An exercise data collection system and method of collection of data concerning the performance of weightlifters and the like which can be retrofitted for use with a power rack or half rack used by weightlifters and detached after use or alternatively set up in a freestanding arrangement, such as for use on a platform, in which by emitted electromagnetic radiation coupled detectors the movements of a barbell past such emitters is detected by the reflected emission and the speed of passage calculated by determining the interval between reflection of the detector beams between adjacent detectors, the height of such reflection beam being related to the portion of the musculature of the weightlifter that is undergoing extension or retraction during exercise.