i think the more times you hit failure the better
if your going heavy and can only get 4, say if you fail at that 10-20 times or 10-20 sets id say thats pretty good
or even 20 reps in 10-20 sets
of course the goal is always infinite energy thus we always need to refine our diet constantly to see how random foods help us consider new heights ; such as thos tasty yogurt pretzels bean and chees buritos krispy kreme jelly doughnuts (no-heme iron)
also mixed nut combonations with raisons do the trick for mid day heavy 1000 calorie meal the ones that got pumkin seeds, sunflour seeds and raisons mixed in
