Nice bit in Neurology here about exercise versus mental games in preserving mental function.
Unfortunately...no causation established.
But you have to keep moving.
If you're not moving you're dead.
Whether or not keeping on the move will allow you to remember where you put your keys is one thing.
But how about we narrow our view down a bit?
Way, way down.
Microscopic way down.
Ever seen an x-ray of a neck?
Did someone point out an area of degeneration?
Disc space is narrow or absent. Spurs. Messy looking anatomy.
How does this happen?
How about because you didn't keep moving.
See those spinal bones up there?
Between each one is (or in this case, was) a disc. A disc is a shock absorber between vertebrae. You know what happens when your car's shocks are shot. Now glance up at the radiograph and see what happens when your shocks are shot.
Our shock absorbers are always compared to a jelly donut. Gooey inside with hard tissue holding it in. The hard tissue is like a bias-ply tire. Basket weave strands of ligament make for a strong but pliable sack.
That's what your spine bounces around on.
Problem: Ligaments and tendons are slow healers and poor healers, relative to, say, muscle. Muscle gets plenty of blood (read: nutrients). Muscle is able to shed it's cellular waste easily.
Ligaments, not so much. No blood supply (i.e., avascular. Strange words are fun!), they receive nourishment and shed metabolic waste as bulk fluid flow across the endplates of the bones where they are attached.
In the morning the discs are nice and plump having been slowly swollen during rest.
Move around all day and they pump out fluid, becoming smaller.
And with that pumping action the disc rids itself of waste.
When we think of body movement it usually is of the gross kind, eg. walking.
But focusing down to disc level you can see that spinal motion is necessary for disc survival.
Focus down further to cell level with me and watch the disc die.
When spinal motion is lost from, for instance, a car wreck, the vertebrae above and below a disc (the motor unit) may become fixed.
Since the disc is dependant upon motion to remove waste, and the motion is lost, waste accumulates in the disc. Until motion is restored it can never properly or fully be cleansed of waste. The pH goes down within the disc (becomes acidic). Oxygen is lacking (hypoxia). Cells are destroyed (apoptosis. Another fun word!).
Poisoned and asphyxiated, the disc dies.
And you get x-rays like the one above.
I hope you have enjoyed our brief foray into desmology.
Get Up, Stand Up: Sitting for Too Long Doubles Diabetes Risk. Medscape. Oct 15, 2012.