3.13 Muscle Movement Matters to Metabolic Recovery and T2 Diabetes Prevention
We don’t spend much time thinking about of all the interconnectivity between our brain and body. But, our brains and muscles are in constant conversation with each other, sending electrochemical signals back and forth. It’s a fact that to sustain brain health we have to keep our muscles moving  and this is even more important as we age. Exercise can improve mitochondrial biogenesis (new cells) and mitophagy (flushing of dead or “old” cells) both in the brain and our muscles . Skeletal muscle is the type of muscle that allows us to move our body around and it’s one of the biggest organs in the human body. This muscle is also an endocrine tissue, which means it releases signaling molecules that travel to other parts of our body to tell them to do things . The protein molecules that transmit messages from the skeletal muscle to other tissues -including the brain – are called myokines .
Myokines are released into the bloodstream when our muscles contract, create new cells, or perform other metabolic activities. When they arrive at the brain, they regulate physiological and metabolic responses there, too . As a result, myokines have the ability to affect cognition, mood, and emotional behavior. Exercise stimulates what scientists call muscle-brain “cross talk,” and these myokine messengers help determine specific beneficial responses in the brain. These can include the formation of new neurons and increased synaptic plasticity, both of which boost learning and memory. In these ways, strong muscles are essential to healthy brain function .
Even moderate exercise can increase metabolism in brain regions important for learning and memory in older adults.  The brain responds to exercise in strikingly physical ways. The hippocampus, which we know plays a major role in learning and memory, shrinks in late adulthood increasing our risk for developing dementia . Exercise has been shown to increase the size of the hippocampus, even late in life, improving memory, processing speed, executive function; protecting against age-related loss and improving spatial memory .