A new Apple patent describes a sensor that, when attached to a wrist device, could detect the weight that you raise.
It is easy to assume that this technology could be adopted in the iWatch.
The filing details how a motion sensor could be used to keep track of arm movements and measure how many times you lift a weight during exercise.
The device would be able to records each repetition of the lifting of a weight, monitor intervals between these movements and compare them with past performance.
The actual transmitter is a small focused gadget that comes with an accelerometer, processor, Hall effect sensor and display.
The marketing of the iWatch is expected for October, according to a recent rumor.