I will tell you this, I play in a flag football league in the fall. I was running dbol at the time at the beginning of the season. By the end of the 1st quarter, playing wide reciever the lower back pumps were so bad I could barely stand up, I had to go to the side line and lay flat on my back for about 30 mins until it started to feel just a little better. I had to bullshit everyone by telling them I pulled something. Horrible Horrible pain.