Fluid intake, hydration status and body mass changes in U-15 judo athletes during a training day

Despite numerous studies related to dehydration there is still a lack of scientific literature presenting hydration status and fluid intake of judo athletes during different periods. Therefore, the aim of this study was to investigate, fluid intake, hydration status and body weight changes of young judo athletes during a typical day of training in preparation period. Twenty-two young judo athletes (age: 12 ± 0.7 y, experience: 3.5 ± 1.1) voluntarily participated in this study. Hydration status and weight were examined in the morning, before and immediately after the training. All athletes trained 90 min and they consumed fluids ad libitum during the exercise. According to morning urine specific gravity (USG) values, 81.2% of the athletes were dehydrated while only 18.8% of the athletes were euhydrated. Pre-training urine measurements showed that 63.64% of the athletes presented dehydration and 77.27% of the athletes completed the training in dehydrated condition despite fluid availability during the training. Mean body weight loss during training was -0.64 ± 0.66%. It can be concluded that young judo athletes presented high prevalence of dehydration as indicated by USG values. Most of the athletes were dehydrated during a typical training day and completed the training in more dehydrated conditions compared to pre training values despite ad libitum fluid intake. It is of great importance to evaluate hydration status of the athletes before training to refrain from common practice of fluid restriction for weight loss and adverse effects of a persistent state of fluid deficit on physical and health related state.

The Hydration Status of Female Collegiate Soccer Players Over Consecutive Training and Match Days / Estado de Hidratación de Jugadoras de Fútbol Universitarias Durante Días de Entrenamiento y Partidos Consecutivos

Abstract Purpose: Hydration has been shown to play a pivotal role in sport. Soccer is a team sport in which the integrity of all players is vital for team performance; thus, individual player hydration status is important. The primary aim of this study was to investigate the hydration status of female collegiate soccer players during regular season. Methods: Sixteen collegiate female soccer players (age: 20.4 ± 0.8 years; height: 163.6 ± 6.9 cm; weight: 65.3 ± 12 kg) provided urine over 9 days to monitor their hydration status. Hydration was determined by urine specific gravity (Usg). Usg was analyzed in the morning (AM) and in the afternoon before practice/game (PM). Results: All 16 players were at least minimally hypohydrated (Usg > 1.010) in the AM on 5 of the 9 days tested. Players had significantly higher Usg values in the AM as compared to PM (F(1,250) = 23.09; p < 0.0001); however, there was no significant time*day interaction (F(1,250) = 1.98; p = 0.16). Conclusion: Data show a high prevalence of hypohydration occurring in this specific population. This sub-optimal hydration status could be a cause for concern in terms of overall performance. Efforts should be made to integrate hydration interventions and daily monitoring to minimize hypohydration in players.

Resumen Propósito: Se ha demostrado que la hidratación juega un papel fundamental en el deporte. El fútbol es un deporte de equipo en el que la integridad de todos los jugadores es vital para su rendimiento; por lo tanto, el estado de hidratación de cada jugador es importante. El objetivo principal de este estudio fue investigar el estado de hidratación de las jugadoras universitarias de fútbol durante la temporada regular. Métodos: Dieciséis jugadoras universitarias de fútbol (edad: 20.4 ± 0.8 años; estatura: 163.6 ± 6.9 cm; peso: 65.3 ± 12 kg) proporcionaron muestras de orina durante 9 días para controlar su estado de hidratación, la cual se determinó por la gravedad específica de la orina (Usg). La Usg se analizó en la mañana (AM) y en la tarde antes del entrenamiento o el juego (PM). Resultados: Las 16 jugadoras estaban al menos mínimamente hipohidratadas (Usg > 1.010) en la AM en 5 de los 9 días medidos. Las jugadoras tuvieron valores Usg significativamente más altos en AM en comparación con PM (F (1,250) = 23.09; p < 0.0001); sin embargo, no hubo interacción significativa de tiempo * día (F(1,250) = 1.98; p = 0.16). Conclusión: los datos muestran una alta prevalencia de hipohidratación en esta población específica. Este estado de hidratación subóptimo podría ser motivo de preocupación en términos de rendimiento general. Se deberían hacer esfuerzos para integrar las intervenciones de hidratación y el monitoreo diario para reducir al mínimo la hipohidratación en las jugadoras.

