The techniques of the disclosure describe example medical devices, systems, and methods for delivering stimulation therapy comprising a first set of a plurality of pulses having a first amplitude, and a second set of a plurality of pulses having a second amplitude greater than the first amplitude. The second amplitude is adjusted to an adjusted second amplitude based on second amplitude being less than or greater than activation threshold. The first amplitude is adjusted based on adjusted second amplitude, and therapy is delivered based at least one the adjusted first amplitude.
