Background: Resistance exercise induces thrombocytosis and increases platelet activation and function. These changes might be related to exercise variables including exercise intensity and type.
Objective: We compared the effects of traditional resistance exercise (TRE) and circuit resistance exercise (CRE) on cellular markers of platelet activation and function.
Methods: In this crossover study ten healthy male (mean±SD: age, 25.6±2.4 years) subjects performed TRE encompassed 3 sets of 10 repetitions at 100% of 10-RM (10 repetition maximum) for 6 exercises, and CRE protocols included 3 sets of 10 repetitions at 100% of 10-RM for all 6 exercises consecutively, in two separate weeks. To measure platelet indices, PAC1, CD41a, CD42b and CD62P three blood samples were taken before, immediately after exercise, and after 30 min recovery.
Results: Lactate concentration, blood pressure, platelet count (PLT), and mean platelet volume (MPV) were significantly (p < 0.05) increased following both resistance exercise trials. Significant increases in PAC1, and CD62P; and significant reductions for CD42b and CD41a were detected following both REs (p < 0.05). However, changes in PAC1 and CD62P were significantly different between the two protocols (p < 0.05), with higher increases detected following CRE.
Conclusions: Acute RE increases platelet indices and platelet activation; and that CRE results in higher platelet activation than TRE, probably due to exercise-induced increases in shear stress.
Keywords: P-selectin; PAC1; Resistance exercise; platelet activation; weight training.