Visualization is something commonly found in yogic and Ayurvedic techniques of breathing and meditation.  Here’s what science has to say on a physiological level:

• “…visualizing movement changes how our brain networks are organized, creating more connections among different regions. It stimulates brain regions involved in rehearsal of movement, such as the putamen located in the forebrain, priming the brain and body for action so that we move more effectively”
• ….studies show that imagining in the first person may activate muscles more powerfully than when we picture ourselves in the third person.
• this ability to trigger the motor cortex by imagining an action offers great promise in therapies for patients recovering from stroke and for athletes or dancers working to develop expertise in their craft. But as we get older, the motor cortex has to work harder to imagine actions, so exercising our visualization skills remains important throughout our lives. Mirror neurons, located in different regions of the brain but especially the brain’s motor system, may also play a role in generating movement.”
• Even though we treat our mind and bodies as two separate entities (brain vs. brawn; mind vs. matter), they are ultimately and intimately connected.
• the volunteers that performed imaginary exercise had stronger neuromuscular pathways and hence, stronger muscles.  The mentally-lazy volunteers had weaker neuromuscular pathways that were beginning to degrade.

Source: Scientific American

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