Abstract

This study aimed to determine the differences in muscle O-2 extraction capacity and physical fitness between physically active and sedentary schoolchildren. 19 students aged 10 to 14 years participated, categorized as physically active or inactive. In addition, a battery of basic physical condition and cardiovascular variables assessments was carried out. Physically active children demonstrated significantly greater efficiency in muscle O-2 extraction and resaturation during post-exercise recovery compared to sedentary counterparts (17.8 +/- 8.11s vs 26.1 +/- 8.54 s; p = 0.004; eta( 2) (p): 0.271). In the physical fitness tests there were only significant differences in the 30s Chair Stand Test (27.8 +/- 3.97 vs. 19.4 +/- 2.88 reps. P=< 0.001 eta 2 p: 0.614). These findings underscore the potential of regular physical activity to optimize peripheral vascular response and muscle oxygen utilization during post-exercise recovery in children.