"Huff~ Huff~"
Continuously exhaling warm breaths, the exhausted Uesugi Sakura stopped in his tracks.
The long-distance running had left his body feeling weary and sore, almost to the brink of collapse.
Cells need oxygen, and exercise accelerates oxygen consumption. Over time, if breathing can't supply enough oxygen to the cells, they switch to anaerobic respiration, which produces lactic acid, causing the body to feel sore.
Meanwhile, when oxygen supply in the bloodstream to the brain is insufficient, it causes blackouts and dizziness.
This intensity of running was already at the limits of physical endurance, even becoming more harmful than beneficial.
Yet today, Uesugi Sakura just felt like running like this, wanting to feel a bit tired.
Uesugi Sakura forced himself to overcome the dizziness and barely walked off the track, then bent over with his hands on his knees, greedily gulping down fresh air.
