Human skeletal muscle responses vary with age and gender during fatigue due to incremental isometric exercise

• Published in: Journal of applied physiology (1985) 2002-11, Vol.93 (5), p.1813-1823
• Main Authors: Kent-Braun, J. A, Ng, A. V, Doyle, J. W, Towse, T. F
• Format: Article
• Language: English
• Subjects: Action Potentials; Adult; Age; Aged; Aged, 80 and over; Aging - physiology; Biological and medical sciences; Cross-Sectional Studies; Electric Stimulation; Electromyography; Energy Metabolism; Exercise; Exercise - physiology; Fatigue; Female; Fundamental and applied biological sciences. Psychology; Gender; Humans; Isometric Contraction - physiology; Magnetic Resonance Spectroscopy; Male; Metabolism; Muscle Fatigue - physiology; Muscle, Skeletal - physiology; Sex Characteristics; Spectrum analysis; Striated muscle. Tendons; Vertebrates: osteoarticular system, musculoskeletal system
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/japplphysiol.00091.2002

1  Department of Exercise Science, University of Massachusetts, Amherst, Massachusetts 01003; 2  Exercise Science Program, Marquette University, Milwaukee, Wisconsin 53201; and 3  Magnetic Resonance Unit, Department of Radiology, University of California, San Francisco, California 94121 The purpose of this study was to compare the magnitude and mechanisms of ankle dorsiflexor muscle fatigue in 20 young (33   ± 6 yr, mean ± SD) and 21 older (75 ± 6 yr) healthy men and women of similar physical activity status. Noninvasive measures of central and peripheral (neuromuscular junction, sarcolemma) muscle activation, muscle contractile function, and intramuscular energy metabolism were made before, during, and after incremental isometric exercise. Older subjects fatigued less than young ( P