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1.
Eur J Appl Physiol ; 124(2): 383-402, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37839038

RESUMO

To improve performance and recovery faster, athletes are advised to eat more often than usual and consume higher doses of simple carbohydrates, during and after exercise. Sports energetic supplements contain food additives, such as artificial sweeteners, emulsifiers, acidity regulators, preservatives, and salts, which could be harmful to the gut microbiota and impair the intestinal barrier function. The intestinal barrier plays a critical function in bidirectionally regulation of the selective transfer of nutrients, water, and electrolytes, while preventing at the same time, the entrance of harmful substances (selective permeability). The gut microbiota helps to the host to regulate intestinal homeostasis through metabolic, protective, and immune functions. Globally, the gut health is essential to maintain systemic homeostasis in athletes, and to ensure proper digestion, metabolization, and substrate absorption. Gastrointestinal complaints are an important cause of underperformance and dropout during endurance events. These complications are directly related to the loss of gut equilibrium, mainly linked to microbiota dysbiosis and leaky gut. In summary, athletes must be cautious with the elevated intake of ultra-processed foods and specifically those contained on sports nutrition supplements. This review points out the specific nutritional interventions that should be implemented and/or discontinued depending on individual gut functionality.


Assuntos
Gastroenteropatias , Esportes , Humanos , Alimento Processado , Resistência Física/fisiologia , Atletas , Esportes/fisiologia , Gastroenteropatias/etiologia
2.
Rev. int. med. cienc. act. fis. deporte ; 22(87): 649-661, sept. 2022. tab, graf
Artigo em Espanhol | IBECS | ID: ibc-211094

RESUMO

El objetivo de este trabajo fue determinar la relación existente entre diferentes metodologías de medición de la carga de entrenamiento en un equipo profesional de baloncesto. 12 jugadores de un mismo equipo fueron sometidos a estructuras de entrenamiento iguales en cuanto a diseño y fueron monitorizados diariamente con frecuencia cardiaca, GPS y percepción subjetiva de esfuerzo. Los resultados indicaron diferencias significativas entre todas las metodologías de control utilizadas. RPE (x2=12.4; P=.015), sRPE (x2=21.5; P<.001), TRIMP (x2=23.5; P<.001), SHRZ (x2=19.3; P<.001) y distancia (x2=21.7; P<.001). Se observó una correlación entre todas ellas exceptuando la variable distancia recorrida; Borg (p=.19; P=79), sRPE (p=.14; P=.299) y sHR-Z (p=.17; P=.197). Estos resultados sugieren que los diferentes métodos de evaluación utilizados para el control de la carga de entrenamiento determinan resultados variables en un equipo de baloncesto profesional. Se consideró que el ratio de esfuerzo percibido por sesión resulta el instrumento más eficaz para el control de la carga de entrenamiento. (AU)


The aim of this study was to determine the relationship between different load assessment methods in a professional basketball team. Twelve professional basketball players of the same team were subjected to the same training plan design and were monitored daily with heart rate monitors, GPS tools and perceived exertion scales. Results suggested that there were significant differences in training load between all monitoring methods: RPE (x2=12.4; P=.015), sRPE (x2=21.5; P<.001), TRIMP (x2=23.5; P<.001), SHRZ (x2=19.3; P<.001) and distance (x2=21.7; P<.001). Correlations were found between RPE and heart rate but not between these methods and the distance travelled during sessions: Borg (p=.19; P=79), sRPE (p=.14; P=.299) and sHR-Z (p=.17; P=.197). These results suggested that different load assessment methods render varying results in a professional basketball team. In this sample, perceived exertion rate was suggested as the best method for assessing training load in professional basketball players. (AU)


Assuntos
Humanos , Adulto Jovem , Adulto , Basquetebol , 34600/métodos , Treinamento Resistido/métodos , Epidemiologia Descritiva , Estudos Retrospectivos , Espanha
3.
Nat Commun ; 13(1): 1911, 2022 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-35396397

RESUMO

Assessing the timing of great megathrust earthquakes is together crucial for seismic hazard analysis and deemed impossible. Geodetic instrumentation of subduction zones has revealed unexpected deformation patterns at subduction segments adjacent to those that hosted recent mega-earthquakes: coastal sites move landward with faster velocities than before the earthquake. Here, we show observations from the largest and best-monitored megathrust earthquakes, and from a scaled analog model, to reveal that these events create coseismic and postseismic deformation patterns typical of a complete gear-like rotation about a vertical axis, hereafter called twisting. We find that such twisting alters the interseismic velocity field of adjacent subduction segments depending on the time since the last earthquake. Early interactions accelerate while late interactions decelerate local kinematics. This finding opens the possibility of using megathrust earthquakes, the characteristics of the twisting pattern, and the ensuing geodetic velocity changes, as a proxy for estimating the timing of the seismic cycle at unruptured segments along the margin.

