Is the brain like a muscle?

Yes the brain gains weight and speed with exercise. People with the need to learn or adapt to constantly changing challenges have the largest,and heavyest brains. Concert musicians who must constantly learn new works, truck drivers, Have the largest and heavyest brains. It takes about 5 years to get it up to full speed. And if not used 2 weeks to start losing weight and function. embly line workers, repetitious task, and police officers generally have the lightest brains. And slowest brain function. So the brain can be trained. Or abused to numbness.