# Energy dissipation and work of adherence force

Assume you are pushing a heavy item. But it's not moving. So there is no work, and there should also be no dissipation of energy $$P=F v=0$$, since the forces don't work. But we see that it does demand energy to exert a force. For example, you need a motor with a batterie, or if I push myself, I'll get tired ! So where does the dissipation take place ?