We present ARM (Adapting to Route-demand and Mobility), a control mechanism that allows any proactive routing protocol to dynamically adapt in a totally distributed manner to changes in node mobility and workload route-demands. Each node independently maintains a {\it mobility metric} indicating how fast its neighborhood is currently changing, and a {\it route-demand metric} indicating which destinations are currently involved in data forwarding. Control functions use these metrics to dynamically adjust the period and the content of routing updates. We apply ARM to the DSDV protocol, coming up with ARM-DSDV. For various mobility and workload scenarios, ARM-DSDV typically achieves the same data delivery
as DSDV with update period optimized for the scenario, while saving up to 60% in routing cost. Lower cost gives data traffic more available bandwidth. (Cross-referenced as UMIACS-TR-2001-08)