Relationship between fatigue and fatigability on physical function: a review of the literature

Evaluating fatigue and fatigability’s association with physical function is of public health importance because among the older population almost 38.7% report one or more disabilities. Fatigue is also one of the most commonly reported reasons (65.5 episodes per 100 person-months) for restricted activity among community-dwelling older adults. Past research has only examined the relationship between fatigue and physical function, generally showing positive associations. However, fatigability may be a more useful concept when examining whether fatigue can predict physical function because it classifies fatigue in relation to a specific activity of fixed intensity making it a more objective measurement. Measuring perceived fatigability in place of physical activity may be a cost effective and less time consuming option when studying decline in physical function in older adults. Reducing fatigability and increasing physical activity can also potentially delay older adults entering the disablement pathway and improve their quality of life. A literature review highlighting major studies in the field of fatigue and fatigability may shed light on the gap in literature concerning the effects of fatigue on adverse health outcomes. This work is of public health importance as the symptom of fatigue is highly prevalent in older adult populations and if let unaccounted for can result in disability and worsened quality of life