Skimmed, Lactose-Free Milk Ingestion Postexercise: Rehydration Effectiveness and Gastrointestinal Disturbances Versus Water and a Sports Drink in Physically Active People.

Postexercise hydration is fundamental to replace fluid loss from sweat. This study evaluated rehydration and gastrointestinal (GI) symptoms for each of three beverages: water (W), sports drink (SD), and skimmed, lactose-free milk (SLM) after moderate-intensity cycling in the heat. Sixteen college students completed three exercise sessions each to lose ≈2% of their body mass. They drank 150% of body mass loss of the drink assigned in randomized order; net fluid balance, diuresis, and GI symptoms were measured and followed up for 3 hr after completion of fluid intake. SLM showed higher fluid retention (∼69%) versus W (∼40%; p < .001); SD (∼56%) was not different from SLM or W (p > .05). Net fluid balance was higher for SLM (-0.26 kg) and SD (-0.42 kg) than W (-0.67 kg) after 3 hr (p < .001), resulting from a significantly lower diuresis with SLM. Reported GI disturbances were mild and showed no difference among drinks (p > .05) despite ingestion of W (1,992 ± 425 ml), SD (1,999 ± 429 ml), and SLM (1,993 ± 426 ml) in 90 min. In conclusion, SLM was more effective than W for postexercise rehydration, showing greater fluid retention for the 3-hr follow-up and presenting with low-intensity GI symptoms similar to those with W and SD. These results confirm that SLM is an effective option for hydration after exercise in the heat.

Voluntary Hydration with Skimmed Lactose-Free Milk during Exercise in the Heat: Exploring Effectiveness and Tolerance.

Replacement of fluid losses (dehydration) during sports activities in the heat has been investigated with different beverages. Bovine milk has been recommended for post-exercise rehydration, but its use during exercise may provoke gastrointestinal disorders. This study compared voluntary fluid intake, hydration, and incidence and severity of gastrointestinal (GI) disorders during exercise in the heat under three conditions: no drink (ND), water (W), and skimmed lactose-free milk (SM). Sixteen physically active university students exercised at 32 °C and 70% RH for 90 min at 60-75% HRmax while drinking W or SM ad libitum, or ND assigned at random. A questionnaire explored possible GI disorders. Ad libitum intake was higher (p < 0.05) for water (1206.2 mL) than milk (918.8 mL). Dehydration showed significant differences for SM versus W and ND (W = 0.28% BM; SM = -0.07% BM; ND = 1.38% BM, p < 0.05). Urine volume was significantly higher (p < 0.05) in the W condition (W = 220.4 mL; SM = 81.3 mL; ND = 86.1 mL). Thick saliva, belching, and abdominal pain were higher for SM, but scores were low. Skimmed lactose-free milk is a suitable, effective alternative to be consumed as a hydration beverage during moderate-intensity cycling in the heat for 90 min.

Análisis de las variables de juego en un partido de tenis durante un torneo nacional en costa rica / Analysis of game variables in a tennis match during a national tournament in costa rica / Análise das variáveis de jogo em uma partida de tênis durante um torneio nacional na costa rica

Resumen Rodríguez-Campos, C. y Montoya-Arroyo, J. (2018). Análisis de las variables de juego en un partido de tenis durante un torneo nacional en Costa Rica. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 16(2), 1-22. El tenis de campo ha logrado una gran masificación en las últimas décadas en Costa Rica, razón por la cual cada día se vuelve más importante la aplicación de las ciencias del movimiento humano para lograr un mejor desarrollo y evolución del deporte, sobre todo, en las etapas infantiles y juveniles. Es por ello que esta investigación se enfoca en el análisis descriptivo de diferentes variables del deporte, presentes en los juegos de tres categorías menores. Dentro de la metodología, se encuentra la participación de 36 jóvenes (18 mujeres y 18 hombres), con edades entre los 12 y 18 años, de las categorías U-14, U-16 y U-18. Se evaluaron partidos del tercer Torneo Nacional de Menores, realizado por la Federación Costarricense de Tenis (FCT); se cuantificaron los golpes de derecha, golpes de revés y el saque, así como las dobles faltas, los golpes ganadores, los errores no forzados, los rallies, los golpes por punto jugado, la cantidad de puntos jugados, los games, la cantidad de puntos por game, y el tiempo total del partido. Se realizó una estadística descriptiva, así como un total de 13 ANOVAs de 2 vías de 2x3. En el apartado de resultados, se elaboró un perfil de juego, para cada una de las tres categorías de edades y para ambos sexos, mostrando la manera en la que compiten; además, de las fortalezas y debilidades para cada grupo. Se llega a concluir, el perfil de descripción del tenis durante competencia en jugadores de ambos sexos de categorías menores en Costa Rica ha demostrado ser significativamente diferente en muchas de las variables estudiadas (11 de 13), por lo que este estudio proporciona datos que pueden ser utilizados para desarrollar protocolos de entrenamiento para tenistas juniors de Costa Rica, además de entender el funcionamiento de la competición en cada categoría y sexo.

