when i worked at a gym yrs ago it would only take me 20-25 minutes to do a bodypart,i worked at night when everybody was gone and heres what i did for example,id set up 7 chest exercises,like dumbell chest press,incline smith,hammer chest,hammer wide chest,dip station,decline dumbells,pec dec,then id go thru the whole 7 exercises with no rest and then rest 2 minutes once whole series was thru n repeat it 4 times,i know its seems quick 20-25 min n all but i swear to u my chest was on fire after that workout n i had a pump from hell.i did that on all my bodyparts and it really worked great.im a big believer in high intensity shorter workouts over medium intensity long marathon workouts.im not saying any against the longer training cause if it works for certain people thats great and they found their formula,im just saying from over 3 decades of training and trial and error ive found what works for me the best