i used sd once and it was hell on earth, i'm not a competitive bencher but the back pumps were HORRIBLE, plus i was so lethargic it was crazy. and my joints were hurting so bad, i literally would sneeze and my elbows and shoulders would hurt for at least 5 minutes of aching pain. i stopped after 3 weeks, then had to keep dealing with the bs for another 3 weeks. i hated it.