Patent ID: 8062182

Claim:
An exercise-monitoring system for use with an exercise device including a selectorized weight stack including a plurality of weights that are separated into a static-stack that is not lifted during an exercise and an active-stack that is lifted from the static-stack during the exercise, the exercise-monitoring system comprising: a static-stack light transmitter positioned to transmit a static-stack reference light to a static-stack reflector operatively connected to the static-stack, the static-stack reference light transmitted in a direction the static-stack reflector moves when the active-stack is lifted from the static-stack; a static-stack light receiver positioned to receive from the static-stack reflector an amount of reflected static-stack reference light that is proportional to a distance between the static-stack reflector and the static-stack light receiver; and a weight-determination module to output a weight indicator based on the amount of reflected static-stack reference light received by the static-stack light receiver.