Muscle fatigue: from observations in humans to underlying mechanisms studied in intact single muscle fibres.
Prolonged dynamic exercise and sustained isometric contractions induce muscle fatigue, as manifested by decreased performance and a reduction in the maximum voluntary contraction force. Studies with non-invasive measurements in exercising humans show that mechanisms located beyond the sarcolemma are important in the fatigue process. In this review, we describe probable cellular mechanisms underlying fatigue-induced changes in excitation-contraction (E-C) coupling occurring in human muscle fibres during strenuous exercise. We use fatigue-induced changes observed in intact single muscle fibres, where force and cellular Ca(2+) handling can be directly measured, to explain changes in E-C coupling observed in human muscle during exercise.
Place
Nicolas
N
Institute of Movement Sciences and Sport Medicine, Faculté de Médecine, Université de Genève, Rue du conseil général 10, 1205, Genève, Switzerland. nicolas.place@unige.ch
Yamada
Takashi
T
Bruton
Joseph D
JD
Westerblad
Håkan
H
D056966:Excitation Contraction Coupling; D006801:Humans; D007537:Isometric Contraction; D018763:Muscle Fatigue; D018485:Muscle Fibers, Skeletal / Q000378:metabolism / Q000502:physiology*; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000294:innervation / Q000378:metabolism / Q000502:physiology*; D020127:Recovery of Function; D013997:Time Factors