In our last post, Muscle Quality and the Neurological System: Part 1, we discussed the initial neurological changes that occur when we begin or restart our exercise program. The recruitment of dormant muscle fibers that have been efficiently put to rest by our nervous system are now being called back into action. Similar to when LeBron James recruited the best players to help him succeed, so too does our nervous system recruit more help via it’s “team” of increased muscle fibers.
However, the neurological impact of exercise goes beyond just the adaptive response of recruiting more muscle fibers. It includes the recruitment of potentially denser and greater energy producing fibers, more strength, and its corresponding effects (more muscle mass and increased bone density), as well as an enhanced hormonal response.
USE IT OR LOSE IT
There’s an interesting law of human physiology called the Law of Motor Unit Recruitment, and this is one of the significant points of differentiation with us at The Exercise Coach®. Most everyone knows or understands that as we age, we lose muscle mass (sarcopenia), and bone mineral density (osteoporosis). Our muscles are composed of various muscle fiber types and for purposes of discussion we will refer to the more common, slow and fast twitch fibers. As previously mentioned, if we don’t use these motor units (a motor unit consists of the motor neuron and all of the muscle fibers that it connects to or innervates), they become dormant, decline, or even die. The loss of muscle fibers is preceded by the loss of motor neurons. Since our fast twitch muscle fibers are bigger, more powerful, comprise the greatest percent of muscle mass in our body, and are also the most metabolically expensive, they are the first switches to be shut off. So as we age and lose muscle mass, a great percentage of it is our fast twitch fibers, and this reversal is the key to revitalization.
ACTIVATING AND RECRUITING MUSCLE FIBERS
In order to tap into and reawaken this metabolically active, fat-burning, energy producing tissue, we must sequentially and thoroughly fatigue our muscles. The Law of Motor Unit recruitment states that in order to fatigue and generate growth in our fast twitch muscles we first must fatigue our slow twitch muscle fibers. This critical element of exercise allows our Certified Exercise Coaches to find the Right Intensity of work to induce the proper amount of fatigue in your body. This forces the recruitment of these fast twitch muscle fibers. And, it all begins with reactivating motor neurons. Low intensity or aerobic workdoes NOT and has NOT been shown to have any significant effect on these muscle fibers, and is why simply being active or walking is not a significant enough stimulus to force meaningful adaptations to occur. (Roubenoff, R. 2001. “Origins and Clinical Relevance of Sarcopenia.” Canadian Journal of Applied Physiology 26(1):78-89.).
So, by creating a physically demanding event, (an Exercise Coach® session), our nervous system is forced to call upon reinforcements (see Part 1). Those reinforcements are the precious, metabolically active, yet dormant, tissue known as muscle. This neurological process is not unique to the muscular system, but the common denominator in this process is the physically demanding event! Once we have placed sufficient demand on our muscles, our body and brain are forced to no longer neglect these dormant nerve endings and bring back online thousands of untapped muscle fibers. This then increases our strength, as well as greater tension, leading to better bone growth stimulation, more glycogen depletion, improved insulin sensitivity, more lactate, and greater endocrine response. We will delve into these in greater detail in the coming weeks. As you would expect, the neurological system is the key first domino that sets off the chain reaction inducing all of these benefits to occur.
Check out this video of a client on our leg press as studio owner Amanda Coe explains the effects of our workout on Muscle Quality:
THE FUEL FOR MUSCULAR GROWTH AND IMPROVEMENT
One of the key elements in both the loss of muscle mass, and our body’s ability to re-generate the awakening and growth of muscle tissue, is nutrition, and specifically protein synthesis. To give our body the necessary raw elements for growth, research shows that protein is the crucial macronutrient to get the job done. One of the most important aspects of this is consuming enough energy (i.e. food). We are a people that have focused on dieting, specifically caloric restriction, as a means to improved health, but this is a crucial mental barrier we must overcome. Making sure we eat enough food, specifically the food that promotes stable blood sugar, decreases cellular inflammation, and improves gut integrity, is critical. These recommendations fall right in line with our nutrition recommendations and why our members have such phenomenal results.
The idea we have to accept the loss of muscle mass and its consequences as a fact of life doesn’t sit well with me. The fact that 60-70% of nursing homes are populated by those due to the loss of muscle mass is NOT okay with me! So, like LeBron, I want to set myself, my family and everyone who walks into an Exercise Coach® location up for their best chance at success. It starts by recruiting our own “super-friends” that are lying inside of us, patiently waiting to be called upon to help.
Read the rest of this series: