A shock absorbing bladder for use in the sole of an article of footwear is disclosed.
The bladder includes a plurality of inflated chambers at different pressure levels.
The bladder includes a first sealed chamber formed of a barrier material. The first
chamber contains a fluid at a first fluid pressure. A second sealed chamber also
forms part of the bladder. The second chamber is formed of a second barrier material
and contains an inflation fluid at a second fluid pressure that is greater than
said first fluid pressure. The second chamber is operatively coupled to the first
chamber so that the inflation fluid from the second chamber moves into the first
chamber to replenish fluid leaving the first chamber.