title: Fatigability as a function of physical activity energy expenditure in older adults.
abstract: Increased fatigue is a predictor of morbidity and mortality in older adults. Fatigability defines a change in performance or self-reported fatigue in response to physical activity (PA). However, the relationship of fatigability to PA-related energy expenditure (PAEE) is unknown. Changes in performance, fatigue, and energy expenditure were measured simultaneously in 17 adults (11 females, 74-94 years old) performing eight standardized PA tasks with various energy expenditure requirements in a whole-room indirect calorimeter. Change in performance was objectively measured using a PA movement monitor and change in fatigue was self-reported on a seven-point scale for each task. Performance and perceived fatigability severity scores were calculated as a ratio of change in performance and fatigue, respectively, and PAEE. We found that change in both objective performance and self-reported fatigue were associated with energy expenditure (Spearman rho = -0.72 and -0.68, respectively, p < 0.001) on a task requiring relatively high level of energy expenditure. The performance and perceived fatigability severity scores were significantly correlated (rho = 0.77, p < 0.001) on this task. In summary, results of this proof of concept pilot study show that both perceived and performance fatigability severity scores are related to PAEE-induced fatigue on a task requiring relatively high level of energy expenditure. We conclude that fatigability severity is a valid measure of PAEE-induced fatigue in older adults.
authors: Energy Balance Laboratory, Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, Vanderbilt University, 1161 21st Avenue South, Nashville, TN 37232, USA. maciej.buchowski@vanderbilt.edu
authors: Maciej S
authors: MS
authors: Buchowski
authors: Sandra F
authors: SF
authors: Simmons
authors: Lauren E
authors: LE
authors: Whitaker
authors: James
authors: J
authors: Powers
authors: Linda
authors: L
authors: Beuscher
authors: Leena
authors: L
authors: Choi
authors: T Alp
authors: TA
authors: Ikizler
authors: Kong
authors: K
authors: Chen
authors: John F
authors: JF
authors: Shnelle
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D002153:Calorimetry, Indirect; D004734:Energy Metabolism / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005221:Fatigue / Q000378:metabolism* / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D010865:Pilot Projects