Resumo Objetivo: Foi demonstrado que a hidratação desempenha um papel fundamental no esporte. O futebol é um esporte coletivo no qual a integridade de todos os jogadores é vital para o desempenho da equipe; portanto, o estado de hidratação de cada jogador é importante. O objetivo principal deste estudo foi investigar o estado de hidratação de universitárias jogadoras de futebol do sexo feminino durante a temporada regular. Métodos: Dezesseis universitárias jogadoras de futebol (idade: 20,4 ± 0,8 anos; altura: 163,6 ± 6,9 cm; peso: 65,3 ± 12 kg) forneceram amostras de urina por 9 dias para monitorar seu estado de hidratação. A hidratação foi determinada pela gravidade específica da urina Usg. Sua Usg foi analisado pela manhã (matutino) e à tarde (vespertino) antes do treino ou jogo. Resultados: As 16 jogadoras estavam minimamente hipohidratadas (Usg > 1.010) no período matutino em 5 dos 9 dias medidos. As jogadoras apresentaram valores de Usg significativamente maiores no período matutino em comparação ao vespertino (F (1.250) = 23,09; p <0,0001); no entanto, não houve interação tempo * dia significativa (F (1.250) = 1,98; p = 0,16). Conclusão: os dados mostram uma alta prevalência de hipohidratação nesta população específica. Este estado de hidratação abaixo do ideal pode ser uma preocupação em termos de desempenho geral. Devem ser feitos esforços para integrar intervenções de hidratação e monitoramento diário para minimizar a hipohidratação em jogadoras.

Effects of skim milk and isotonic drink consumption before exercise on fluid homeostasis and time-trial performance in cyclists: a randomized cross-over study.

BACKGROUND: Hydration status affects endurance performance. Pre-exercise hydration recommendations target the consumption of high carbohydrate and sodium beverages. Milk, due to its carbohydrate and sodium content, may be considered an effective pre-exercise hydration beverage. PURPOSE: In a randomized cross-over trial, we compared the effects of an isotonic sport drink (SPD) with skim milk (SM) consumption before a race, on fluid homeostasis and time-trial performance in road cyclists. METHODS: Male road cyclists (n = 9; age, 26.8 ± 4.78 years) with 10.8 ± 8.56 years of experience in national competitions, consumed either SPD or SM in doses of 350 mL at 3 h and 350 mL at 1.5 h before a 18.6 km time-trial race. Measurements of body mass, urine specific gravity (USG), urine color and time-trial were compared between drinks (group; g) before and after the race (time; t). RESULTS: The two-way ANOVA showed no differences between SPD and SM in body mass (t, p < 0.0001; g, p = 0.89; t × g, p = 0.54), USG (t, p = 0.01; g, p = 0.63; t × g, p = 0.29) and urine color (t, p = 0.01; g, p = 0.54; t × g, p = 0.28) before or after race. Furthermore, no differences on water consumption during the race (p = 0.55) or time-trial performance (p = 0.84) were observed between trials. CONCLUSION: Current results may help athletes with different beverages preferences to increase their options of hydration strategies.

Comparación entre hidratación con leche chocolatada descremada y bebida deportiva posterior al ejercicio físico en militares / Comparison between hydration with chocolate skim milk and sports drink after physical exercise in militaries

Introducción: dos factores importantes han sido descritos como contribuyentes en la aparición de fatiga durante el ejercicio físico: la disminución de las reservas de glucógeno muscular y la pérdida de agua con electrolitos a través del sudor, que favorecen la deshidratación. Debido a esto, la reposición de líquidos y electrolitos posterior al ejercicio físico se transforma en la prioridad para restablecer la homeostasis corporal alterada durante el ejercicio físico. Por su composición nutricional, la leche parece ser una buena alternativa natural como bebida rehidratante posterior al ejercicio físico. Objetivo: comparar la efectividad como bebida de rehidratación de la leche descremada chocolatada contra una bebida deportiva artificial en militares, a partir de la hipótesis de que la leche descremada chocolatada tiene iguales o mejores efectos sobre la hidratación post ejercicio, que una bebida deportiva artificial. Método: 30 militares (23,0 ± 3,2 años) se dividieron en 2 grupos: 1) rehidratación con bebida deportiva con 6 pòr ciento de carbohidratos y relación de Na/K 2:1 (grupo ISO). Rehidratación con leche descremada chocolatada (grupo LECHE). Se evaluó la retención de fluidos a través del peso corporal y la gravedad específica de la orina (GEO) antes y después del ejercicio físico y posterior a las 2 horas de rehidratación. Resultados: se encontraron diferencias significativas (p< 0,05) en la retención de fluidos en el grupo LECHE comparado con el grupo ISO. No hubo diferencias significativas entre la GEO de ambos grupos. Conclusión: Los resultados muestran que la rehidratación con leche descremada es más efectiva en la retención de fluidos y recuperación del peso previo al ejercicio que la bebida deportiva(AU)

