Time of Day Effect on Repeated Sprint Ability, Aerobic Capacity, and Physiological Responses in Team-Sport Athletes

Abstract

The aim of this study was to examine the time of day effect on aerobic capacity, repeated sprint ability and physiological responses in team-sport athletes. Ten male athletes (age: 21.60 ± 1.42, height: 185.10 ± 7.30cm, body weight: 82.15 ± 4.88, % body fat: 12.98 ± 2.39) who regularly exercise and engage in team sports, participated in this study voluntarily. Athletes were subjected to Repeated Anaerobic Sprint Test and 20m Shuttle Run Test at three different times of the day in the morning (09.00-10.00), afternoon (12.00-13.00) and evening (16.00-17.00) at two-day intervals. As a result of Repeated Measures ANOVA, statistically significant differences were observed when comparing body temperature (F(2,18)=10.042, p=.001), vertical jump height (F(2,18)=9.216, p=.005), maximal power (F(2,18)=9.059, p=.002), mean power (F(2,18)=8.617, p=.002), minimum power (F(2,18)=7.120, p=.002), aerobic capacity (F(2,18)=6.967, p=.006), maximal heart rate F(2,18)=6.859, p=.006), and blood lactate levels after exercise tests (F(2,18)=6.041, p=.010) measured at morning, afternoon and evening time periods. According to Bonferroni test results; body temperature, vertical jump height, maximal power, aerobic capacity values were found to be statistically higher in the evening hours than the morning hours (p<0.05). Blood lactate level and maximal heart rate were increased significantly after tests in the evening (p<0.05). In this study, factors such as having a good sleep quality, body temperature and circadian type can be shown as reasons for the performance of the athletes to be good in the evening compared to the morning hours. In conclusion, while planning the athletic training programs, it is thought that it is important to perform training which include aerobic and anaerobic capacity, explosive power and jumping exercises in the evening hours because of the significant increases in performance of the athletes