Abstract
Introduction It is generally known that cardiovascular, respiratory, and metabolic responses are significantly different between cycling and running when performed at the same overall metabolic rate. Although blood coagulation and fibrinolysis have been extensively studied and reviewed (El-Sayed et al. 2010), the effect of exercise modalities on blood coagulation is not known. Therefore the aim of the present study was to assess the effect of exercise modes (cycling versus running) at 70% VO2max on blood coagulation in adults. Methods: Venous blood samples were removed from ten adults before and immediately after two separate ergometer-specific exercise trials at approximately 70% VO2max (for 45-min) on a treadmill and stationary pike; respectively. Blood was assayed for lactate, haematocrit (Hct) and haemoglobin (Hb); while citrated plasma was analyzed for prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), factor VIII activity (VIIIa), fibrinogen (Fb). Results and Discussion: Cycling and running exercise induced similar activation of blood coagulation as reflected by a significant (P<0.05) shortening in APTT, and nearly 2.5 fold rise (P<0.05) in VIIIa. Although plasma fibrinogen increased significantly (P<0.05) following exercise trials, no significant interaction was found between exercise modality and plasma fibrinogen responses. Exercise was not associated with any demonstrable change (P>0.05) in TT or PT. The generated thrombin was inactivated by antithrombin III and therefore did lead to the formation of fibrin. Conclusions: This investigation demonstrates that ergometer-specific exercise trials performed at 70% VO2max are associated with similar activation of blood coagulation system and the increase in TAT complexes highlights the importance of antithrombin III in the control of fibrin formation in vivo during exercise. References: El-Sayed.MS, Ali N, Omar AS. (2010) Effects of posture and ergometer-specific exercise modality on plasma viscosity and plasma fibrinogen: The role of plasma volume changes Clinical Hemorheology and Microcirculation, 47:1-10.