Data-collecting exercise device

An exercise device comprises a rigid rod having a first and second ends, a plurality of light sources arranged in a row along at least a portion of an axis extending between the first and second ends of the rigid rod, at least one load sensor for detecting an applied longitudinal force, and a processor coupled to the at least one load sensor and to the plurality of light sources. The processor is configured to execute machine-executable instructions that cause the processor to obtain a signal indicating a magnitude of the applied longitudinal force, and cause a subset of the plurality of light sources to emit light. A ratio of a number of light sources in the subset to a total number of the plurality of light sources represents the magnitude of the applied longitudinal force relative to a reference longitudinal force.