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Hydration in sport and exercise: Water, sports drinks and other drinks
Abstract
There is evidence to suggest that exercise‐induced dehydration can have a negative impact on exercise performance, and restoration of fluid balance should be achieved after exercise. It is equally well known that muscle glycogen must be restored after exercise if subsequent performance is not to be negatively affected. Sports drinks are ideally placed to fill both these roles. However, while muscle glycogen restoration can be comfortably achieved by consumption of solid food, the same is not true for restoration of hydration status.
Clear evidence is available that drinking during exercise can improve performance, provided that the exercise is of sufficient duration for the drink to be emptied from the stomach and absorbed in the intestine. Generally, drinking plain water is better than drinking nothing, but drinking a properly formulated carbohydrate–electrolyte ‘sports’ drink can allow for even better exercise performance.
Of importance for rehydration purposes after exercise is consumption of both an adequate volume of fluid (greater than the net deficit of the sweat volume lost) and quantity of sodium. Without both of these, rehydration will be neither rapid nor complete and maintained. There is, however, no good evidence for the inclusion of any other electrolytes. The current generation of commercially available sports drinks are generally formulated to meet the needs of many athletes in many different situations.
... In contrast, sports drinks are designed to replace fluid and electrolytes lost via sweat during exercise and provide exogenous carbohydrates (CHO) for oxidation and energy production by muscles and the central nervous system (Baker & Jeukendrup, 2011). Most traditional sports drinks and oral rehydration solutions contain varying concentrations of both CHO and electrolytes, commonly known as carbohydrate-electrolyte solutions (CES) (Shirreffs, 2009). Beverages with different compositions are likely to have varying effects on promoting hydration. ...
... The current consensus, established by the American College of Sports Medicine, is that a CHO-consumption of~30e60 g h À1 is recommended during endurance exercise (Thomas, Erdman, & Burke, 2016). Thus, many leading commercially-available sports beverages contain CHO contents of~6% (Shirreffs, 2009). Additionally, although the hallmark of sports drinks is the improvement in performance via increased CHO-derived substrate availability for energy production in active skeletal muscles, these beverages often also contain various electrolytes to facilitate fluid retention, primarily in the extracellular compartment, and thereby improve hydration status. ...
... The collective findings of these studies suggest that milk and CES promote fluid retention and provides sufficient exogenous CHO to maintain glycogen stores and oxidation rates to a similar degree during prolonged exercise. Further, considering that adding 10 g L À1 glucose to milk did not prolong time-to-exhaustion compared with milk without added glucose (Lee et al., 2008) and that the CHO content of milk is similar to that of most sports beverages (Shirreffs, 2009), it is possible that the CHO content of milk, which typically consists of lactose, which can be hydrolyzed to form glucose and galactose, as opposed to the fructose/sucrose/glucose in most sports drinks, is already optimized for performance. Additional research is necessary to assess the influence of milk consumption versus other sports drinks on exercise performance >1 h, as well as its influence on different measures of exercise capacity other than time-to-exhaustion (i.e., time-trial or sprint-tothe-finish performance). ...
Fluid homeostasis is challenged during exercise when fluid availability is limited or when fluid loss is not properly replaced. Sports drinks are designed to improve hydration by stimulating fluid ingestion, reabsorption, and retention. Milk has been suggested to be an alternative hydration source to sports drinks due to its higher electrolyte concentrations and similar carbohydrate content. As milk has a high energy density and viscosity that may present gastric discomfort, attempts have been made to develop beverages from milk byproducts, such as milk permeate, that may be more efficacious for consumption during exercise. However, there is limited literature on milk permeate-based beverages for hydration or performance purposes. This review aims to identify the properties of milk that promote fluid retention, discuss how milk consumption both during or following exercise may impact performance or rehydration, respectively, and explore the scientific evidence regarding the use of milk permeate for sports drink production.
... The hypothesis is that when the "critical temperature" is achieved, the central nervous system decreases the drive to exercise to reduce heat production and protect against neuronal dysfunction (Judelson et al., 2007). When heat stress is elevated and cardiac output is decreased, blood flow to active skeletal muscles may also be reduced, which could cause reduce nutrient and oxygen delivery required to support aerobic metabolism, as such the intensity of exercise must be decreased (Shirreffs, 2009). ...
... Sports drinks often contain electrolytes and carbohydrates, which enhance the rate of water absorption. Overall, these drinks (including milk) reduce the physiological stress related to exercise and promote recovery following exercise (Roy, 2008;Shirreffs, 2009). Therefore consumption of a sports drink or milk will provide a large amount of water in addition to other components, which could otherwise be obtained from foods and supplements (Kenefick & Cheuvront, 2012;Shirreffs, 2009). ...
