Sentence:  Mr. Claude is a specialist in torso <WSD>development</WSD> and he has long favored the now famous Weider Push-Pull Super-Set technique in which one exercise of the Super-Set is a pressing or `` pushing '' movement which accents one sector of a muscle group in a specific way , followed by a `` pulling '' exercise which works the opposing sector of the same muscle group . 
Meaning of the word marked with <WSD> tags:  (biology) the process of an individual organism growing organically; a purely biological unfolding of events involved in an organism changing gradually from a simple to a more complex level