After 14 days of unilateral knee immobilization in healthy young men, mitochondrial protein VDAC2 is significantly downregulated, and multiple respiratory chain complex subunits are reduced, indicating disruption of mitochondrial membrane integrity and energy transfer capacity.

When a leg is kept still for two weeks, the muscle stops working hard, so the body reduces its energy-making factories called mitochondria. The outer membrane of these factories loses a key protein called VDAC2, which blocks the flow of energy molecules. Without this, the inner parts of the mitochondria break down, including the machines that make ATP. The cell also starts breaking down its own proteins to recycle materials, which removes even more energy-producing components. This causes the muscle to lose its ability to produce energy and shrink in size.