Hi Dorothyrd! I'm not sure if I know exactly what you are asking but I'm going to assume you mean the STS legs and what to do about all the options offered. The true Mesocycle #3 program is all about strength....well, in a home environment, most people will not have squat racks and spotters to help assist them in the type of weights that you need to safely lift over your head to get into your squat position. If you do and you want the optimal results of Mesocycle #3, choose the squat rack routine.
But for those who don't have this access, we wanted to find the next best thing to get you there, and that is to put on a weight vest so that you don't need the spotter or squat rack to do the heavy squat (keeping in mind you still most likely will never be able to put up the weight you would with the squat rack/spotter option). But it will still provide you with excellent strength gains.
But as a third option, we provided a plyometric/strength training workout to help recruit fast twitch muscle fibers (those called upon for power and strength). While this certainly deviates from the original purpose of Meso #3, it certainly developes power and strength in its own right and therefore is included in Meso #3's strength program.
So now you have three ways to develope strength. I would pick one method and stick to it while doing STS in its entirety, but after that you can pick and choose as you see fit (no pun intended )
Thanks, I think you understood my question, because I was trying to figure out if all 3 options were to be used during meso3, or pick one the first time, and then the others are options to do at another time.