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Denguezli M Ben Chiekh I Ben Saad H Zaouali-Ajina M Tabka Z Abdelkrim Z 《Journal of sports sciences》2008,26(12):1351-1359
The aim of this study was to determine whether endurance training in athletes induces airway inflammation and pulmonary function disorders. Respiratory pattern and function were analysed in ten healthy endurance runners at rest, during sub-maximal exercise, and during the recovery. Inflammatory cells and metabolites (histamine, interleukin-8, and leukotriene E(4)) were measured in sputum at rest and after exercise. The experiments were conducted on three different occasions (basic endurance training, pre-competitive and competitive periods). In spite of the absence of post-exercise spirometric changes and respiratory symptoms, airway cells counts and inflammatory markers changed significantly. At the beginning of the experiment, athletes' induced sputum showed an abundance of macrophages compared with neutrophils. We found a high percentage of neutrophils during the pre-competitive and competitive periods of the sport season (41% and 37%), a significant increase in macrophage counts during the pre-competitive period (51%), and a significant rise in total cells, interleukin-8, leukotriene E(4), and histamine during the competitive period. In conclusion, one year's training increased markers of inflammation in the airways of endurance runners without symptoms or changes in pulmonary function, suggesting that airway inflammation is of insufficient magnitude to markedly impact lung function in healthy athletes. 相似文献
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The aim of this study was to examine the time-course of and the relationships between muscle oxygenation, blood volume and myoelectrical manifestations during isometric exercise in children. Twelve healthy children aged 12.5 +/- 1.2 years (mean +/- s) performed an isometric knee extension at 50% of their maximal voluntary contraction (MVC) until exhaustion to assess endurance time (limit time, T(lim)). Changes in muscle oxygenation and blood volume were assessed by near infrared spectroscopy (NIRS). The root mean square (RMS) amplitude and the mean power frequency (MPF) from electromyogram (EMG) signals were obtained, as NIRS parameters, from the vastus lateralis. Mean T(lim) was 117 +/- 34 s. The muscle oxygenation and blood volume curves decreased immediately at the beginning of exercise. Maximal deoxygenation occurred at 50% T(lim), and fell by 76.9% from the resting value. Similarly, minimal blood volume was observed at 50% T(lim); it reached a plateau that lasted until the end of exercise. The kinetics of the MPF and RMS curves were inversely related to time. At the last set of exercises (after 75% T(lim)), a steeper RMS curve and an abrupt decrease in the MPF curve were observed. Significant correlations (r) between muscle oxygenation, blood volume, root mean square amplitude and mean power frequency were observed, which ranged from 0.72 to 0.99. These findings suggest that the fatigue resulting from sustained isometric exercise is related to a decrease in oxygenation and blood volume. 相似文献
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Wassim Moalla Abdallah Merzouk Frédéric Costes Zouhair Tabka 《Journal of sports sciences》2013,31(11):1195-1201
Abstract The aim of this study was to examine the time-course of and the relationships between muscle oxygenation, blood volume and myoelectrical manifestations during isometric exercise in children. Twelve healthy children aged 12.5 ± 1.2 years (mean ± s) performed an isometric knee extension at 50% of their maximal voluntary contraction (MVC) until exhaustion to assess endurance time (limit time, T lim). Changes in muscle oxygenation and blood volume were assessed by near infrared spectroscopy (NIRS). The root mean square (RMS) amplitude and the mean power frequency (MPF) from electromyogram (EMG) signals were obtained, as NIRS parameters, from the vastus lateralis. Mean T lim was 117 ± 34 s. The muscle oxygenation and blood volume curves decreased immediately at the beginning of exercise. Maximal deoxygenation occurred at 50% T lim, and fell by 76.9% from the resting value. Similarly, minimal blood volume was observed at 50% T lim; it reached a plateau that lasted until the end of exercise. The kinetics of the MPF and RMS curves were inversely related to time. At the last set of exercises (after 75% T lim), a steeper RMS curve and an abrupt decrease in the MPF curve were observed. Significant correlations (r) between muscle oxygenation, blood volume, root mean square amplitude and mean power frequency were observed, which ranged from 0.72 to 0.99. These findings suggest that the fatigue resulting from sustained isometric exercise is related to a decrease in oxygenation and blood volume. 相似文献
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Myriam Denguezli Imen Ben Chiekh Helmi Ben Saad Monia Zaouali-Ajina Zouhaier Tabka Abdelkrim Zbidi 《Journal of sports sciences》2013,31(12):1351-1359
Abstract The aim of this study was to determine whether endurance training in athletes induces airway inflammation and pulmonary function disorders. Respiratory pattern and function were analysed in ten healthy endurance runners at rest, during sub-maximal exercise, and during the recovery. Inflammatory cells and metabolites (histamine, interleukin-8, and leukotriene E4) were measured in sputum at rest and after exercise. The experiments were conducted on three different occasions (basic endurance training, pre-competitive and competitive periods). In spite of the absence of post-exercise spirometric changes and respiratory symptoms, airway cells counts and inflammatory markers changed significantly. At the beginning of the experiment, athletes' induced sputum showed an abundance of macrophages compared with neutrophils. We found a high percentage of neutrophils during the pre-competitive and competitive periods of the sport season (41% and 37%), a significant increase in macrophage counts during the pre-competitive period (51%), and a significant rise in total cells, interleukin-8, leukotriene E4, and histamine during the competitive period. In conclusion, one year's training increased markers of inflammation in the airways of endurance runners without symptoms or changes in pulmonary function, suggesting that airway inflammation is of insufficient magnitude to markedly impact lung function in healthy athletes. 相似文献
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Mounir Landolsi Lazhar Labiadh Fayçal Zarrouk Khaled Maaref Slaheddine Ghannouchi Zouhair Tabka 《European Journal of Sport Science》2018,18(9):1208-1216
The aims of this study were to (1) propose a method for evaluating shot-putters mechanical power, (2) investigate the relationship between mechanical work of hand action force (WHAF), peak power output (PPO) of different limbs and shot-put performance and (3) show which of these two parameters (WHAF, PPO) were the most appropriate to characterize the explosive abilities of the shot-putter. Twelve junior right-handed shot-putters, practised glide technique shot-put throwers (personal best?=?13.57 ± 1.72 m), participated in this study. Arm and leg force-velocity tests were performed to measure PPO. Kinematic analysis was conducted during a shot-putting event in regular conditions to quantify the WHAF at the release moment and shot-put performance. Significant correlations were found between absolute arm and leg PPO with upper and lower muscle volumes (r?=?.67; p?=?.03; r?=?.76; p?=?.01; r?=?.74, p?=?.01; r?=?.65, p?=?.04). Positive relationships were recorded between absolute arm and leg PPO and shot-put performance (r?=?.67, p?=?.02; r?=?.81, p?=?.004, respectively). Shot-put performance was also closely related to the WHAF (r?=?.93, p?=?.0001) and release velocity parameter (r?=?.86, p?=?.001). The present results confirm that force-velocity test and WHAF constitute useful tools for assessing mechanical power in throwing. The WHAF could be considered as more suitable than force-velocity test. 相似文献
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