Timing óptimo en la suplementación con creatina para la mejora del rendimiento deportivo / Optimal timing in creatine supplementation to improve sports performance

La creatina es un suplemento deportivo con una elevada evidencia científica sobre sus efectos en el rendimiento y con resultados emergentes en la salud, incluida la de deportistas vegetarianos y adultos mayores. El tipo de creatina y las dosis efectivas, han sido bien estudiadas presentando resultados consistentes. Sin embargo, no son muchos los estudios que han evaluado el momento de la ingesta en cuanto a su interacción con los efectos de la creatina. El objetivo de esta revisión, es analizar la diferente literatura científica existente sobre los protocolos de suplementación con creatina y su interacción con el momento de la ingesta, con el fin de evaluar si existe un efecto mayor de la dosis ergogénica considerada efectiva de creatina cuando esta es ingerida antes, después del entrenamiento o en otro momento del día. Los resultados de este trabajo presentaron diferentes tipos de protocolos y dosis en la suplementación con creatina, a pesar de ser diversos los protocolos mostrados en la literatura, el más efectivo constó de un consumo de 0,3 g/kg/d durante cinco días, seguido de un consumo de 0,03 g/kg/d consiguiendo de esta forma, una mayor reserva de PCr en el músculo esquelético. Los estudios mostraron mayores beneficios cuando la ingesta de creatina se realizó en los momentos cercanos al entreno debido al mayor flujo sanguíneo, apuntando los estudios a mejoras significativas en un consumo post-entreno, debido a que la creatina puede aumentar la formación de glucógeno en el músculo y aumentar la sensibilidad a la insulina

Creatine is a sports supplement with high scientific evidence on its effects on performance and with emerging health's results, including for vegetarian athletes and older adults. The creatine type and effective doses have been well studied, presenting consistent results. However, not many studies have evaluated the ingestion timing in terms of its interaction with the creatine effects. The aim of this review is to analyze the different existing scientific literature on creatine supplementation protocols and their interaction with the timing of ingestion, in order to assess whether there is a greater effect of the ergogenic dose of creatine considered effective when It is ingested before, post workout or at another time of the day. The results of this work presented different types of protocols and doses in creatine supplementation, despite being diverse the protocols shown in the literature, the most effective consisted of a consumption of 0.3 g/kg/d for five days, followed by a consumption of 0.03 g/kg/d, thus achieving a greater reserve of PCr in skeletal muscle. Studies showed greater benefits when creatine intake was carried out in the moments close to workout due to greater blood flow, the studies pointing to significant improvements in post-workout consumption, since creatine can increase the rate of glycogen uptake in muscle and increase insulin sensitivity

Efectos de la suplementación con cafeína sobre la capacidad de producción de fuerza muscular / Effects of caffeine supplementation on the production capacity of muscle strength / Efeitos da suplementação de cafeína na produção de força muscular

El uso de ciertos suplementos puede mejorar el rendimiento deportivo, si bien, la efectividad de éstos es dependiente de las demandas impuestas por el esfuerzo. La suplementación con cafeína ha demostrado ser efectiva, especialmente, en modalidades de resistencia cardiorrespiratoria, sin embargo, son menores el número de estudios que han valorado la efectividad de este suplemento sobre el rendimiento en la función muscular. Con el objeto de valorar el efecto de la suplementación con cafeína sobre la producción de fuerza muscular, se ha realizado una búsqueda de artículos de intervención en las bases de datos Dialnet, Medline, PubMed y Web of Science, en un período comprendido entre 2005 y 2015 y publicados en inglés, español o portugués, que hubiesen valorado los efectos de esta suplementación sobre el rendimiento en fuerza. Los resultados de las distintas investigaciones han demostrado que la suplementación con cafeína mejora el rendimiento en la aplicación de fuerza y potencia con cargas superiores al 50% de una repetición máxima, así como el número de repeticiones realizadas con cargas submáximas, especialmente, a medida que aumenta el número de series realizadas