... Overall, these drinks (including milk) reduce the physiological stress related to exercise and promote recovery following exercise (Roy, 2008;Shirreffs, 2009). Therefore consumption of a sports drink or milk will provide a large amount of water in addition to other components, which could otherwise be obtained from foods and supplements (Kenefick & Cheuvront, 2012;Shirreffs, 2009). ...
Milk and dairy products with their distinct composition of carbohydrates, proteins, fats, and micronutrients are purported to have beneficial effects on human health. They have the potential to enhance exercise performance and recovery and are considered functional sport foods/beverages. This chapter summarizes the current evidence regarding the benefits of dairy products on endurance and resistance exercise, as well as the potential to augment health and performance in a variety of populations including team sport athletes, exercising children and adolescents, and aging adults. The impact of dairy products on weight loss and sleep quality is also discussed.
... The hypothesis is that when the "critical temperature" is achieved, the central nervous system decreases the drive to exercise to reduce heat production and protect against neuronal dysfunction (Judelson et al., 2007). When heat stress is elevated and cardiac output is decreased, blood flow to active skeletal muscles may also be reduced, which could cause reduce nutrient and oxygen delivery required to support aerobic metabolism, as such the intensity of exercise must be decreased (Shirreffs, 2009). ...
... Sports drinks often contain electrolytes and carbohydrates, which enhance the rate of water absorption. Overall, these drinks (including milk) reduce the physiological stress related to exercise and promote recovery following exercise (Roy, 2008;Shirreffs, 2009). Therefore consumption of a sports drink or milk will provide a large amount of water in addition to other components, which could otherwise be obtained from foods and supplements (Kenefick & Cheuvront, 2012;Shirreffs, 2009). ...
... Overall, these drinks (including milk) reduce the physiological stress related to exercise and promote recovery following exercise (Roy, 2008;Shirreffs, 2009). Therefore consumption of a sports drink or milk will provide a large amount of water in addition to other components, which could otherwise be obtained from foods and supplements (Kenefick & Cheuvront, 2012;Shirreffs, 2009). ...
Beyond the fact that whey is a by-product of cheese-making, it is used in the manufacture of a great number of foods and food ingredients including, but not limited to, fermented and unfermented beverages, semisolid foods, food supplements, pharmaceutical goods, coatings, and so on. During the last decade, whey and whey components have been increasingly used in the manufacture of whey-based beverages. These whey-based beverages are consumed either plain or supplemented with some nutraceutical components and/or probiotics/prebiotics. Whey beverages supplemented with fruit juice, milk or milk permeate, or nutraceutical compounds are estimated to occupy a larger stake in the dairy and functional foods market in the near future. Heat-triggered sedimentation is the major challenge of whey-based beverage industry. To overcome this handicap and protect the nutritional value of whey beverages, nonthermal food processing technologies may well be considered as alternatives to heat treatment.
... The hypothesis is that when the "critical temperature" is achieved, the central nervous system decreases the drive to exercise to reduce heat production and protect against neuronal dysfunction (Judelson et al., 2007). When heat stress is elevated and cardiac output is decreased, blood flow to active skeletal muscles may also be reduced, which could cause reduce nutrient and oxygen delivery required to support aerobic metabolism, as such the intensity of exercise must be decreased (Shirreffs, 2009). ...
... Sports drinks often contain electrolytes and carbohydrates, which enhance the rate of water absorption. Overall, these drinks (including milk) reduce the physiological stress related to exercise and promote recovery following exercise (Roy, 2008;Shirreffs, 2009). Therefore consumption of a sports drink or milk will provide a large amount of water in addition to other components, which could otherwise be obtained from foods and supplements (Kenefick & Cheuvront, 2012;Shirreffs, 2009). ...
... Overall, these drinks (including milk) reduce the physiological stress related to exercise and promote recovery following exercise (Roy, 2008;Shirreffs, 2009). Therefore consumption of a sports drink or milk will provide a large amount of water in addition to other components, which could otherwise be obtained from foods and supplements (Kenefick & Cheuvront, 2012;Shirreffs, 2009). ...
Predictive microbiology aims to evaluate the effect of processing, distribution, and storage operations on microbiological food safety. It is based upon the premise that the response of population of microorganisms to environmental factors are reproducible, and that, by characterizing the environment in terms of identifiable, dominant factors controlling growth responses, it is possible, from past observations, to predict the responses of those microorganisms in other, similar environments. Predictive microbiology models represent the microbial responses to the environment. They are based mainly on observations made in synthetic culture media. Models cannot take into account all factors that may affect the microbial growth but select the most influential factors and only model their effects.
