Regular Resistance Training Enhances Fibrinolytic Potential but Does Not Affect Coagulation

Abstract

Elevated coagulation and/or lowered fibrinolytic activity increases the risk of a thrombotic event, which affects more than 2 million people each year. Resistance training (RT) produces various adaptations that are theorized to influence hemostasis, but research in this area is limited. Purpose This study aimed to identify effects of an 8-wk, whole-body RT program on coagulation and fibrinolysis. Methods Sixteen healthy women and men (23 ± 5 yr) completed an RT program three times per week for 8 wk. Exercises included 2-3 sets of 8-12 repetitions performed at approximately 60%-80% of a one repetition maximum. Strength, body composition, and body circumferences were assessed before and after training. Plasma samples were obtained before and after training, and analyzed for active tissue plasminogen activator (tPA activity), total tissue plasminogen activator (tPA antigen), active plasminogen activator inhibitor-1 (PAI-1 activity), total plasminogen activator inhibitor-1 (PAI-1 antigen), fibrinogen, and coagulation factors VII (FVII) and VIII (FVIII). Results Significant increases in lean mass, arm and thigh circumferences, maximal chest press (PRE: 57.8 ± 37.5 kg, POST: 73.3 ± 43.2 kg), and leg press (PRE: 189.5 ± 96.0 kg, POST: 256.7 ± 97.9 kg) were observed (P < 0.05 for all). PAI-1 activity (PRE: 20.3 ± 32.5 IU·mL-1, POST 9.5 ± 20.9 IU·mL-1) and PAI-1 antigen decreased (PRE: 10.2 ± 9.0 ng·dL-1, POST: 7.2 ± 5.7 ng·dL-1; both, P < 0.05). No change in tPA activity or tPA antigen occurred. Fibrinogen, FVII, and FVIII did not change after training. Conclusions Inhibition of fibrinolysis was decreased after training, and coagulation was unaffected. These results suggest that regular RT may beneficially influence the risk of a thrombotic event. More research is warranted to understand the mechanisms through which RT affects hemostasis.