The effect of arousal caused by spectators on process and outcome of volleyball serve skill

The Arousal is one of the psychological factors affecting athletes' performance. The most important theory of the relationship between arousal and performance is the inverted-U theory. Despite research in this area, more research is needed on the effects of arousal on cognitive and motor activities.

The purpose of the present research is to investigate the effect of arousal caused by spectators on the process and outcome of decision mking and volleyball serve performance skill.

The research method was quasi-experimental and the sampling method was also available randomly. The population of the study is the volleyball players of Iranian youth and student volleyball national team. A number of 29 players (Mean age=19.62 ± 2.243 years) participated in this research. At first, the players filled out the satisfaction form. At first participants performed decision making test.The decision making task of current study was performance of volleyball serve decision making under arousal conditions caused by spectators. Participants performed 25 decision making situations in baseline and spectators arousal conditions. The visual saccade and fixation data recorded by eye tracker system (Ergoneers Dikablis Eye Tracking System) simultaneously with decision making test performance. Data analyzed with paired-samples t-test. Then the participants performed the volleyball serve performance test (Brady volleyball skill test). The instrument used in the study was high frequency camera Sony cyber shot rx100 iv that used to record the players' performance for biomechanical analysis of serve performance. The tracker software was used to analyze the video performance of players' serve skills. The presence of spectators in the test environment was used to create arousal and also the measurement of athletes' heart rate was used to measure arousal. The subjects performed 10 services and their biomechanical factors included; distance to line, serve height, serve distance to line, landing distance to line and ball speed was recorded by camera. To ensure arousal, their heart rates were measured.

The results of the serve performance t-test showed that the arousal caused by the spectators has a significant effect on serve height (P=0.033). Also the result indicated that arousal caused by spectators affected the process and outcome of decision making.

Although the decision-making speed of the players increased under the circumstances of the arousal, their decision-making accuracy decreased. Given this, coaches need to provide good training tips in training to improve the decisions made by players. In addition to physical exercise, mental training and decision-making should also be done.