Platelet Function and Fibrinolytic Activity Following Distance Running

Abstract

6 long distance runners from the Danish marathon elite and 6 non-runners completed test runs of 28 and 12 km, respectively, Distance runners and non-runners showed the same responses in platelet function. We found a significant decrease in ADP induced platelet aggregability, a decreased serotonin release induced by ADP and collagen and an increase in platelet factor 4 immediately following the run. The antithrombin I11 levels remained constant. Euglobulin lysis time was shortened (by approximately 50 %) and the plasminogen levels significantly increased. The last 2 findings indicate an equal increase in fibrinolytic activity during distance running in both groups. While short term, strenuous exercise induces platelet hyperaggregation, long term distance running induces a state of exhaustion of platelet aggregation capacity.

Mean Platelet Volume (MPV) Predicts Middle Distance Running Performance

“…The significant increase of both platelet count (median increase, 17%; IQR, 10–34%) and MPV (median increase, 6%; IQR, 1–9%) recorded immediately after the half-marathon run substantially exceeded the inter-individual biological variation of these parameters (platelet count, 9.1%; MPV, 4.3%) [17], and is also consistent with the well established evidence that aerobic physical activity is effective to enhance circulating activated platelets, as well as platelet-platelet and platelet-leukocyte aggregates [18]–[22]. More specifically, it has been recently demonstrated that the hyperactive platelets generated during exercise are rapidly cleared by the spleen, which is also a dynamic reservoir of younger and larger platelets (i.e., the human spleen retains one-third of total body platelets, with MPV approximately 20% greater than that of circulating platelets) [23].…”

“…More specifically, it has been recently demonstrated that the hyperactive platelets generated during exercise are rapidly cleared by the spleen, which is also a dynamic reservoir of younger and larger platelets (i.e., the human spleen retains one-third of total body platelets, with MPV approximately 20% greater than that of circulating platelets) [23]. The younger platelets are then released into the circulation, thus explaining the significant increase of platelet count and MPV observed after endurance exercise in this and other previous studies [18]–[22]. Another putative mechanism that may contribute to increase the MPV has been reported by Hilberg et al [24], who observed that moderate exercise increased both platelet reactivity and platelet-leukocyte conjugate formation, which both contribute to increase the measured value of MPV.…”

“…Another putative mechanism that may contribute to increase the MPV has been reported by Hilberg et al [24], who observed that moderate exercise increased both platelet reactivity and platelet-leukocyte conjugate formation, which both contribute to increase the measured value of MPV. Regardless of the underlying mechanism(s), the significant increase of MPV recorded after exercise in this and other studies [18]–[22] has meaningful clinical implications, suggesting that the enhanced risk of cardiovascular events that is occasionally observed in athletes may be at least in part mediated by platelet hyper-reactivity [20]. Indeed, further studies are advisable to define whether an improvement of physical fitness is also accompanied with an increased MPV.…”

Biological Influence of Physical Exercise on Hemostasis

“…36 At variance with previous evidences, Knudsen et al observed a significant decrease in ADP-induced platelet aggregability, a decreased serotonin release induced by either ADP or collagen, and an increase in PF4 immediately after 12-to 28-km runs in both marathon elite and nonrunners. 46 A reduced platelet aggregation in response to adrenalin 35 and to epinephrine (-40%), ADP (-15%), collagen (-60%), and ristocetin (-10%) 36 was observed after 10-to 26.2-mile races. Consistent with this finding, Wang et al extended their previous study, 44 engaging sedentary healthy men in moderate (60% VO 2 max) rather than strenuous exercise on a bicycle ergometer, showing that moderate exercise was associated with lower extents of shear-induced platelet adhesion and aggregation, binding of von Willebrand factor (VWF) to platelets, glycoprotein IIb/IIIa activation, and P-selectin expression on platelet than those at rest.…”

“…[61][62][63] INFLUENCE OF PHYSICAL EXERCISE ON FIBRINOLYSIS Globally, available data on euglobulin lysis time (ELT) shows that this parameter is significantly shortened (by 50%) in elite athletes after a marathon run 34,64 and in both elite runners and nonrunners after 12-to 28-km runs. 46 Immediately after exhaustive stepping exercise, tissue plasminogen activator (t-PA) was significantly elevated in contrast with plasminogen activator inhibitor-1 (PAI-1), which decreased significantly until 1 hour after exercise in sedentary children. 38 Similar data were reported by Lin et al, who observed a significant increase in t-PA and a significant decrease in PAI-1 values after a standardized cycle ergometer test in active young men, which was followed by a sharp fall 2 hours thereafter.…”