Effects of acute exercise on bleeding time, bleeding amount and blood cell counts: a comparative study

Area of Science:

• Exercise Physiology
• Hemostasis Research
• Blood Cell Analysis

Background:

• Hemostasis is crucial for preventing excessive blood loss.
• The impact of acute strenuous exercise on hemostasis requires further investigation, particularly regarding sex differences.
• Previous studies indicate variations in bleeding times among different ethnic groups.

Purpose of the Study:

• To investigate the effects of acute strenuous exercise on hemostasis in men and women.
• To compare bleeding times and blood cell counts before and after exercise.
• To examine potential sex-based differences in the hemostatic response to exercise.

Main Methods:

• A study involving 25 men and 26 women who underwent maximal workload bicycle ergometer exercise.
• Measurement of bleeding time using the Simplate method.
• Determination of venous blood cell counts for platelets (Plt), erythrocytes (RBC), and leukocytes (WBC) at rest and post-exercise.

Main Results:

• Bleeding time was significantly reduced after exercise in both sexes (men: 8.3 to 6.5 min; women: 11.4 to 8.6 min, p < 0.001).
• Acute exercise augmented bleeding rate and amount in men, but not in women.
• Significant increases were observed in RBC, WBC, and Plt counts post-exercise (RBC: 5-7%, WBC: 42-59%, Plt: 16-17%).

Conclusions:

• Acute strenuous exercise effectively shortens bleeding time in both sexes.
• Exercise induces significant hemoconcentration, increasing RBC, WBC, and Plt counts.
• Sex-specific differences exist in the hemostatic response to acute strenuous exercise, particularly concerning bleeding rate and amount.