It depends on a physical workload type I believe. If the physical effort is highly intensive (like sprinting), then the lactic acid accumulation determines the limit. If the physical effort is less intensive (e.g. middle distance running), the cardiovascular system efficiency can be the limiting factor. For a long lasting and low intensity efforts, the central nervous system might determine the limit (together with electrolyte accumulation in blood and muscles). Parameters describing these "limiting systems" are the only ones to inherence about physical workload capacity of a person. I hope this will help!

Best regards!

I agree with Radoslaw!

First of all, you need to be more specific regarding to the physical activity (lifting weight, sprinting, stretching,...) and the variables that you want to study (resistance, strenght, flexibility,...). Then, based on these criteria, you may establish the parameters and conditions to perform the study. Also, you may classify individuals according to their height, weight, race, and/or gender...

Best!

I am agree with Mr Radoslaw and Mr Erick. The physical worload capacity of a person differ with individuals. But for conducting such study sample survey is carried out and out of those selected randomly will carry for HR and OCR. It is only standard procedure for physiological evaluation. You can go for subjective evaluation also similar to Borg's scale evaluation.

Dear Azhar, it depends on how you define a "capacity limit of a person for physical workload". Which experimental protocol will you use? in the case of weightlifting, pure and simple, you must watch for  weight lifter  athletes performances; otherwise in case of dinamical movement of weights the thinks will be more complicated and the kind of measurements to be done heavily will depend on what will be considered a limiting factor