Influence of Circadian Rhythm on Some of Coagulant, Anti Coagulant and Cardio Respiratory Factors Fluctuations after a bout of Incremental Exercise

The purposes of present study was comparing maximal oxygen consumption (vo2 max), some of coagulant factors including fibrinogen, platelet، P-LCR، PDW, MPV, and anti coagulant factors including protein C as a result of one bout of incremental exercise during morning and afternoon. Subjects of this study included 15 sport man with at least 2 years experience of participation in sport activities (age: 19±1. 2 years, height: 172. 1±5. 2 cm, weight: 66. 8±7. 5 kg). Subjects were selected randomly from volunteer and eligible students. Measurements were performed during morning (8 am) and afternoon (6 pm). Exercise training included maximal incremental exercise test of Bruce. During morning and evening (2 days interval) blood samples were taken before exercise test, after half an hour resting, Bruce maximal exercise test on treadmill was performed and immediately after test the second blood samples were taken. Heart rate and VO2max were recorded at the end of exercise test. Results of this study indicated significant increasing of MPV, Protein C, and P-LCR in morning compared to afternoon and Platelet in afternoon compared to morning after exercise (P≤0. 05). VO2max, heart rate and fibrinogen indicated no significant difference in morning compared to afternoon (P>0. 05). In summary we can suggest that although exercise performance was not significantly different in morning and afternoon, regarding increasing some of anticoagulant in afternoon and coagulant factor in morning as a result of exercise, afternoon exercise is preferred than morning exercise