A medical device lead includes an insulated lead body including at least one electrode, a helically coiled conductor electrically coupled to the at least one electrode, and one or more polymer coils formed coaxially with the helically coiled conductor. The helically coiled conductor includes a plurality of turns having a conductive coil pitch and including one or more conductive filars each having a conductive filar diameter. The one or more polymer coils provide at least about 25 μN·m of torque transmitting capacity along a length of the medical device lead.