Strength training may matter to the brain partly because muscle is an endocrine organ

Strength training may matter to the brain partly because muscle is an endocrine organ

Skeletal muscle isn't merely machinery that pulls on bones.

Contracting muscle releases signaling molecules often grouped under the term myokines.

Some participate in:

metabolism,
inflammation,
vascular function,
and communication between muscle and other tissues.

That creates an important shift in how to think about resistance exercise:

Muscle isn't only an outcome of exercise; muscle is part of the biological system through which exercise produces effects elsewhere.

This does not mean every exciting mouse study about a particular myokine proves lifting weights prevents dementia.

That's exactly the mechanistic-overreach problem we've discussed before.

But it does mean the old picture—

muscle = force-generating tissue

—is incomplete.

A more accurate picture is:

muscle = force generator + glucose sink + amino-acid reservoir + signaling organ.

That makes preserving muscle through middle and older age biologically interesting for reasons far beyond appearance.