0.05) of the H-reflex on the relaxed LG (HARD, j16.2% T 33.3%; CLAY, j23.9% T 54.0%) and SOL (HARD, j16.1% T 48.9%; CLAY, j34.9% T 35.9%) and the nonsignificant reduction of the activation level. In addition, the reflex responses evoked during MVC were not significantly modified by the exercise. Conclusion: These results suggest that the ground surface properties influence neither the extent nor the origin of neuromuscular fatigue in tennis. The moderate force decrement observed in the current study was mainly associated with peripheral fatigue. Key Words: VOLUNTARY ACTIVATION LEVEL, H-REFLEX, M-WAVE, V-WAVE, CENTRAL FATIGUE, PERIPHERAL FATIGUE F atigue is usually described as a time-dependent exercise- induced reduction in the maximal force generating ca- pacity of the muscle. This complex phenomenon is the result of the combination of many factors from the central (nervous) to the peripheral (muscular) level (11). It is well known that the extent and origins of neuromuscular fatigue differ according to the type of muscle contraction, the mus- cular group involved, the exercise duration/intensity, and the environmental conditions (7,30,36). Among the environmental conditions, the effect of the playing surface has received little attention in the literature. The unique characteristic of the tennis game is to propose confrontations on surfaces with different frictional and cush- ioning properties, which directly influence the ball rebound and the game speed (8). Two playing surfaces are recognized as radically different: The clay court (CLAY) is characterized by a slow game, a sleepy surface, and high bouncing balls. Conversely, the hard court (HARD) (GreenSet Ò , Barcelona, Spain) is a fast but rough surface with high frictional prop- erties, producing normal ball rebounds. As a consequence, tennis players adjust their game strategies to the surface they play on, so that both the duration of the rallies and the ef- fective playing time are longer on CLAY than on HARD (32). The aerobic metabolism is therefore more solicited on CLAY than on HARD (26,32). In addition, the frictional and cushioning properties of the surface also influence the inten- sity of ground impacts and thus the lower limb muscle con- tractions (18). Although CLAY surface limits ground impacts and diminishes the intensity of the braking (i.e., eccentric) phases because it allows sliding, HARD may expose the player to higher impact forces and intense eccentric contractions dur- ing the braking phases (12). Impacts and eccentric contractions have been shown to be responsible for the development of Address for correspondence: Jean-Bernard Fabre, Ph.D., ESP-Consulting, Les hauts de la Duranne, 505 avenue de Galile ´e, 13857 Aix-en-Provence, France; E-mail: jb.fabre@esp-consulting.fr. Submitted for publication November 2011. Accepted for publication May 2012. 0195-9131/12/4411-2182/0 MEDICINE & SCIENCE IN SPORTS & EXERCISE Ò Copyright Ó 2012 by the American College of Sports Medicine DOI: 10.1249/MSS.0b013e3182618cf9 2182 APPLIED SCIENCES Copyright © 2012 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.