The main assumptions of predictive microbiology and risk analysis are discussed in the present chapter. Moreover, the classification of predictive models and application in dairy processing are given. Finally, a case study using the tertiary model Sym’Previus software is presented.
... 14 Minuman yang disarankan adalah jus buah atau sayuran, susu, dan sport drink. 14,28,29 Setelah latihan, atlet perlu melakukan rehidrasi yang bertujuan untuk menggantikan cairan dan elektrolit yang hilang saat latihan. 13,20 Minuman yang disarankan adalah minuman yang mengandung karbohidrat dan elektrolit, antara lain jus buah atau sayuran, susu, dan sport drink. ...
... 13,20 Minuman yang disarankan adalah minuman yang mengandung karbohidrat dan elektrolit, antara lain jus buah atau sayuran, susu, dan sport drink. 14,28,29 Namun, dalam penelitian ini sebagian besar subjek mengonsumsi air dan hanya beberapa yang mengonsumsi minuman karbohidrat maupun minuman elektrolit. Jika hanya mengkonsumsi air tidak menstimulasi rasa ingin minum dan dapat meningkatkan jumlah urin yang keluar yang menyebabkan penurunan asupan dan meningkatkan keluaran. ...
... Beberapa literatur menyebutkan bahwa suhu lingkungan, kelembaban udara dan kecepatan angin adalah faktor yang paling berpengaruh terhadap keringat yang hilang. 16,29 Namun, dalam penelitian ini tidak dilakukan pengukuran suhu lingkungan maupun kelembaban udara. ...
Latar Belakang : Atlet sepak bola merupakan atlet yang melakukan olahraga dengan intensitas tinggi. Atlet sepak bola berpotensi untuk mengalami dehidrasi apabila kehilangan cairan karena peningkatan pengeluaran air melalui keringat dan pernafasan tidak diimbangi dengan konsumsi cairan yang cukup. Atlet remaja memiliki risiko dehidrasi lebih tinggi daripada atlet dewasa. Tujuan penelitian ini untuk menganalisis hubungan konsumsi cairan pada periode latihan dengan status hidrasi setelah latihan pada atlet sepak bola remaja.Metode : Penelitian observasional dengan desain cross-sectional yang melibatkan 47 atlet sepak bola remaja laki-laki (usia 13-16 tahun) di Sekolah Sepak Bola Universitas Diponegoro Semarang. Subjek dipilih dengan simple random sampling. Data yang dikumpulkan meliputi karakteristik subjek, konsumsi cairan, kehilangan berat badan, volume urin, keringat yang hilang selama latihan dan status hidrasi setelah latihan. Latihan pertandingan sepak bola dilakukan selama 70 menit. Konsumsi cairan pada periode latihan diukur dengan menggunakan food recall, keringat yang hilang selama latihan dihitung menggunakan rumus dan status hidrasi setelah latihan diketahui dengan pemeriksaan berat jenis urin. Hasil : Rerata konsumsi cairan pada periode latihan (1678,77±457,99 ml) masih kurang dari kebutuhan (2400-3400 ml). Rerata keringat yang hilang adalah 1364,19±448,68 ml. Semua atlet sepak bola remaja mengalami dehidrasi, sebagian besar mengalami significant dehydration (89,4%) dan yang lain mengalami minimal dehydration (10,6%). Terdapat hubungan yang bermakna antara konsumsi cairan pada periode latihan dan status hidrasi setelah latihan (p<0,05), tetapi tidak terdapat hubungan antara keringat yang hilang selama latihan dan status hidrasi setelah latihan pada atlet sepak bola remaja (p>0,05).Simpulan : Terdapat hubungan yang bermakna antara konsumsi cairan pada periode latihan dan status hidrasi setelah latihan pada atlet sepak bola remaja.
... They can also be preferred as pre-and post-workout drinks. Sports drink can also be defined as a substance consisting of water and other essential micronutrients to help our body recover from stress and meet physiological needs (Shirreffs, 2009). The main purpose of these drinks is to provide the body with carbohydrates and essential minerals to nourish our tissues and organs during activity and to accelerate the overall recovery process during exercise. ...
... In that study, it was noticed that the local mineral water had a Na content of 26 ppm (Lau and Luk, 2002). It was observed that this value was less than other sports drinks sold in the market (Shirreffs, 2009). ...
