ok in my last three leg day my lower back muscles (two muscles that are simulated in exercises like hyperextensions) get extremely tired and pumped! I can't stand in the end of training because they are extremely tired, there is no pain just pump and tiredness.

Today I decided to do hamstrings in a separate day, since doing hamstrings made my lowerback extremely tired and ruined rest of the session in last two sessions.

So i went with Leg Extensions, Squat, Leg Press, Hack Squat + Leg Extensions (with 3 seconds pause in the top) + Barbell Lunge

but again after doing Squat, my lower back got extremely tired, and I was only able to do 2 sets of the Lunges in the end, I had to lay down since I wasn't able to stand anymore!

So is it from dbol ? these pumps started from start of my dbol cycle and only on leg and back days ... I never had such a problem before since I got a quite powerfull lowerback muscles ... Is there anything I can do about it?