Inactivity Changes the Brain
Studies say that exercise can remodel the brain by stimulating new brain cells and other positive changes. But now it appears that inactivity also remodels the brain in a negative way, says a new study.
Inactivity changes the shape of certain neurons that affect the brain and the heart.
Scientists thought that brain cells could not be altered after adolescence until neurological studies about 20 years ago established that the brain retains plasticity (the ability to be reshaped) throughout our lifetimes. Exercise is rather adept at remodeling the brain.
But now it appears that inactivity also alters the structure of the brain. The study on rats at Wayne State University demonstrated that exercise retained the proper shape of certain neurons in the rostral ventrolateral medulla that affect the sympathetic nervous system, while inactivity caused the neurons in sedentary rats to grow many more tentacles or branches. This means that the neurons in sedentary animals were more sensitive to stimuli and more apt to “zap scattershot messages” into the nervous system and overstimulate the sympathetic nervous system. This can potentially cause an increase in blood pressure and contributes to the development of heart disease.
This finding is important because we learn that inactivity increases the risk of heart disease. But the effect of inactivity on the brain is also significant.
“The time spent in physical exercise is not lost. The student who is constantly poring over his books, while he takes but little exercise in the open air, does himself an injury. A proportionate exercise of the various organs and faculties of the body is essential to the best work of each. When the brain is constantly taxed while the other organs are left inactive, there is a loss of physical and mental strength. The physical powers are robbed of their healthy tone, the mind loses its freshness and vigor, and a morbid excitability is the result.” Counsels to Parents, Teachers and Students, page 295