The use of certain supplements can enhance athletic performance, although the effectiveness of these is dependent on the demands imposed by the effort. Caffeine supplementation has proven effective, especially in patterns of cardiorespiratory endurance, however, they are less than the number of studies that have evaluated the effectiveness of this supplement on performance in muscle function. In order to assess the effect of caffeine supplementation on the production of muscle strength, it has made a search intervention bases Dialnet, Medline, PubMed and Web of Science data, in a period between 205 and 2015 and published in English, Spanish or Portuguese, which had evaluated the effects of this supplementation on strength performance. The results of the various investigations have shown that caffeine supplementation improves performance in the application of force and power with over 50% of one repetition maximum (1RM) loads as well as the number of repetitions with submaximal loads, especially, as the number of sets performed

A utilização de certos suplementos podem melhorar o desempenho atlético, embora a eficácia destes depende das exigências impostas pelo esforço. suplementação de cafeína provou ser eficaz, especialmente em modalidades de resistência cardiorrespiratória, no entanto, eles são menos do que o número de estudos que avaliaram a eficácia deste suplemento sobre o desempenho na função muscular. Para avaliar o efeito da suplementação de cafeína na produção de força muscular, ele realizou uma pesquisa bases de intervenção Dialnet, Medline, PubMed e Web of Science em um período entre 2005 e 2015 e publicada em inglês, espanhol ou português, que avaliou os efeitos dessa suplementação no desempenho de força. Os resultados das várias investigações têm demonstrado que a suplementação de cafeína melhora o desempenho na aplicação de força e de energia com mais de 50% de cargas máximas uma repetição e o número de repetições com cargas submáximas, especialmente quanto o número de série feita

Effects of an Acute Exercise Bout on Serum Hepcidin Levels.

Iron deficiency is a frequent and multifactorial disorder in the career of athletes, particularly in females. Exercise-induced disturbances in iron homeostasis produce deleterious effects on performance and adaptation to training; thus, the identification of strategies that restore or maintain iron homeostasis in athletes is required. Hepcidin is a liver-derived hormone that degrades the ferroportin transport channel, thus reducing the ability of macrophages to recycle damaged iron, and decreasing iron availability. Although it has been suggested that the circulating fraction of hepcidin increases during early post-exercise recovery (~3 h), it remains unknown how an acute exercise bout may modify the circulating expression of hepcidin. Therefore, the current review aims to determine the post-exercise expression of serum hepcidin in response to a single session of exercise. The review was carried out in the Dialnet, Elsevier, Medline, Pubmed, Scielo and SPORTDiscus databases, using hepcidin (and "exercise" or "sport" or "physical activity") as a strategy of search. A total of 19 articles were included in the review after the application of the inclusion/exclusion criteria. This search found that a single session of endurance exercise (intervallic or continuous) at moderate or vigorous intensity (60-90% VO2peak) stimulates an increase in the circulating levels of hepcidin between 0 h and 6 h after the end of the exercise bout, peaking at ~3 h post-exercise. The magnitude of the response of hepcidin to exercise seems to be dependent on the pre-exercise status of iron (ferritin) and inflammation (IL-6). Moreover, oxygen disturbances and the activation of a hypoxia-induced factor during or after exercise may stimulate a reduction of hepcidin expression. Meanwhile, cranberry flavonoids supplementation promotes an anti-oxidant effect that may facilitate the post-exercise expression of hepcidin. Further studies are required to explore the effect of resistance exercise on hepcidin expression.

Effects of beetroot juice supplementation on intermittent high-intensity exercise efforts.

