Fourteen days of unilateral knee immobilization in healthy young men leads to consistent downregulation of proteins involved in mitochondrial organization and energy metabolism, including components of the electron transport chain and tricarboxylic acid cycle, resulting in impaired cellular energy production.

When a leg is kept still for two weeks, the muscle stops working hard, so the cell stops making as many energy-producing machines. This causes the mitochondria to shrink and produce less energy. At the same time, the cell starts breaking down its own proteins, including those needed for energy and muscle structure, leading to muscle loss.