Quality delivers better results than quantity, no matter what the magazine says

Tighten muscle and lose fat now with these revolutionary new exercises.
With summer comes a hot list of innovative exercises that flood print and video (much the same for fall and winter by the way). That’s 10 new exercises you aren’t currently doing.
Oh well, change everything or add 10 more movements to your existing list (then ask for time off work because your workout just passed the three-hour mark).  
Just how many resistance exercises are too many?
As with most thing