4.
Sci Adv ; 5(7): eaau9784, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31392263

RESUMO

When a batch of magma reaches Earth's surface, it forms a vent from which volcanic products are erupted. At many volcanoes, successive batches may open vents far away from previous ones, resulting in scattered, sometimes seemingly random spatial distributions. This exposes vast areas to volcanic hazards and makes forecasting difficult. Here, we show that magma pathways and thus future vent locations may be forecast by combining the physics of magma transport with a Monte Carlo inversion scheme for the volcano stress history. We validate our approach on a densely populated active volcanic field, Campi Flegrei (Italy), where we forecast future vents on an onshore semiannular belt located between 2.3 and 4.2 km from the caldera center. Our approach offers a mechanical explanation for the vent migration over time at Campi Flegrei and at many calderas worldwide and may be applicable to volcanoes of any type.

5.
Rev. int. med. cienc. act. fis. deporte ; 17(66): 349-366, jun. 2017. tab, ilus
Artigo em Espanhol | IBECS | ID: ibc-164160

RESUMO

La velocidad de golpeo es uno de los factores fundamentales para el rendimiento en tenis competitivo. El objetivo del estudio fue determinar el efecto de dos métodos de entrenamiento de fuerza sobre la velocidad de golpeo en tenis. 20 jugadores de nivel regional (promedio ± SD: edad 15.5 ± 0.9 años; peso 61.4 ± 7.6 Kg; talla 170.3 ± 9.4 cm) fueron asignados aleatoriamente en tres grupos. Durante 8 semanas a 3 días por sem-1, un grupo realizó un entrenamiento adicional con sobrecargas (SC), un segundo grupo entrenamiento adicional mediante lanzamientos con balón medicinal y banda elástica (L) y un tercer grupo (C, control) únicamente realizó el entrenamiento técnico-táctico. Todos los grupos mejoraron los niveles de fuerza, excepto el grupo control. El grupo SC obtuvo mayores incrementos en la velocidad de servicio. El grupo L mejoró la velocidad de lanzamiento de balón medicinal aunque no hubo transferencia en la velocidad de golpeo (AU)


Nowadays, hitting speed is an important component of tennis performance. The purpose of this study was to determine the effect of two different strength training methods on hitting speed. 20 tennis players were (mean ± SD: age 15.5 ± 0.9 years; weight 61.4 ± 7.6 kg; height 170.3 ± 9.4 cm) randomly divided into 3 groups. During 8 weeks with a frequency of 3 days per week, the first group (SC) performed one additional training with overloads, the second group (L) completed an additional training with medicine ball and elastic band; and the third group (C, control), only completed the technical-tactical training. Each group increased their strength, except the control group. SC group had the best improvement in serve speed. L group increased the strength levels although there was no transfer from the improved strength to the hitting speed (AU)


Assuntos
Humanos , Masculino , Feminino , Adulto Jovem , Tênis/fisiologia , Tênis/estatística & dados numéricos , 34600/métodos , Treinamento Resistido/tendências , Esforço Físico/fisiologia , Declaração de Helsinki , 35170/métodos , 28599
6.
Physiol Behav ; 163: 37-42, 2016 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-27126970

RESUMO

This study compared subjective effort perception with objective physiological measures during high-intensive intermittent exercise performed in normoxia, moderate hypoxia (FiO2: 16.5%) and severe hypoxia (FiO2: 13.5%). Sixteen physically active subjects performed an equal training session on three different days. Training consisted of 6 "all-out" series of continuous jumps lasting for 15s each. Average power output during the jumps was similar in all three conditions (~3200W). Greater hypoxemia was observed in hypoxia as compared to normoxia. Likewise, a significantly higher value in perceived effort was observed after hypoxia training as compared to normoxia training (p<0.05). Whereas blood lactate concentrations immediately after training were not different between normoxia and hypoxia, creatine kinase increased in moderate (p=0.02) and severe (p<0.01) hypoxia compared to normoxia 24h after the training. Perceived fatigue was also significantly elevated 24h after hypoxic exercise only. Heart rate variability pre and 24h after exercise showed a tendency to sympathetic predominance in severe hypoxia as compared to moderate hypoxia and normoxia. In conclusion, a single session of anaerobic exercise can be executed at the same intensity in moderate/severe hypoxia as in normoxia. This type of hypoxic training may be considered as a method potentially to improve the ability tolerating discomfort and consequently also exercise performance.


