| The Cosmic Treadmill first appeared in The Flash #125 in 1961
and appears in comics published by DC Comics.
The Cosmic Treadmill is a piece of exercise equipment with attitude.
Barry Allen, the Silver Age Flash discovered that
by vibrating his molecules at a particular speed, he could travel
in time or move into alternate dimensions. Finding that his control
of this ability was very imprecise, Allen constructed a treadmill that
allowed him greater control of the power.
When Allen ran on the Cosmic Treadmill, the device would begin
to vibrate at a particular frequency that would allow the Flash
to match his molecules vibrations to it. Once he had reached the
desired time or dimension, the Flash was able to maintain his
internal vibrations to match that time and thereby stay there until
he desired to leave when he would gradually reduce his internal vibrations
and return to his own time.
The Cosmic Treadmill was used during the Crisis on Infinite Earths
to transport a group of villains and heroes into the past to attempt
to foil the plans of the Anti-Monitor. It was also used by
Wally West, Superman, and his counterpart from Earth-2 to try and
breach the dimensions after the multiverse had been made whole. The
Cosmic Treadmill was seemingly destroyed, but was later repaired
and placed in a museum.
The Cosmic Treadmill has not been used much by the present bearer
of the mantle of the Flash Wally West. It is believed that
since West has a more direct connection to the Speed Force that
he has no need of the Cosmic Treadmill, instead using the Speed
Force to travel in time if needed. | 
