The source of the myth that you need 10,000 steps a day is a Japanese clockmaker that marketed a pedometer called Manpo-kei in 1965.

There's no more science to it than that. Read Marketwatch, here.

Believing hitting the 10,000 number might motivate you to push a little further or to do it every day. Sorry to spoil that for you. But did you actually believe that 10,000 was magical?

Do you have any beliefs involving numbers? Do you know the point at which it deserves to be called "arithomania"? It would be funny if your answer to that last question had a number in it? (It's arithmomania when you've got 10 beliefs about numbers.)

Arithomania is a mental disorder that may be seen as an expression of obsessive–compulsive disorder (OCD). Individuals suffering from this disorder have a strong need to count their actions or objects in their surroundings. Sufferers may for instance feel compelled to count the steps while ascending or descending a flight of stairs or to count the number of letters in words. They often feel it is necessary to perform an action a certain number of times to prevent alleged calamities. Other examples include counting tiles on the floor or ceiling, the number of lines on the highway, or simply the number of times one breathes or blinks, or touching things a certain number of times such as a door knob or a table....

I'm empty and aching and I don't know why/Counting the cars on the New Jersey Turnpike/They've all come to look for Arithomania....

IN THE COMMENTS: EDH brings up Malcolm Gladwell's 10,000 hour rule and "New Study Destroys Malcolm Gladwell's 10,000 Hour Rule." And Limited blogger said "I always thought 10,000 Maniacs was an unusually large number of maniacs." Here's the Wikipedia article "10,000" where you can make many discoveries about the meaning of 10,000. I'll just pick one, from Taoism:

The great Tao covers everything like a flood.
It flows to the left and to the right.
The ten thousand things depend upon it
and it denies none of them.
It accomplishes its task yet claims no reward.
It clothes and feeds the ten thousand things
yet it does not attempt to control them.
Therefore, it may be called "the little."
The ten thousand things return to it,
even though it does not control them.
Therefore, it may be called "the great."

So it is that the True Person does not wish to be great
and therefore becomes truly great.