Strengthen weak muscles and stretch shortened muscles.
Pecs is a shortened version of "pectorals" --the chest muscles above the "abs" (abdominal muscles).
the image looks shortened.
The muscles will atrophy (shrink) if not used.
you excersise
They contract
antizamboniism this is the scientific answer
The food will not be fully break down.
you will die
you exhale (:
contrast
What happens when a muscle shortens is that it is contracting. This is when the fibers of the muscles generate tension.