Background and Aim: Early morning matches increase susceptibility to infection and inflammation in the athletes. The purpose of this study was to examine the effect of two weeks synchronized and non-synchronized training with testing on the serum levels of IL-17  and cortisol and strength performance in male athletes.

Material and Methods: We selected 14 male athletes randomly, and divided them into two similar groups. The morning group (7 =n, body weight =8/66± 68/85kg, age =1/73± 21 years, and training time: 9 AM) and evening group (7=n, body weight= 9/44 ± 69/42 kg, age =2/13± 19/71 years of age and training time: 18 PM). The training continued for two weeks (6 sessions in each week) according to a strength training program. To measure serum cortisol and IL-17 level, blood samples were taken three times, 24 h before the first training session as baseline, immediately after the tests at 9 am; and 48 h after the last training session. For the measurement of dependent variables, the participants consumed their breakfast 2 hours before the test. Data were analyzed using repeated measures, independent T-test, paired T-test and Analysis of Covariance (ANCOVA).

Results: The results showed that two weeks of adaptation (two weeks synchronization and non-synchronization of training with testing) resulted in a significant increase in the muscle strength (bench press performance) in the morning group (P <0.05), but in other strength movements, despite a significant increase in the maximal strength in all movements within each group, no significant changes were observed in the test of strength between the two groups (P> 0.05). Also, there were no significant differences between the two groups in regard to the serum levels of cortisol and IL-17 before and after the test (P>0.05).

Conclusion: It seems that two weeks synchronization or non-synchronization of training with testing had no significant effect on the levels of inflammatory markers but led to improved muscle strength (bench press) in male athletes.

Keywords: Biological clock, Circadian rhythm, Training time, Interleukin-17, Cortisol .

Received: Nov 23, 2015      Accepted: Jan 25, 2016