Diurnal Variation on the Performance of Soccer-Specific Skills

The purpose of this study was to investigate diurnal variation in some specific skills performance and some physical fitness and physiological factors in soccer players. Twelve male soccer players (mean±SD; age 22.6±3 years; height 1.76±4.4 m; body mass 66.5±4.6 kg) participated in the study. Subjects performed some specific soccer skills and some physical fitness factors in one day. One test was carried out in the morning, between 7.00 and 9.00 and another one in the evening, between 19.00 and 21.00. A significant main effect of time of day was observed for oral temperature: the temperature in the evening was higher than morning (T= 2.83, P= 0.01). No significant time of day effect was found for hear rate (T= 1.72, P=0.11), systolic pressure (T=-0.67, P= 0.51) and diastolic pressure (T= 0.34, P= 73). A significant main effect of diurnal variation was found for sergeant jump (T= 4.98, P= 0.000), sit and reach (T= 4.1, P= 0.002), flexibility of right hip (T= 4.15, P= 0.002) and 20-m running (T=-4.27, P= 0.001): the values of these factors were better in the evening. A significant diurnal variation was found for dribbling (T= 3.55, P= 0.004), wall volley (T=2.83, P= 0.01), soccer chipping (T= 5.04, P=0.000) and Yeagley soccer test (T=-4.09, P= 0.02). No significant difference was found in penalty kick (P = 0.18). It can be concluded that there was a circadian rhythm in performance of soccer players.