The number was originally a marketing stunt by Yamasa Corporation for the 1964 Olympics.
At the time, Yamasa Corporation introduced a portable pedometer under the name “Man-po-kei”. This Japanese term is made up of the words “man” for the number 10,000, “po” for “step” and “kei” for “measure”, which translates as “10,000-step meter”.
However, this number did not contain any well-founded, scientific research. Harvard professor Theodore Bestor discovered that the main focus was on finding a catchy name for the Yamasa device.