Dr. Andy Galpin

It is not only accepting information from the nervous system,

Also, from the hormones, endocrine system, things that are in your blood and everywhere else, it's also sending signals back out.

This includes things that are now called exokines.

So these are cytokines or, again, other information molecules excreted from muscle, in this case, in response specifically to exercise.

And their direct target is other organ systems in the body.

This would include the kidneys, liver, lungs, brain, and every other part of your system.

There are also other molecules that we'll discuss later, such as non-coding mRNAs, that are critical to your body understanding its overall status.

You see, really, the way that I think about it is skeletal muscle, given the fact that it occupies far more space in your body than anything else, is the primary key to physiology communication.

It is the biggest factor that is both receiving and extending information out to the rest of your body.

So when you don't have enough of it or it is compromised, you're going to see problems in every other area of your life.

To double down on that statement, if you were to look across the literature on both skeletal muscle mass as well as muscle quality, so think in this case,

muscle power, muscle strength, or something like that, you will see connections to basically every aspect of overall human health and performance.

And this is why if you were to look into the scientific literature on everything from sport performance to all-cause mortality, you'll see a strong tie to skeletal muscle quantity and quality.

So for example, skeletal muscle has been implicated in the regulation of numerous systems, which include, but are not limited to, all-cause morbidity and mortality,

cardiovascular health, cognitive health,

brain health, mood, inflammation, immunity, fertility, metabolic health, hormone health, bone health, and much more.

Another important thing to realize is that most of your metabolism in your body is actually occurring in your skeletal muscle.

In fact, because of this, around 85% or so of the heat you generate in your body is coming from skeletal muscle.

It's also the primary place in which you dispose of and regulate blood glucose.

which is important for both short-term performance as well as long-term health.