Work done on Breathing Work is defined as the energy needed to move objects in the direction of the force. During respiration, there are forces that impart or oppose movement. These forces have been defined by Isaac Newton (16421727) and are summarised as follows. 

First Law 
"an object at rest or in uniform motion will remain at rest or in uniform motion unless some external force is applied to it." 

Second Law 
"when a body is acted upon by a constant force, the force required to change movement is directly proportional to the mass and rate to which the object is accelerated." That is, the greater the mass or the greater the acceleration of an object, the greater is applied force needed to initiate or accelerate the object to some state of continuous motion. This is stated as F = ma, where m = mass and a = acceleration (rate of change in velocity or rate of change in the volume flow rate). 

Third Law 
"to every action force there is an equal and opposite reaction force" 


