Evaluation of the effect of circadian rhythm on balance and passing performance in football

ABSTRACT Aim: It has been shown that physiological changes in the human body related to circadian rhythm affect some performance measurements in sports branches. In this study, the effect of circadian rhythm on dynamic balance levels and pass performance of soccer players was investigated. Methods: In this study was included 32 healthy volunteer athlet, playing in the Bodrum Municipality Bodrumspor Club, age of between 18-20 and with at least 5 years experience, examinating by Turkey Football Federation regarding medical condition. Anthropometric measurements of the athletes were performed. After body temperatures were measured at 10.00 and 16.00 hours, Y balance test and Loughborough pass test were performed, and pass times were recorded. SPSS18 program was used to analyze the results. The suitability of the variables to normal distribution was examined by Shapiro-Wilk test. Paired t-test was used for variables in the normal distribution and Wilcoxon Signed Ranks Test was used for the variables not in the normal distribution. Pearson Correlation Test was used for normal distribution and Spearman Correlation Test was used for non-normal distribution. P <0.05 was considered significant. Results: Body temperature increased significantly in the afternoon compared to the morning (p <0.0001). In the morning, the pass hit increased and the pass time was shorter (p <0.0001 for both variables). The balance did not change in the afternoon (p = 0.65 for the dominant foot, p = 0.29 for the nondominant foot). No significant correlation was found between balance and pass performance measurements. There was a positive correlation between body temperature and balance measurements (p = 0.044, r = 0.359 for the dominant foot; p = 0.032, r = 0.381 for the nondominant foot). Discussion: Body temperature, which is an indicator of circadian rhythm, increases in the afternoon compared to the afternoon; A low positive correlation was found between body temperature increase and balance. There was no increase in balance in the afternoon, but when the relationship of balance to body temperature was examined, body temperature increase may have a supportive effect on heart rate; At the same time, increased sympathetic nervous system activity in the afternoon can provide more blood and oxygen to the muscles. However, although the body temperature increased in the afternoon, no significant difference was found in the balance measurements. This result was associated with the presence of other factors affecting balance. It was thought that better pass performance in the afternoon measurements was related to the higher attention and perception of athletes in the early hours. Our results support increased pass performance in morning exercises, but balance performance is not excellent as body temperature is low in the early hours. In morning exercises, general active warm-up exercises can be recommended to increase balance with training load methods. Key words: Circadian rhythm; dynamic balance; Loughborough pass test