The invention is directed to rate control techniques for implantable pulse generator (IPG) systems. The techniques make use of a plurality of timing intervals that may replace conventional rate control and allow "double-pacing" pulses to be delivered in certain instances. For example, a second pulse, i.e., a "double-pacing" pulse, may delivered within a first time interval relative to delivery of the first pulse. However, the second pulse is not allowed once the first time interval has elapsed, if a second time interval has not also elapsed. If the second pulse is delivered during the first time interval, then the second time interval is restarted and another pulse cannot be delivered until the restarted second time interval has elapsed.