Effort and fatigue
Fatigue is a normal part of everyday life, and is often a result of work, stress, or exercise or other activity. Effort required and fatigue experienced as a result of work can be physical, mental or both, depending on the type of work involved.
Mental and physical energy are separate biological functions and so are governed by very different underlying processes. Physical fatigue has very little impact on mental alertness, but mental fatigue can affect physical endurance as it affects the perception of exertion.
Someone’s physical fatigue can be affected by the amount of sleep they’ve had, the amount and intensity of exercise or work they’ve undertaken and their overall level of fitness. Physical signs of fatigue include sleepiness, yawning, heavy eyelids, loss of appetite, and in the case of chronic fatigue, it can also lead to digestive problems and more susceptibility to illness.
Mental fatigue can be caused by prolonged periods of demanding cognitive activity and can result in difficulty in focusing, slower reaction times, forgetfulness, poor recall, flawed logic and an increase in risk taking behaviour.
A worker who is experiencing fatigue might not be able to react as quickly in an emergency, to communicate important information to colleagues or even work productively.