New research suggests muscles respond to simple thoughts of exercise; simply imagining exercise can trick the muscles into delaying atrophy and even getting stronger. It's further proof that brain and body, which evolved together, are more intwined than separate.

To demonstrate the power of the brain, researchers at Ohio University wrapped a single wrist of two sets of study participants in a cast -- immobilizing their muscles for four weeks. One set was instructed to sit still and intensely imagine exercising for 11 minutes, five days a week. More than just casually daydream about going to the gym, participants were instructed to devote all of their mental energy towards imagining flexing their arm muscles.

The other set of study participants weren't given any specific instructions. At the end of the four weeks, the mental-exercisers were two times stronger than the others.

Researchers also used magnetic imaging to isolate the area of the brain responsible for the specific arm muscles. Participants that imagine exercise not only had stronger arms but also a stronger brain; their mental exercises created stronger neuromuscular pathways

"What our study suggests is that imagery exercises could be a valuable tool to prevent or slow muscles from becoming weaker when a health problem limits or restricts a person's mobility," study author Brian Clark, a professor of physiology and neuroscience at Ohio University Heritage College of Osteopathic Medicine, said in a press release.

"The most impactful finding, however, is not the direct clinical application but the support that this work provides for us to better understand the critical importance of the brain in regulating muscle strength," Clark added. "This information may fundamentally change how we think about muscle weakness in the elderly."

Previous studies have shown that mental exercise can actually make muscles stronger (as opposed to simply preventing or slowing atrophy), and that thinking about exercise activates the same areas of the brain as real exercise.

Of course, researchers aren't suggesting forgoing exercise; nothing works quite as well at encouraging both brain and body health as the the real thing.

The study was recently published in the Journal of Neurophysiology.