Dehydration emerges due to lack of fluid balance in the body. In addition, minerals such assodium, potassium, calcium, and magnesium are lost because of dehydration. Athletes losefluids and electrolytes through sweating during exercise, and replacing the lost fluid andelectrolytes is crucial for the continuity of their sports performance. Sports drinks can beconsumed by athletes to replace fluid and electrolytes lost during exercise and to improveperformance. During this period, consumption of sports drinks minimizes dehydration byrestoring the lost mineral and fluid balance. However, the composition of these products,their active ingredients, their effects on sports performance, and their risk factors are mattersof debate. This study was carried out in order to compare sports drinks with the local mineralwater that comes out naturally in the province of Agri. The mineral determinations of thelocal mineral water were made using Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS) instruments. As a result of the analyses, the average sodium (Na) value in the localmineral water was 26.6 ppm, and the magnesium (Mg) average was 7.782 ppm. Nopotassium (K) mineral was detected in Agri local mineral water. Calcium (Ca) mineralaverage was found to be 65.04 ppm, iron (Fe) mineral average 0.0068 ppm, and zinc (Zn)mineral average 0.02457 ppm. Agri natural mineral water contains minerals in similaramounts to sports drinks. Considering these values, it can be a natural alternative to sportsdrinks if potassium mineral and glucose is added to its content, so it can be an alternative tosports drinks
... They can also be preferred as pre-and post-workout drinks. Sports drink can also be defined as a substance consisting of water and other essential micronutrients to help our body recover from stress and meet physiological needs (Shirreffs, 2009). The main purpose of these drinks is to provide the body with carbohydrates and essential minerals to nourish our tissues and organs during activity and to accelerate the overall recovery process during exercise. ...
... In that study, it was noticed that the local mineral water had a Na content of 26 ppm (Lau and Luk, 2002). It was observed that this value was less than other sports drinks sold in the market (Shirreffs, 2009). ...
Dehydration emerges due to lack of fluid balance in the body. In addition, minerals such as sodium, potassium, calcium, and magnesium are lost because of dehydration. Dehydration is commonly seen in athletes during their prolonged and intense exercise periods. Athletes lose fluids and electrolytes through sweating during exercise, and replacing the lost fluid and electrolytes is crucial for the continuity of their sports performance. Sports drinks can be consumed by athletes to replace fluid and electrolytes lost during exercise and to improve performance. During this period, consumption of sports drinks minimizes dehydration by restoring the lost mineral and fluid balance. However, the composition of these products, their active ingredients, their effects on sports performance, and their risk factors are matters of debate. This study was carried out in order to compare sports drinks with the local mineral water that comes out naturally in the province of Agri. The mineral determinations of the local mineral water were made using Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS) instruments. As a result of the analyses, the average sodium (Na) value in the local mineral water was 26.6 ppm, and the magnesium (Mg) average was 7.782 ppm. No potassium (K) mineral was detected in Agri local mineral water. Calcium (Ca) mineral average was found to be 65.04 ppm, iron (Fe) mineral average 0.0068 ppm, and zinc (Zn) mineral average 0.02457 ppm. Agri natural mineral water contains minerals in similar amounts to sports drinks. Considering these values, it can be an alternative to sports drinks.
... In its simplest sense, a sports drink and by inference an energy drink is consumed in association with sport or exerciseeither in preparation for exercise, during exercise itself or as a recovery drink after exercise. By definition, a drink is a liquid substance and as such, water is a main ingredient [76]. ...
... However, it is important at this point to also delineate the difference between sport drinks and energy drinks. The majority of mainstream sports drinks have a carbohydrate content close to 6% weight/ volume and contain small amounts of electrolytes, the main one being sodium [76]. While, in the United States the Food and Drug Administration [77] defines energy drinks (EDs) as "a class of products in liquid form that typically contains caffeine, with or without other added ingredients." ...
... Dehydration by losing more than 2% of body weight may impair endurance performances even during relatively short games such as taekwondo [5,8]. The effect of rehydration with different types of fluid intake such as water or sport drinks on performance has been widely investigated among athletes [9][10][11][12][13][14][15]. However, few studies have inves-tigated the effect of rehydration with mineral water such as Zamzam water on the hydration status of athletes. ...
... To our knowledge, the impact of rehydration with Zamzam water on fitness components such as cardiorespiratory fitness as one of the main fitness components has yet to be investigated. Zamzam water has unique characteristics compared to normal water, including being rich in minerals [12], and being an alkaline fluid (average pH = 8) [15]. Therefore, Zamzam water with its characterestics may help to maintain wholebody fluid homeostasis [16]. ...
