My lifting buddy has done a couple DNP cycles. The first one was short and got up to 600mg. During this one, he was fatigued very easily and didn't do any major lifts(deads,squats).
The second one was a long mild cycle at 200mg. He is just finishing it now, and is lifting fine. He is on really low carbs, so he pops ECA for gym energy. He is still gaining strength from a mild test/primo/D-bol cycle that ended a couple months ago. He is still adding weight to his 5 rep max deadlift during the cycle. Considering his consistant progress while on, I would assume that his actual muscle loss is definately a non-issue.
Lifting on DNP is fine, depending how much you're taking.