Sex differences in central and peripheral mechanisms of fatigue in cyclists
| Autor: | Malachy P. McHugh, Beth W. Glace, I J Kremenic |
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| Rok vydání: | 2012 |
| Předmět: |
Adult
Central Nervous System Male medicine.medical_specialty Time Factors Sports medicine Physiology Quadriceps strength Stimulation Quadriceps Muscle Magnetics Oxygen Consumption Sex Factors Time trial Physical medicine and rehabilitation Femoral nerve Peripheral nerve Physiology (medical) Internal medicine medicine Humans Orthopedics and Sports Medicine Muscle Strength Analysis of Variance business.industry Public Health Environmental and Occupational Health General Medicine Bicycling Peripheral Muscle Fatigue Physical Endurance Cardiology Female business Ventilatory threshold human activities Femoral Nerve Muscle Contraction |
| Zdroj: | European Journal of Applied Physiology. 113:1091-1098 |
| ISSN: | 1439-6327 1439-6319 |
| DOI: | 10.1007/s00421-012-2516-4 |
| Popis: | We examined peripheral versus central contributions to fatigue in men and women during prolonged cycling using a peripheral nerve magnetic stimulation-based technique. 11 men (41 ± 3 years) and 9 women (38 ± 2 years) cycled for 2 h at ventilatory threshold with 5, 1-min sprints interspersed, followed by a 3-km time trial. Quadriceps strength testing was performed isometrically in a semi-reclined position pre- and post-cycling: (1) MVC; (2) MVC with superimposed 3-s magnetic stimulation to measure central activation ratio (CAR), a measure of central fatigue; (3) peripheral magnetic stimulation (PMS) alone of the femoral nerve in a 4-s pulse train, a measure of peripheral fatigue. Data were analyzed with mixed model ANOVA. When adjusted for body mass, men and women had similar strength (p = 0.876), and changes in MVC with time were similar between sexes, declining 22 % in men and 16 % in women (p = 0.360). CAR was similar between sexes and decreased 15 % (effect of time, p0.001). Changes in PMS-elicited force were different between sexes: only men lost stimulated strength (6.30 to 5.21 vs. 5.48 to 5.53 N kg(-1), interaction p = 0.036). Results clearly demonstrate that quadriceps fatigue after2 h of cycling was of both central and peripheral origin in men but solely due to central mechanisms in women. |
| Databáze: | OpenAIRE |
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