Strenuous physical exercise induced an immediate enhancement in fibrinolytic activity (P<0.03) and a 2.2-3.2 fold rise in von Willebrand factor, suggesting increased susceptibility to thrombotic events.
Observational (n=7)
p-value: p=<0.03
Seven healthy male volunteers were subjected to exercise of short (STR; 1.7 km), middle (MTR; 4.8 km) and long (LTR; 10.5 km) term runs at a speed close to maximal capacity. Blood samples were drawn before, immediately after exercise and at intervals over the next 10 h. FVIIIR:Ag (von Willebrand factor) rose 2.2-3.2 fold and persisted at higher levels than baseline during the observation time. A spontaneous drop in FVII (p less than 0.03) was found immediately after STR (13.5 +/- 2.5%) and LTR (18.3 +/- 2.4%), whereas only a minor decrease (7.5 +/- 6.5%) occurred in MTR. The procoagulant activity of monocytes isolated from whole blood exposed to LPS showed a striking enhancement in STR and MTR. An immediate enhancement in fibrinolytic activity was found in all groups (p less than 0.03) assessed by increased plasma levels of t-PA and shortened whole blood clot lysis time (WBCLT). The transient shortening of WBCLT was succeeded by a tendency to prolongation of the lysis time. A 45-year old male differed markedly from the others by demonstrating an extreme and consistent prolongation of WBCLT. Thus, it has been speculated that strenuous exercise possibly makes a subject more susceptible to a thrombotic event.
Hansen et al. (1990) conducted an observational in Healthy (n=7). Strenuous physical exercise (short, middle, and long term runs) vs. Baseline (before exercise) was evaluated on Procoagulant and fibrinolytic activities (FVIIIR:Ag, FVII, t-PA, WBCLT) (p=<0.03). Strenuous physical exercise induced an immediate enhancement in fibrinolytic activity (P<0.03) and a 2.2-3.2 fold rise in von Willebrand factor, suggesting increased susceptibility to thrombotic events.