Described herein are apparatuses and methods for power adjustments of user measurement device. In one apparatus, a processing element is coupled to a first sensor interface and a second sensor interface. The processing element measures a physiological measurement via the first sensor interface and measures an amount of activity of the apparatus via the second sensor interface. The processing element performs a power adjustment activity in view of the amount of activity. For example, the power adjustment activity may be to perform any one or more of the following: adjust a number of different physiological measurements to take； adjusting a frequency of taking physiological measurements； turning off one or more systems； adjusting a type, frequency, data rate, number of channels and/or power at which to communicate data.
