International Journal of Sports Science 2014, 4(5): 165-172 DOI: 10.5923/j.sports.20140405.03 Muscle Synergy during Wingate Anaerobic Rowing Test of Collegiate Rowers and Untrained Subjects Shazlin Shaharudin 1,2,* , Damiano Zanotto 3 , Sunil Agrawal 3 1 Sport Science Unit, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Malaysia 2 Biomechanics and Movement Science Program, University of Delaware, 19716 DE, USA 3 Department of Mechanical Engineering, Columbia University, 10027 NY, USA Abstract The purpose of this study was to evaluate the muscle synergies during Wingate anaerobic rowing test of collegiate rowers and physically active individuals who were not specifically trained in rowing. As a power-endurance sport, high anaerobic capacity is one of the determinants of rowing performance. Due to the close link that exists between the state of energy supply and types of muscle fibers being recruited, the relationship of muscle synergies and rowing economy during an anaerobic dominant activity was investigated. Method: Ten subjects were recruited for both groups. Muscle synergies were extracted from 16 rowing specific muscles using Principal Component Analysis (PCA) with varimax rotation. An all out Wingate anaerobic rowing test was performed on Concept 2 sliding ergometer. Rowing performance, muscle synergies and physiological variables were analyzed. Results: Rowers showed better rowing performance in terms of peak power output, mean power output, distance covered, maximal oxygen consumption and energy expenditure compared to the untrained subjects. Three muscle synergies were extracted from both groups with some variability of timing coefficients and muscle weightings. A significant association was found between Synergy #1 and rowing economy, although there was no difference among the groups. Discussion: Expertise in rowing was related to the ability to adjust the sequence of synergies activation and the muscle weightings activation level during intense anaerobic burst. The rowers could apply the results from this study to improve rowing economy especially during the start of the rowing race, where anaerobic metabolism is predominant. Keywords Rowing, Muscle synergy, Anaerobic 1. Introduction A distinctive attribute of the rowing activity is the unique pattern of energy utilization [1]. The rowing races typically begin with a surge of intense anaerobic activity, followed by sustained maximum effort at 90-95% of aerobic capacity until the final sprint to the finish [2]. In fact, many studies have investigated the energy contributions [1], [3], [4], [5] during ergometer rowing. They noted that during rowing races, the rowers derived about 12% - 30% of anaerobic metabolism [4], [5], [6] and about 70% - 86% of aerobic metabolism [4], [5], [7] from the total energy metabolism. Huge contributions from both energy pathways entitle the rowing to be called a power endurance sport [8]. Specifically on anaerobic metabolism, it is capable to yield faster energy compared to aerobic metabolism but it lasted for a short period of time. Therefore, the anaerobic contribution is the key metabolism during the starting section of a rowing race which aimed to overcome the inertia of the * Corresponding author: shazlin@usm.my (Shazlin Shaharudin) Published online at http://journal.sapub.org/sports Copyright © 2014 Scientific & Academic Publishing. All Rights Reserved rowing shell [9]. Besides, in a 2000m indoor rowing test, 75.7% of the variance in rowing performance time was accounted for by the mean power during the Wingate test and only 12.1% of variance was related to VO 2 max [10]. Hence, the importance of great anaerobic capacity for rowers was further emphasized. Besides, rowing engages most of the principal muscle groups of the upper and lower body such that a larger fraction of total muscle mass is recruited when rowing compared to cycling (30 kg muscle mass compared to only 15 kg in a 70 kg male) [11]. The recruitment of greater muscle mass could potentially compromise muscle perfusion, particularly during heavy exercise [12] such as during all-out rowing, where a larger fraction of maximal cardiac output was utilized. Furthermore, a close relationship of the state of energy supply and types of muscle fibers being recruited [13] further complicate the performance factor. Hence, the importance of muscle synergy prevailed as the muscle coordination patterns could potentially limit the power output from a limb [14], and thus could be a determining factor of performance. Muscle synergy was defined as a specific and consistent spatiotemporal pattern of muscle activations that leads to similar joint trajectories [15] and has been proposed as a