Background: The aim of the present study was to examine the effect of rehydration with mineral water on cardiorespiratory fitness in athletes. Methods: Twenty athletes (age 21.7 ± 3 years) underwent a random, crossover-design experimental trial. Three visits were arranged, with the first for baseline measurement. The second visit included three phases (pre-dehydration, post-dehydration, and post-rehydration), with either Zamzam (mineral water) or bottled water (control water) used. The third visit was similar to the second visit, but with an exchange of the type of water used. Cardiorespiratory fitness and blood parameters were evaluated. Results were compared between Zamzam water and bottled water, and between the phases for each type of water. Results: No significant difference was found between Zamzam and bottled water for the cardiorespiratory fitness markers. However, Zamzam water maintained cardiorespiratory functions including VO 2peak, VT1, VT2, and VE peak, even with rehydration equivalent to 100% of the loss in body weight following exercise-induced dehydration (>2% loss in body weight). Rehydration with bottled water was associated with a significant reduction in both the VO 2peak and VE peak. Conclusions: Rehydration with mineral water such as Zamzam is unlikely to impair cardiorespiratory fitness, even with an intake equal to 100% of the loss in body weight.
... Perceptions that sports drinks provide health benefits like hydration, athletic performance, and athletic recovery are reinforced by sports drink advertisements (Shirreffs, 2009). Athletic activity is also featured in energy drink advertising, but while sports drink ads tend to showcase mainstream sports such as football and basketball, energy drink ads tend to include extreme sports such as BMX, car racing, and snowboarding . ...
... The proposed importance of athletic identity is due to the fact that advertising messages for both sports and energy drinks commonly associate the products with sports participation, athletic performance, and hydration (Bragg et al., 2018;Folta et al., 2006;Jenkin et al., 2014;Shirreffs, 2009). If athletic identity does moderate the relationship between ad exposure and product consumption, it would indicate that adolescents are both likely to allocate resources to messages relevant to athletic identity and also are accepting of advertisement claims that these products are helpful for athletes, particularly among those who are athletes themselves. ...
Understanding why sports and energy drinks remain increasingly popular among adolescents despite declines in other sugar sweetened beverages is critical. This study points to memory for advertising exposure and adolescent athletic identity as two aspects that together help to explain consumption. An online survey of U.S. adolescents aged 14-18 (n = 503) was combined with Nielsen data for television and social media advertising expenditures by sports and energy drink brands in participants' designated market areas (DMAs). Advertisement recall mediates the relationship between social media DMA expenditures and sports and energy drink consumption. Recall for television advertisements is related to consumption but is unrelated to television DMA expenditures. Athletic identity moderated the relationship between recall and consumption such that consumption increased as both recall and athletic identity increased, suggesting a role for motivated memory and motivated processing of ad messages based on athletic identity consistent with the limited capacity model of motivated media message processing. Based on these results, we conclude that effectiveness of expenditures in influencing behavior is dependent upon both ad recall and ad relevance, and that athletic identity is an important factor in ad effectiveness in the context of sports and energy drinks advertising.
... In this context, we recently reported that ingestion of an isomaltulose beverage under an exercise-induced dehydrated state was associated with a better net fluid retention, and therefore fluid balance as compared to sucrose [16]. Notably, this response occurred even for an isomaltulose concentration of 6.5%, which is a typical carbohydrate content of many commercial sports drinks [17]. However, it is unclear if the consumption of an isomaltulose beverage under a resting euhydrated state can mediate a reduction in urine output and thus elevate BHI as compared to other carbohydrate-electrolyte beverages. ...
... During the experimental session (see below), the participants consumed either a carbohydrate-electrolyte beverage consisting of 6.5 g per 100 ml solutions of isomaltulose (ISO), a carbohydrate-electrolyte beverage consisting of 6.5 g per 100 ml solutions of sucrose (SUC), or plain water (Control). For both carbohydrate-electrolyte beverage, the carbohydrate and electrolyte concentrations are equivalent to the content of most commercial sports beverages [17]. A list of nutrients contained in each beverage is presented in Table 1. ...
