Lifting weights as you age does more than just keep your muscles healthy.

The practice of weight lifting can improve the connections between our
muscles and nerves, and this strengthening is still possible in our later
years of life, according to new research on the subject.
Before the age of 40, we really begin to lose muscle mass, partly due to a
decline in muscle fibers brought on by the degeneration of motor neurons,
the cells in the brain and spinal cord that direct our bodies to move.