The contraction of muscles with physical activity occurs after they receive a signal from the brain. If the signal does not come in, the muscles do not contract. The brain controls physical activity with the help of signals sent to the muscles. If more intensive physical work is required, the brain activates more fibers by changing the signal to the muscles. If the level of the load decreases, then this is controlled by the brain using a signal that activates a small amount of muscle fibers.
You must log in or register a new account in order to contact the publisher