Isomaltulose is a low glycemic and insulinaemic carbohydrate now used as an alternative sweetener in beverages. However, it remains unclear if hydration status may be impacted differently with the consumption of beverages containing isomaltulose as compared to sucrose, a common beverage sweetener. Thirteen young adults (7 women) consumed 1L of a carbohydrate beverage (with low electrolyte content) containing either 6.5%-sucrose, 6.5%-isomaltulose, or water within a 15-min period. For each beverage, beverage hydration index (BHI, a composite measure of fluid balance after consuming a test beverage relative to water) was calculated from urine volume produced over a 3-hour period following ingestion of the carbohydrate beverages relative to water. The change in plasma volume (ΔPV), blood glucose, and lactate concentrations were assessed every 30-min post-beverage consumption. Isomaltulose ingestion attenuated urine production as compared to water and sucrose (P≤0.005) over the 3-hour post-ingestion period. However, no differences were observed between sucrose and water (P=0.055). BHI was 1.53±0.44 for isomaltulose (P≤0.022 vs. sucrose and water) and 1.20±0.29 for sucrose (P=0.210 vs. water). A transient reduction in ΔPV was observed following the ingestion of the isomaltulose beverage (at 30-min, P=0.007 vs. sucrose). Thereafter, no differences in ΔPV between beverages were measured. Increases in blood glucose and lactate, indices of absorption and utility of glucose, were delayed in the isomaltulose as compared to sucrose beverage. In summary, we demonstrated a greater BHI with a carbohydrate-electrolyte beverage containing isomaltulose as compared to sucrose. This may in part be attributed to a delayed absorption of isomaltulose reducing diuresis. (250/250).
... Habitual caffeine and alcohol consumers were therefore excluded to avoid the negative impact of withdrawal effects on the exercise performance and the study. For optimal performance of exercise and to control for the hydration status, participants were instructed to take in food and water about 3 h before coming to the gym (Shirreffs, 2009). Additionally, each of them was given 500 ml of water to be drunk, upon entry into the gym, all at once an hour before the exercise (Shirreffs, 2009). ...
... For optimal performance of exercise and to control for the hydration status, participants were instructed to take in food and water about 3 h before coming to the gym (Shirreffs, 2009). Additionally, each of them was given 500 ml of water to be drunk, upon entry into the gym, all at once an hour before the exercise (Shirreffs, 2009). In controlling for diurnal variations, all participants underwent the training session from 4 to 6 p.m. Baseline ocular measurements were taken after a 30-min sitting in the gym. ...
The study investigated the differential response to a single bout of maximal incremental treadmill exercise between athletes and non-athletes without dry eyes regarding tear secretion, tear film stability, visual acuity (VA), and stereoacuity. Additionally, the study examined the effect of gender and the duration of exercise on exercise-induced changes. Study participants included young university students aged 18–25 years who were athletes (male/female: 13/13) or non-athletes (male/female: 17/9). Participants underwent an aerobic exercise session using a treadmill and following the laid down Bruce treadmill test protocol till exhaustion. Measurements were taken in the order of distance VA, stereopsis, non-invasive tear break-up time (TBUT), and phenol red thread test, at baseline and after the exercise regimen. Within- and between-subject analyses using multiple t-tests with correction for multiple comparisons were performed to determine differences before and after exercise in athletes and non-athletes. Subsequently, ANCOVA was used to assess the influence of gender and the duration of exercise. The mean age (SD) of the athletes and the non-athletes was 22.4 ± 2.1 years and 21.8 ± 2.1 years, respectively (p = 0.357). Before exercise, the athletes had higher TBUT than non-athletes (14.6 ± 2.9 seconds vs. 11.9 ± 3.8 seconds; p = 0.021), but no difference was observed in any other ocular measurements. After exercise, the athletes showed significant improvement in tear secretion with the basal tear secretion increasing from 22.3 ± 2.5 mm to 25.8 ± 1.7 mm (p < 0.001). The non-athletes on the other hand had a borderline increase in tear secretion from 21.42 ± 2.85 mm to 23.73 ± 2.68 mm (p = 0.08). Also, the TBUT was much improved in the athletes after exercise compared to the non-athletes (17.7 ± 2.7 seconds vs. 14.8 ± 2.9 seconds, p = 0.004). Additionally, exercise improved the VA indifferently between the groups, while stereoacuity was unchanged after exercise in either group. Gender had no influence on the differences in the tear function measures between athletes and non-athletes after exercise. The duration of exercise, however, showed a borderline effect on the tear film stability (p = 0.068) after exercise. Our findings support the differential effect of maximal incremental treadmill exercise on tear secretion and tear film stability between athletes and non-athletes. Thus, increased physical fitness and the duration of exercise might be crucial in the improvement of tear function through aerobic exercise.
... 22 The excessive intake of fructose, corn syrup, and other substances found in soda cause an increased risk of gastrointestinal disturbance, delay gastric emptying, and reduces fluid absorption, secreting water into the intestine, increasing the chances of dehydration. 24,26 Nutrition Knowledge. Results suggest that these teams are aware of many items and correct information assessed by the questionnaire. ...
