dont know for sure what you mean when you say " breath + pump " ... but i just woke up right now
take like a drumloop , and insert an comp ... do some serious gain reduction ...
so you defenatly hear the comps doing some ... like -10db or so .
then adjust the release to be as fast as possible ( full counterclockwise ) and it should " pump " like hell .
the attack now gives you the ability to control when the comp jumps in , so you either really kill f.ex the bass drum of a drumloop or you let it shine through if you slow down the attack ( clockwise ) . what ratio ? you´ll try yourself and listen what you like most .
clock& counterclockwise of course depend if the comps has some knobs working that way . there are some units working exactly the different way , like an 1176 etc .
lil bit confusing
good start for timing the comp to the material is using a delay chart ( if you know the tempo etc. ) .
but an real easy one .