Physical activity significantly influences blood composition, increasing blood volume, hemoglobin levels, and red blood cells (RBCs). Studies by Astrand and Rodahl confirm that trained individuals have greater blood and red cell volume than untrained individuals. While hemoglobin is critical for oxygen transport, its effect on oxygen consumption beyond normal levels remains debatable. Most research has focused on RBCs and hemoglobin due to their role in endurance and oxygen transport. However, white blood cells (WBCs) are also crucial for athletes, as they help resist diseases that could affect performance during competitive seasons.


Blood plays a vital role in maintaining the body’s internal environment, serving as a medium for transporting nutrients, waste, and oxygen. Regular physical activity enhances blood volume, which is approximately 5 liters in females and 6 liters in males, constituting 8% of body weight.



This research highlights the importance of periodic medical examinations for Libyan students, emphasizing that irregularities in blood variables can affect both health and academic performance. An experimental study was conducted on 20 Libyan students aged 25-30 in Serbia, divided into two groups: 10 physically active and 10 inactive.


Samples were collected before breakfast over three months, and key blood variables (sugar, triglycerides, cholesterol, RBCs, and hemoglobin) were analyzed.



Results showed significant differences between the two groups. Physically active students exhibited normal sugar levels, lower triglycerides, and cholesterol, along with higher hemoglobin and RBC counts compared to inactive students. These findings suggest that physical activity positively impacts blood variables, reducing risks associated with sedentary lifestyles, such as elevated cholesterol and triglycerides.

In conclusion, physical activity plays a crucial role in maintaining optimal blood health, highlighting the need for regular exercise and tailored health programs for students.



 Key Words: Physical activity, blood variables, Libyan students, Serbia, experimental study