... Studies have correlated this meal with improved cognition and academic performance, as nutrition gives the brain proper building blocks to create and maintain connections. 26,27 Previous studies have reported the deleterious effects of weight cycling and rapid weight loss in weight class sports on mental status. 28,29 Taking breakfast regularly also significantly improves performance among athletes by returning glycogen in the liver and muscle after the overnight fast. ...
Objectives: The study aims to assess the dietary habits and nutritional knowledge of selected Philippine national combat sports athletes and determine the correlation of demographics and sources of nutrition information with participants’ dietary habits and nutrition knowledge. Methods: This cross-sectional study included assessing boxing and taekwondo Philippine national athletes using the Dietary Habits and Nutrition Knowledge Questionnaire: Filipino Version. Data were analyzed using descriptive statistics and inferential statistics between sports comparison and exploratory correlation and regression analyses. Alpha was set at 0.05. Results: A total of 44 participants aged 21+ 3.4 years were able to participate in the study. Responses revealed that 69.44% have fair dietary habits and 73.54% have good nutritional knowledge. Results indicated no significant difference between the two sports in dietary habits and nutritional knowledge (p>0.05). Further analyses revealed that years in playing (r= 0.32, p= 0.04), and sources of nutrition information, precisely strength and conditioning coach (r= 0.36, p= 0.02), and peers (r= 0.39, p= 0.01) have a significant correlation with good dietary habit and nutritional knowledge, respectively. Conclusion: Overall, Filipino national athletes of boxing and taekwondo have fair dietary habits and sound nutritional knowledge. Furthermore, nutritional knowledge sources are possible relevant factors that may affect the dietary habits and nutritional knowledge of combat sports athletes.
... Rata-rata, pada saat olahraga, seseorang akan kehilangan 2-3 L cairan melalui keringat. Dalam keadaan dehidrasi 3-4%, tubuh dapat mengalami penurunan kekuatan otot hingga 2% dan pada dehidrasi 2-7%, penurunan performa daya tahan tubuh terutama terhadap intensitas tinggi dapat terjadi secara signifikan terutama jika olahraga dilakukan pada lingkungan yang panas (>30° C) (Shirreffs 2009). ...
... Sport drink dapat dikonsumsi jika memerlukan mempercepat rehidrasi, penyerapan air, dan recovery setelah latihan, terutama bagi atlet. Hal ini tidak berlaku untuk masyarakat pada umumnya yang jarang melakukan olahraga atau hanya olahraga sekali dalam seminggu (Cohen 2012;Shirreffs 2009). ...
Tujuan penelitian ini untuk mengetahui pengaruh protokol hidrasi dan status hidrasi terhadap performa kekuatan otot tungkai bawah, atensi, dan passing atlet futsal. Metode yang digunakan adalah analitik kuantitatif dengan desain pretes (sebelum penerapan protokol hidrasi) dan postes (setelah 3 minggu penerapan protokol hidrasi) 22 atlet futsal Akademi Mayasari Bandung. Protokol hidrasi yang diberikan yaitu subjek mengonsumsi 500 mL air 1–2 jam sebelum latihan, 250–500 mL air 15 menit sebelum latihan, dan 500 mL–2 L air selama 1 jam latihan dengan interval minum setiap 20 menit. Pengukuran berat badan sebelum dan sesudah latihan, dilakukan menggunakan Tanita Body Composition Scales untuk menentukan status hidrasi berdasarkan kategori WHO. Performa yang diukur yaitu kekuatan otot tungkai bawah dengan leg dynamometer, atensi dengan Grid Concentration Test (GCT), dan perhitungan jumlah passing terhadap dinding sejauh 2 meter selama 30 detik. Analisis data menggunakan uji paired t-test untuk melihat perbedaan performa sebelum dan sesudah penerapan protokol hidrasi, selanjutnya untuk mengetahui pengaruhnya dilakukan analisis two-way Anova. Hasil penelitian menunjukkan bahwa protokol hidrasi berpengaruh terhadap peningkatan kekuatan otot tungkai bawah (p = 0,012), atensi (p = 0,026) dan passing (p = 0,001) pada atlet futsal, namun tidak dengan status hidrasi. The effect of hydration protocol and hydration status on lower leg muscle strength, attention, and passing of youth futsal athletes AbstractThe purpose of this study was to determine the effect of hydration protocol and hydration status on the performance of lower leg muscle strength, attention, and passing of futsal athletes. The method used was quantitative analytic with pretest (before the implementation of hydration protocol) and post-test (after three weeks of hydration protocol implementation) 22 futsal athletes at Mayasari Academy Bandung. The hydration protocol given was that the subjects consumed 500 mL of water 1–2 hours before exercise, 250–500 mL of water 15 minutes before training, and 500 mL – 2 L of water for 1 hour of training with drinking intervals every 20 minutes. Bodyweight measurements, before and after training, using Tanita Body Composition Scales to determine hydration status based on WHO categories. The performance measured was the strength of the lower leg muscles with a leg dynamometer, attention with the Grid Concentration Test (GCT), and the calculation of the number of passes (against the wall as far as 2 meters) for 30 seconds. Data analysis used paired t-test and two-way ANOVA to determine the effect of the hydration protocol on the performance. The results showed that the hydration protocol affected increasing lower leg muscle strength (p = 0.012), attention (p = 0.026), and passing (p = 0.001) in futsal athletes, but not with hydration status.
