The lifetime of wireless sensor network is crucial, since autonomous operation must be guaranteed over an extended period. As all the sensor data has to be forwarded to an observer via multihop routing, the traffic pattern is highly nonuniform, putting a high burden on the sensor nodes close to the observer. We propose and analyze four strategies that balance the energy consumption of the nodes to increase the lifetime of the network substantially. The analyses are based on a Rayleigh fading link model. An important result is that the energy benefits of routing over many short hops in fading environments are insignificant; especially for smaller path loss exponents, it is sensible to use fewer but longer hops.