Resistance training performed six times over two weeks increases the integrated rate of myofibrillar protein synthesis by approximately 26% in overweight older men during energy restriction.

When muscles are stretched and pulled during weightlifting, sensors in the muscle fibers detect the force and turn on signals that tell the cell to make more building blocks for muscle proteins. These signals boost the machinery that reads genetic instructions and assembles proteins, especially those that form the contractile parts of muscle. Even when calories are limited, this process speeds up protein production enough to rebuild muscle faster than it breaks down.