The advancement and proliferation of mobile devices and wearable sensors are changing the paradigm of personal wellness monitoring and chronic condition management. Mobile wellness monitoring is a promising service in the era of Internet of Things, however, there exist technical issues to be addressed. Energy efficiency is one of the basic essentials in the applications running on mobile devices of which power source is a limited capacity of battery. This study investigates techniques that focus on reducing energy consumption in mobile wellness monitoring applications. We divide the monitoring system into three levels (i.e., application level, sensor level, and gateway level) and explore the energy saving methods at each level.