Abstract Rodríguez-Campos, C. y Montoya-Arroyo, J. (2018). Analysis of game variables in a tennis match during a national tournament in Costa Rica. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 16(2), 1-22. The number of tennis players has increased significantly during the last decades in Costa Rica. Therefore, applying human movement sciences to this sport has become more important in order to improve the sport's development and evolution, especially at the junior level. Consequently, this paper will provide a descriptive analysis of different variables present in three junior categories. As part of the methodology, 36 young players participated (18 male and 18 female) ages ranging from 12 to 18, from the U-14, U-16 and U-18 categories. The matches evaluated were part of the third Junior National Tournament of the Costa Rican Tennis Federation (FCT). The data collected included forehand strokes, backhand strokes, types of serves, double faults, winning blows, unforced errors, rallies, strokes per point, played points, games, points per game, and total duration of the match. Descriptive statistics and thirteen 2x3 2-way ANOVAs were applied. The results section included a game profile for both genders in the three age categories, showing the competition tendency and strengths and weaknesses of each group. It was concluded that the descriptive profile of players of both sexes during competition in the junior categories in Costa Rica has showed to be significantly different in many of the variables studied (11 out of 13). Therefore, this paper provides data that can be used to develop training protocols for Costa Rican junior tennis players and to understand how competition works in each category and sex.

Resumo Rodríguez-Campos, C. y Montoya-Arroyo, J. (2018). Análise das variáveis de jogo em uma partida de tênis durante um torneio nacional na Costa Rica. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 16(2), 1-22. O tênis de campo tem conquistado a massa nas últimas décadas na Costa Rica, e é por isso que cada dia a aplicação das ciências do movimento humano tem se tornado mais importante para alcançar um melhor desenvolvimento e evolução do esporte, especialmente nas etapas infantis e juvenis. Por isso, esta pesquisa se enfoca na análise descritiva de diferentes variáveis do esporte, presentes nos jogos de três categorias menores. Dentro da metodologia, há a participação de 36 jovens (18 mulheres e 18 homens), com idades entre 12 e 18 anos, das categorias Sub-14, Sub-16 e Sub-18. Foram avaliados os jogos do terceiro Torneio Nacional Infantil da Federação de Tênis da Costa Rica (FCT), e quantificados os forehand, backhand e o saque, assim como duplas faltas, golpes vencedores, erros não forçados, o rally, os golpes por ponto jogado, o número de pontos disputados, os games, a quantidade de pontos por game e o tempo total da partida. Foi realizada uma estatística descritiva, bem como um total de 13 ANOVAs 2 vias 2x3. Na seção de resultados, elaborou-se um perfil de jogo, para cada uma das três categorias de idade e para ambos os sexos, mostrando o modo como competem; além disso, as fortalezas e debilidades de cada grupo. Chega-se à conclusão de que o perfil de descrição do tênis durante as competições nos jogadores de ambos os sexos nas categorias em Costa Rica tem provado ser significativamente diferente em muitas das variáveis estudadas (11 de 13), de modo que este estudo fornece dados que podem ser usados para desenvolver protocolos de treinamento para tenistas juniores na Costa Rica, além de entender o funcionamento da competição em cada categoria e sexo.