From Today:
Are you neglecting your “second heart?” Sitting for hours at work or at home inactivates a critical part of the body that helps keep blood circulating properly.
The calf muscles are your “second heart,” squeezing veins in the lower legs to help return deoxygenated blood from the feet back up towards the chest, the Cleveland Clinic notes. But a sedentary lifestyle interrupts this process, which can cause blood to pool in the legs, leading to health consequences.