A couple of things further here:
In ASCE 7, Table 4-1, under "Office Buildings", the first two lines set the tone for design where it says "File and computer rooms shall be designed for heavier loads based on anticipated occupancy", but does not specify the design load. That is left up to the judgement of the engineer to be based upon the occupancy, distribution, and weight of the equipment.
Also, consider AISC 4.8.4, Special Occupancies, where it states that "Live loads of 100 psf OR LESS shall not be reduced in public assembly occupancies.
Also in the same Table 4-1, under "Assembly Areas and Theaters", is the recommendation for 150 psf for "Stage Floors". Considering how much acting that goes on in a locker room, you might want to consider this value too.
Mike McCann
MMC Engineering