Of all the 5/3/1 supplemental work, Boring But Big (BBB) is easily the most popular. BBB is not a good template for very new beginners or very advanced lifters. Beginners do not do well with multiple sets of ten reps, as they do not have the strength or technique to do them correctly. Very advanced lifters instinctively realize that BBB is not for them, and if they do attempt it, the know that they percentage of their supplemental work is very, very low. The reason for this is simple: 60% for an intermediate is not the same as 60% for an advanced lifter. Perform some easy conditioning on as many days as you wish provided you do so in a manner that allows recovery. Boring But Big will make you sore and take a lot out of you - so make sure you aren't adding more stuff into your training that inhibits your recovery. If you want to do harder conditioning work such as running hills, only do it two times per week. The goal is strength and size - so don't use this template if your goal is conditioning based. BBB is always a Leader template. After finishing either two or three cycles of BBB, you will change to an Anchor template. There are a number of different templates to choose from.