The legs depend heavily on muscle movement to keep blood circulating. Every step, stretch, or shift in posture helps push blood back toward the heart. When movement stops, the system becomes sluggish.
Dr Varun Bansal, senior consultant in cardiothoracic and vascular surgery at Indraprastha Apollo Hospitals, explains the mechanism clearly, “Many people are unaware of the effects that long periods of sitting have on their cardiovascular health. While most people think about heart problems and the symptoms that accompany them, such as chest pains and breathlessness, the first signs of heart problems often begin in the smallest blood vessels, such as those in the legs.”
He adds that when people sit for long periods at desks, during long commutes, or while gaming, the leg muscles stop contracting. Without those contractions, blood does not circulate as efficiently.
This slowdown increases pressure on the microvasculature, the tiny blood vessels that feed tissues with oxygen and nutrients.