Assuntos
Exercício Físico/fisiologia , Hipóxia/fisiopatologia , Percepção/fisiologia , Resistência Física/fisiologia , Adulto , Análise de Variância , Frequência Cardíaca , Humanos , Consumo de Oxigênio , Adulto Jovem
7.
Knee Surg Sports Traumatol Arthrosc ; 23(10): 3026-37, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26294054

RESUMO

PURPOSE: The purpose of this study is to review the indications for and outcomes of high tibial osteotomy in the treatment of patients with chronic knee laxity. METHODS: A comprehensive literature review was performed to identify surgical indications and results of high tibial osteotomy for the treatment of chronic knee laxity. RESULTS: Four distinct situations were identified in which a high tibial osteotomy may be advantageous: (1) anterior laxity with varus osteoarthritis, (2) chronic anterior laxity in the setting of varus with lateral ligamentous laxity, (3) chronic anterior laxity in the setting of a high tibial slope, and (4) chronic posterior laxity or posterolateral corner injury. A total of 24 studies were included in this report, including reports of the treatment of 410 knees as well as several review articles. The most frequently reported indication for that addition of HTO was anterior laxity in the setting of varus OA, which was noted to have good results, minimizing anterior knee laxity and allowing return to sports, while reducing the progression of osteoarthritis. More advanced cases in which lateral structures have also become stretched and incompetent are an excellent indication for HTO, with the need for subsequent lateral procedures dependent on the degree of varus laxity and especially hyperextension that is present. Excessive tibial slope has been identified as a cause of ACL reconstruction failure, and some authors have recommended addressing very high slope in revision cases. In knees with chronic posterior or posterolateral instability, correction of alignment first is generally recommended, with subsequent ligamentous procedures performed when instability persists. CONCLUSIONS: Knees with chronic instability pose a difficult treatment challenge. In all cases, the contribution of coronal plane alignment to varus-valgus knee stability must be carefully considered and addressed prior to ligament surgery. Sagittal plane alignment is also key and must not be overlooked. Such considerations drive the indication for osteotomy as well as the type of osteotomy that is chosen. Level of evidence IV.


Assuntos
Instabilidade Articular/cirurgia , Articulação do Joelho/cirurgia , Osteotomia/métodos , Tíbia/cirurgia , Humanos , Reoperação
8.
Physiol Behav ; 143: 35-8, 2015 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-25698671

RESUMO

Scientific debate continues into whether hypoxic training has any performance benefit for athletes, and although this type of training seems popular, to our knowledge little empirical evidence on its popularity with endurance-based athletes exists. To quantify the usage of hypoxic training in endurance-based athletes we asked 203 athletes (amateur = 108, professional = 95) to complete a 17-question survey during 2013-2014 season. Compared to amateurs, professional athletes were 4.5 times (3.0-6.8, odds ratio, 95% confidence limits) more likely to undertake hypoxic training. Live-high train-low was the most popular hypoxic training protocol for athletes (52% professional and 80% amateur) with live-high train-high also used (38% professional, 20% amateur). Compared to amateurs, professional athletes tended to use evidence-based hypoxic training methods, seek advice on hypoxic training from reliable sources and were generally more realistic about the potential performance gains as a result of hypoxic training. Almost one third (25-30%) of all athletes suffered illness during their hypoxic training. Compared to amateurs, professional athletes are more likely to undertake hypoxic training and tend to follow current scientific guidelines. Attenuation of the ill effects that occur during hypoxic training may be accomplished if athletes give more attention to monitoring stress and training levels.


Assuntos
Atletas/psicologia , Desempenho Atlético/fisiologia , Educação Física e Treinamento/métodos , Aptidão Física , Adulto , Feminino , Humanos , Masculino , Oxigênio/administração & dosagem , Adulto Jovem
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