ntroduction: Two important factors have been described as contributing to the onset of fatigue during physical exercise: Decreased muscle glycogen stores and the loss of water with electrolytes through sweating, favoring dehydration. Because of this, fluid and electrolyte replacement after physical exercise becomes the priority to restore altered body homeostasis during physical exercise. Due to its nutritional composition, milk appears to be a good natural alternative as a rehydration beverage after exercise. Objective: To compare the effectiveness chocolate skim milk as pots-exercise rehydration beverage with an artificial sports drink in the military, based on the hypothesis that chocolate skim milk has equal or better effects on post-exercise hydration than an artificial sports drink. Method: 30 soldiers (23.0 ± 3.2 years) were divided into 2 groups: 1) rehydration with sports drink with 6 percent carbohydrates and ratio of Na / K 2: 1 (ISO group). Rehydration with chocolate skim milk (LECHE group). Fluid retention was assessed through body weight and the specific gravity of urine (GEO) before and after physical exercise and after 2 hours of rehydration. Results: significant differences were found (p < 0.05) in fluid retention in the LECHE group compared to the ISO group. There were no significant differences between the GEO of both groups. Conclusion: The results show that rehydration with skim milk is more effective in fluid retention and weight recovery prior to exercise than sports drink(AU)

Preexercise urine specific gravity and fluid intake during one-hour running in a thermoneutral environment - a randomized cross-over study.

Urine specific gravity is often used to assess hydration status. Athletes who are hypohydrated prior to exercise tend to ingest more fluid during the exercise, possibly to compensate for their pre exercise fluid deficit. The purpose of this study was to evaluate the effect of additional fluid intake on fluid balance and gastrointestinal tract comfort during 1h running in a thermoneutral environment when athletes followed their habitual fluid and dietary regimes. Sixteen men and sixteen women ingested a 6% carbohydrate-electrolyte solution immediately prior to exercise and then every 15 minutes during two runs, with a consumption rate of 2 mL.kg(-1) (LV, lower volume) or 3 mL.kg(-1) (HV, higher volume) body mass. Urine specific gravity and body mass changes were determined before and after the tests to estimate hydration status. During exercise subjects verbally responded to surveys inquiring about gastrointestinal symptoms, sensation of thirst and ratings of perceived exertion. Plasma glucose, heart rate and blood pressure were also evaluated. Men had higher preexercise urine specific gravity than women (1.025 vs. 1.016 g·mL(-1) HV; and 1.024 vs. 1.017 g·mL(-1) LV) and greater sweat loss (1.21 ± 0.27 L vs. 0.83 ± 0.21 L HV; and 1.18 ± 0.23 L vs. 0.77 ± 0.17 LV). Prevalence of gastrointestinal discomfort increased after 45 min. No significant differences on heart rate, rate of perceived exertion, blood pressure or glycemia was observed with the additional fluid intake. From these results it appears that additional fluid intake reduces body mass loss and thirst sensation. When compared to the men, however, preexercise euhydration was more common in women and an increased fluid intake increases the risk of body mass gain and gastrointestinal discomfort. Key pointsThere seems to be a wide variability in pre-exercise hydration status between male and female and efforts aimed at educating athletes about the importance of pregame hydration must be emphasized.The fluid ingestion during running exercise in a moderate environment reduces body mass loss and thirst sensation, but an increased fluid intake at rates to match the fluid loss might raise the risk of body mass gain in women during prolonged activities.Individual gastric tolerance and familiarization with fluid replacement should be taken into account when providing athletes with strategies for hydration during exercise.