Everyone has type I and type II muscle fibers. If your bulking up, you'll want to do a lot of sets of low reps. IE: 8 then 6 then 4 then 1 or 2, increasing the weight every time. Then go back to slightly lower weight then what you started with and push till you can't anymore, as many reps as you can. This way your building both types of muscle fiber and maximizing your workouts. Good luck!! If you truly are an Ecto, then you need to eat better, work out harder, and rest more then the other people who aren't. So to answer your question......Yes. Most definatly.