“…Although physical activity is widely recognised as being beneficial to health, attempts to relate the effects of exercise to changes in platelet aggregation and functions have produced conflicting results. For example, some studies have reported that strenuous exercise results in increased platelet aggregation in response to adenosine diphosphate (ADP),f77-85] collagen [71,78,80,841 and adrenaline,f 74 1 Similarly, maximal cycling exerciseI76, 83,85] and maximal treadmill running! ?I] resulted in a significant activation of platelets as manifested by an increased sensitivity to ADPinduced aggregation, Radioimmunoassays of the plasma levels of ~-TG and platelet factor 4; plateletspecific proteins liberated from a-granules during activation, have been used as markers to assess the degree of platelet activation,186,87] Todd et al,l88] demonstrated a significant increase in platelet aggregability as reflected by an increase in plasma level of ~-TG in elderly men after treadmill exercise at 70 to 75% V02max, Other studies showed that strenuous exercise causes an increase in plasma level of ~_TGI16,18,66,76,81 ,84,[89][90][91][92][93] and platelet factor 4, [76,89,[93][94][95] Additional markers pertinent to platelet activation such as a-granule membrane protein [91] and thromboxane (TX) B2 were also increased after exercise,l88, 91,92] It has been suggested that exercise-induced activation of platelets might be linked with anaerobic metabolism for energy production during exercise.…”