The brain is not a muscle, as tempting as the analogy may be.

More like a collection of footpaths that become more accessible with use.

Actually, it looks like it is.

See brain-derived neurotrophic factor, which will be elevated after many exercise, be them of mental origin or just walking.

Lifting weights also counts.

> See brain-derived neurotrophic factor, which will be elevated after many exercise, be them of mental origin or just walking.

Just because they share some biological commonalties (of course they do! How could it be otherwise?) doesn't make them meaningfully the same thing, any more than them both having lots of mitochondria does.