Influence of priming exercise on muscle deoxy[Hb + Mb] during ramp cycle exercise
| Autor: | Jan Bourgois, Thomas J. Barstow, Jan Boone, Jacques Bouckaert |
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| Rok vydání: | 2011 |
| Předmět: |
Adult
Male medicine.medical_specialty Time Factors Physiology Power frequency Incremental exercise Reference test Hemoglobins Young Adult Oxygen Consumption Physiology (medical) Internal medicine medicine Humans Orthopedics and Sports Medicine Cycle exercise Muscle fibre Muscle Skeletal Exercise Spectroscopy Near-Infrared Chemistry Electromyography Myoglobin Pulmonary Gas Exchange Osmolar Concentration Public Health Environmental and Occupational Health Architectural Accessibility General Medicine Surgery Bicycling Deoxy hb Endocrinology Leg exercise Priming Exercise Exercise Test |
| Zdroj: | European journal of applied physiology. 112(3) |
| ISSN: | 1439-6327 |
| Popis: | The aim of the present study was to gain better insight into the mechanisms underpinning the sigmoid pattern of deoxy[Hb + Mb] during incremental exercise by assessing the changes in the profile following prior high-intensity exercise. Ten physically active students performed two incremental ramp (25 W min(-1)) exercises (AL and LL, respectively) preceded on one occasion by incremental arm (10 W min(-1)) and on another occasion by incremental leg exercise (25 W min(-1)), which served as the reference test (RT). Deoxy[Hb + Mb] was measured by means of near-infrared spectroscopy and surface EMG was recorded at the Vastus Lateralis throughout the exercises. Deoxy[Hb + Mb], integrated EMG and Median Power Frequency (MdPF) were expressed as a function of work rate (W) and compared between the exercises. During RT and AL deoxy[Hb + Mb] followed a sigmoid increase as a function of work rate. However, during LL deoxy[Hb + Mb] increased immediately from the onset of the ramp exercise and thus no longer followed a sigmoid pattern. This different pattern in deoxy[Hb + Mb] was accompanied by a steeper slope of the iEMG/W-relationship below the GET (LL: 0.89 ± 0.11% W(-1); RT: 0.74 ± 0.08% W(-1); AL: 0.72 ± 0.10% W(-1)) and a more pronounced decrease in MdPF in LL (17.2 ± 4.5%) compared to RT (5.0 ± 2.1%) and AL (3.9 ± 3.2%). It was observed that the sigmoid pattern of deoxy[Hb + Mb] was disturbed when the ramp exercise was preceded by priming leg exercise. Since the differences in deoxy[Hb + Mb] were accompanied by differences in EMG it can be suggested that muscle fibre recruitment is an important underlying mechanism for the pattern of deoxy[Hb + Mb] during ramp exercise. |
| Databáze: | OpenAIRE |
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