Dr. Andy Galpin

So going back to our original point here, it's incredibly important that we do something to preserve our fast twitch fibers, because if we don't, we're going to lose them.

And that then becomes extraordinarily difficult to bring them back, especially once we've lost the fiber number.

Returning muscle function, so your strength is actually very manageable through aging, but increasing the amount of muscle fibers as we age is very difficult.

So once we lose them, they're basically gone for life.

Before we go any further, let's quickly go back and recap what we've talked about.

The importance of skeletal muscle extends far beyond sport performance or aesthetics.

In fact, it's important for a number of physiological factors across basically every organ system in your body.

We also know that skeletal muscle is uniquely responsive to changes in the external environment.

It is hyper-adaptable to things like changes in physical activity, nutrition, or various other lifestyle factors.

In fact, what I would call the superpower of skeletal muscle is its ability to respond and adapt both quickly as well as permanently.

We talked about how the muscles fibers themselves are multinucleated, which allows them that extended adaptability, as well as come in various forms, fast twitch and slow twitch fibers.

The fast twitch fibers being more difficult to preserve and probably require some sort of steady and consistent exposure to high force demands over the course of your life in order to maintain.

So what I'd like to do now is walk through the three I's, investigate, interpret, and intervene for both muscle quality and muscle quantity.

And I want to do them separately.

And that's because while there is a giant overlap between the two, they are independent factors.

Let me give you an example.

While there is a clear relationship between muscle size and muscle strength, such that generally bigger muscles are generally stronger, that's not necessarily always the case.

We can see a number of examples here.

Take any sport that is a weight class-based sport, wrestling, boxing, weightlifting, powerlifting.

Generally, the best of the best will increase their performance, in this case, say strength, as muscle size goes up.