Work load

The term workload can refer to a number of different yet related entities.

Workload is the amount of work an individual has to do. There is a distinction between the actual amount of work and the individual's perception of the workload. Workload can also be classified as quantitative (the amount of work to be done) or qualitative (the difficulty of the work).

The assessment of operator workload has a vital impact on the design of new human-machine systems. By evaluating operator workload during the design of a new system, or iteration of an existing system, problems such as workload bottlenecks and overload can be identified. As the human operator is a central part of a human-machine system, the correction of these problems is necessary for the operation of safe and efficient systems.

An operating budget may include estimates of the expected workload for a specific activity. Work loads can vary in many different situations, but the average workload is average.

Workload can also refer to the total energy output of a system, particularly of a person or animal performing a strenuous task over time. One particular application of this is weight lifting/weights training, where both anecotal evidence and scientific research has shown that it is the total "workload" that is important to muscle growth, as opposed to just the load, just the volume, or "time under tension". In these and related uses of the word, "workload" can be broken up into "work+load", referring to the work done with a given load. In terms of weights training, the "load" refers to the heaviness of the weight being lifted (20 kg is a greater load than 10 kg), and "work" refers to the volume, or total number of reps and sets done with that weight (20 reps is more work than 10 reps, but 2 sets of 10 reps is the same work as 1 set of 20 reps, its just that the human body cannot do 20reps of a heavy weight without a rest, so its best to think of 2x10 as being 20 reps, with a rest in the middle).

This theory was also used to determine horse power (hp), which was defined as the amount of work a horse could do with a given load over time. The wheel that the horse turned in Watt's original experiment put a certain load on the horse's muscles, and the horse could do a certain amount of work with this load in a minute. Provided the horse was a perfect machine, it would be capable of a constant maximum workload, so increasing the load by a given percentage would result in the possible work done decreasing by the same percentage, so that it would still equal "1 hp". Horses are, obviously, not perfect machines and over short time periods are capable of as much as 14 hp, and over long periods of exertion output an average of less than 1 hp.

...
Wikipedia