Systems and methods for estimating lifestyle metrics with a wearable electronic device are disclosed herein. One disclosed system may include the wearable electronic device comprising a processor and a sensor system providing inputs to the processor. The sensor system may include a high power sensor and a low power sensor. The processor may operate in a high power mode in which both sensors are operational and a low power mode in which the high power sensor is not operational. In the high power mode, the processor may compute a lifestyle metric about a user for a first time period based on first data from the high power sensor. In the low power mode, the processor may compute the lifestyle metric for a second time period based on second data from the low power sensor and the first data and/or a derivative of the first data.