Citation

Krüger RL, Aboodarda SJ, Samozino P, Rice CL, Millet GY. Med. Sci. Sports Exerc. 2018; 50(10): 2132-2144.

Affiliation

Faculty of Kinesiology, University of Calgary, Calgary, CANADA.

Copyright

(Copyright © 2018, Lippincott Williams and Wilkins)

DOI

10.1249/MSS.0000000000001666

PMID

29787475

Abstract

PURPOSE: The assessment of power changes after fatiguing exercise provides important additional information about neuromuscular function compared to traditional isometric measurements, especially when exploring age-related changes in fatigability. Therefore, the aim of this review was to explore the effects of age on neuromuscular fatigue (NMF) when measured in isometric compared with dynamic contractions. The importance of central and peripheral mechanisms contributing to age-related NMF were discussed.

METHODS: Medline, EMBASE, Cochrane Central Register of Controlled Trials, and SPORT Discus databases were searched. The combination of terms related to the intervention (fatiguing exercise), population (old people) and outcomes (isometric force and power) were used. This meta-analysis was registered on PROSPERO (CRD42016048389).

RESULTS: Thirty-one studies were included. The meta-analyses revealed that force decrease was greater (there was more NMF) in young subjects than their older counterparts when fatigue was induced by isometric tasks (ES = 0.913, CI = 0.435 to 1.391, P < 0.001), but not when the fatiguing exercise was performed in dynamic mode (ES = 0.322, CI: -0.039 to 0.682, P = 0.08). Older individuals demonstrated a greater reduction in power after fatigue induced by either dynamic or isometric tasks (ES = -0.891, CI: -1.657 to -0.125, P = 0.023).

CONCLUSION: There is no difference in the isometric force loss between young and old people when fatigue is induced by dynamic tasks. However, maximal power is more decreased following fatigue tasks in older adults. Thus, the assessment of fatigue (isometric force vs. power) must be considered in identifying age-related NMF mechanisms.

Language: en