Power-saving is a critical issue for almost all kinds of portable devices. In this paper, we consider the design of power-saving protocols for mobile ad hoc networks (MANETs) that allow mobile hosts to switch to low-power sleep mode. The MANETs being considered in this paper are characterized by unpredictable mobility and multi-hop communication. In MANET, we study how the node synchronization affects the performance in addition to the protocol complexity. We propose three synchronous power management protocols, namely Synchronous PFAI (SPFAI), Efficient SPFAI (ESPFAI), and Non-MTIM SPFAI (NSPFAI) protocols, which are directly applicable to IEEE 802.11-based MANETs.