European journal of applied physiology
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Eur. J. Appl. Physiol. · Jul 2021
Decreased exercise capacity in young athletes using self-adapted mouthguards.
There is evidence of both the preventive effects and poor acceptance of mouthguards. There are various effects on performance depending on the type of mouthguard model. Hemodynamic responses to wearing a mouthguard have not been described. The aim of this study was to investigate the effects of self-adapted mouthguards with breathing channels (SAMGvent). ⋯ Use of a self-adapted mouthguard led to increased metabolic effort and a significant reduction in ventilation parameters. Unchanged oxygen uptake may be the result of cardiopulmonary compensation and increased breathing efforts, which slightly affects performance. These results and the obvious preventive effects of mouthguards support their use in sports.
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Eur. J. Appl. Physiol. · Nov 2020
Biomechanical and metabolic aspects of backward (and forward) running on uphill gradients: another clue towards an almost inelastic rebound.
On level, the metabolic cost (C) of backward running is higher than forward running probably due to a lower elastic energy recoil. On positive gradient, the ability to store and release elastic energy is impaired in forward running. We studied running on level and on gradient to test the hypothesis that the higher metabolic cost and lower efficiency in backward than forward running was due to the impairment in the elastic energy utilisation. ⋯ Efficiency decreased by increasing gradient in both running modalities highlighting the impairment in the elastic contribution on positive gradient. The lower efficiency values calculated in backward running in all conditions pointed out that backward running was performed with an almost inelastic rebound; thus, muscles performed most of the mechanical work with a high metabolic cost. These new backward running C data permit, by applying the recently introduced 'equivalent slope' concept for running acceleration, to obtain the predictive equation of metabolic power during level backward running acceleration.
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Eur. J. Appl. Physiol. · Sep 2020
5 km front crawl in pool and open water swimming: breath-by-breath energy expenditure and kinematic analysis.
Breath-by-breath energy expenditure during open water swimming has not yet been explored in an ecological environment. This study aimed to investigate and compare energetics and kinematics of 5 km swimming, in both swimming pool and open water conditions. ⋯ Small fluctuations were observed for energetic variables in both conditions, but changes in C were lower in swimming pool than in open water. Coaches should adjust the training plan accordingly to the specificity of open water swimming.
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Eur. J. Appl. Physiol. · Aug 2020
Effects of sustained unilateral handgrip on corticomotor excitability in both knee extensor muscles.
Repetitive or sustained simple muscle contractions have been shown to alter corticomotor excitability. The present study investigated the effects of a sustained handgrip contraction with the right hand on motor-evoked potentials (MEPs) in task-unrelated knee extensor muscles and determined whether the effects are influenced by intensity of the handgrip contraction. ⋯ The results of the present study indicate that a unilateral sustained handgrip contraction can differentially alter corticomotor excitability in knee extensor muscles ipsilateral and contralateral to the exercised hand after the handgrip and that the intensity of the handgrip contraction influences corticomotor excitability in both knee extensor muscles after the handgrip.