You may want to try supplementing with CoQ10.
Google on CoQ10 +statins or statin myopathy treatment
I've been using CoQ10 for several months now and when I call on the legs for some extra in a sprint to when climbing, they answer the call and respond. This was an effect I experienced after a couple of weeks.
I take a version of it called Ubiquinol.
http://www.swansonvitamins.com/SWU393/ItemDetail