Alright you guys I'm not an a cycle or nothing and I have done a bunch of research, This might be a very stupid question so if you feel like it is stupid don't answer it by me!

Alright lets say someboy is wants to run a cycle of Winny and D-bol or anything execept Test, Why is it important to have Test in the Background?

I have been asking myself this question and friends for a couple of weeks now!