Beetroot juice contains high levels of inorganic nitrate (NO3-) and its intake has proved effective at increasing blood nitric oxide (NO) concentrations. Given the effects of NO in promoting vasodilation and blood flow with beneficial impacts on muscle contraction, several studies have detected an ergogenic effect of beetroot juice supplementation on exercise efforts with high oxidative energy metabolism demands. However, only a scarce yet growing number of investigations have sought to assess the effects of this supplement on performance at high-intensity exercise. Here we review the few studies that have addressed this issue. The databases Dialnet, Elsevier, Medline, Pubmed and Web of Science were searched for articles in English, Portuguese and Spanish published from 2010 to March 31 to 2017 using the keywords: beet or beetroot or nitrate or nitrite and supplement or supplementation or nutrition or "sport nutrition" and exercise or sport or "physical activity" or effort or athlete. Nine articles fulfilling the inclusion criteria were identified. Results indicate that beetroot juice given as a single dose or over a few days may improve performance at intermittent, high-intensity efforts with short rest periods. The improvements observed were attributed to faster phosphocreatine resynthesis which could delay its depletion during repetitive exercise efforts. In addition, beetroot juice supplementation could improve muscle power output via a mechanism involving a faster muscle shortening velocity. The findings of some studies also suggested improved indicators of muscular fatigue, though the mechanism involved in this effect remains unclear.

Mejora del sueño en deportistas: uso de suplementos nutricionales / Sleep improvement in athletes: use of nutritional supplements

El sueño es el estado de reposo físico y mental fundamental en la recuperación del sistema biológico, regulando mecanismos claves y ejerciendo su papel en la homeostasis metabólica. Las recomendaciones lo sitúan en torno a las 8 horas/noche, considerándose que una persona sufre restricción del mismo con tiempos inferiores a 6 horas durante 4 o más noches consecutivas. Éste se ve afectado por diferentes factores ambientales de forma negativa lo que conlleva efectos perjudiciales para la esperanza y la calidad de vida. En el ámbito deportivo, el rendimiento es el factor clave para el éxito en la competición. El sueño es pieza clave en el entrenamiento invisible, jugando un papel fundamental en el rendimiento. Está comprobado que la falta de descanso es desencadenante de una menor capacidad física y de la aparición de trastornos anímicos que dificultan la toma de decisiones. Por ello existen un gran número de investigaciones centradas en estudiar cómo mejorar la calidad y la cantidad del sueño de los atletas a partir de una correcta programación de los entrenamientos y/o una nutrición adecuada, y así minimizar la interferencia o mejorar la fase de conciliación del sueño. La conciliación del sueño, las alteraciones de este los días previos a la competición, el horario de entrenamiento, el estilo de vida del deportista y su influencia en el mismo, la alimentación y la suplementación son los principales temas tratados en esta revisión sobre el sueño en deportistas. Es necesario un mayor número de estudios y un mayor nivel de evidencia para poder conocer y usar las diferentes estrategias que mejoren la calidad del sueño en deportistas

Sleep is the physical and mental resting state which is fundamental for recovery of the biological system, regulating key mechanisms and metabolic homeostasis. It is recommended to sleep around 8 hours/night, and sleep restriction is considered when a person sleeps less than 6 hours during 4 or more consecutive nights. Some environmental factors adversely a ecting sleep will reduce quality of life and may increase mortality risk. Sports performance is obviously a key factor that needs to be successful in a competition period. It is well known that insucient rest reduces physical tness and favors the onset of mood disorders. For that reason, multiple lines of research are focused on nding the best way to improve the quality and quantity of sleep in athletes. It has been found that both nutrition and good training periodization are important to improve the rest and sleep of athletes. To get to sleep and its disruption in the previous days to competition, hour of training, athletes’ lifestyle and its impact, nutrition and supplementation, are the key topics addressed in this review about sleep in athletes. There is an urgent need of more research to understand and use diferent strategies, including nutritional supplements, in improving sleep in athletes

Nutritional needs in the professional practice of swimming: a review.

PURPOSE: Swimming requires developing a high aerobic and anaerobic capacity for strength and technical efficiency. The purpose of this study was to establish the nutritional requirements and dietary strategies that can optimize swimming performance. METHODS: Several related studies retrieved from the databases, Dialnet, Elsevier, Medline, Pubmed, and Web of Science, through keyword search strategies were reviewed. RESULTS: The recommended carbohydrate intake ranges between 6-10-12 g/kg/d, protein 2 g/kg/d, and fat should surpass 20-25% of the daily intake. CONCLUSION: Performance can be optimized with a hydration plan, as well as adequate periodization of supplements, such as caffeine, creatine, sodium bicarbonate, B-alanine, beetroot juice, Vitamin D, bovine colostrum, and HMB.