... The level of electrolytes mentioned in Table 1 indicates that there are relevant differences between the types of beverages analyzed. Of all the electrolytes, it is considered that the most important is sodium because it stimulates the absorption of water and sugar in the small intestine, has a role in maintaining high plasma osmolality and in maintaining the volume of extracellular fluids and stimulating the sensation to drink fluids, so moisturizing [12,13]. The results of this study show that energy drinks have the lowest amount of sodium. ...
... It is important that their quantity in liquids is not increased and the most suitable type of carbohydrates should be of the complex type, the variant in which the energy is released slowly, for a longer period, without a disturbance of the glycemic level. [12,14]. Drinks that contain sugar (simple carbohydrates), in this case energy drinks, cola drinks and lemonade, can cause gastrointestinal disorders, obesity and reduce the amount of fluid that will be absorbed in the small intestine, ie low hydration. ...
The main purpose of this study was to identify the types of water and other drinks used for hydration by those who perform movement activities and also to analyze the quality of these drinks. As a result of performing movement activities, through perspiration, a greater or lesser amount of water is lost from the body. Along with this, a number of nutrients are lost. Given these aspects, the main objective of the research was to understand more correctly, what is involved in proper hydration, which are the factors that must be taken into account to maintain good health. We analyzed and compared the level of the main electrolytes and carbohydrates for different categories of drinks and also measured with the help of two specific devices the level of purity and pH of three categories of drinking water. We indicated general values regarding the ratio of water consumption to weight on the one hand, and on the other hand, we indicated the indicative quantities that should be consumed before, during and after performing medium-level physical effort. As a general conclusion, the importance of sodium, alkaline water and high water purity was highlighted in relation to the categories of beverages analyzed in this study.
... Низкая информированность спортсменов высокого клас- са об индуцированном физическими нагрузками дефици- те жидкости, а также о подходах к его выявлению и кор- рекции является фактором риска снижения физической работоспособности и спортивной результативности [1][2][3]. ...
... Результаты нашего анкетирования показывают, что имен- но в силу низкой осведомленности до 86 % спортсменов не обладают достаточными сведениями для оптимизации своего питьевого режима и, соответственно, лишены воз- можности управлять своим гидратационным статусом. Надо отметить, что величина суммарного объема пот- ребления жидкости (во время нагрузок и после их окон- чания) должна составлять не менее 150 % от ее убыли [3,5]. Следовательно, наши наблюдения показывают, что не менее 2/3 атлетов, чем бы они ни руководствовались - жаждой или указаниями врачей и тренеров по питьевому режиму, попадают в группу риска по развитию гипо-и де- гидратации. ...
... g/dl, dan seriously dehydration apabila nilai BJU >1.030 g/dl. 14,26 Analisis univariat digunakan untuk mendeskripsikan masing-masing variabel. Analisis hubungan konsumsi cairan periode latihan, status hidrasi sebelum latihan dengan status hidrasi setelah latihan uji rank Spearman, yang sebelumnya diuji normalitas data dengan menggunakan uji Saphiro-Wilk. ...
... 13 Minuman yang disarankan adalah jus buah atau sayuran, susu, dan sport drink. 13,25,26 Setelah latihan, atlet perlu melakukan rehidrasi yang bertujuan untuk menggantikan cairan dan elektrolit yang hilang saat latihan. 7,18 Minuman yang disarankan adalah minuman yang mengandung karbohidrat dan elektrolit, antara lain jus buah atau sayuran, susu, dan sport drink. ...
Latar Belakang : Salah satu unsur gizi yang penting adalah air. Atlet remaja memiliki risiko dehidrasi lebih tinggi daripada atlet dewasa. Tidak semua atlet sepak bola memiliki status hidrasi yang baik sebelum latihan, apalagi keringat yang keluar terus menerus selama pertandingan yang tidak diimbangi dengan konsumsi cairan yang cukup akan berpengaruh terhadap terjadinya kelelahan, dehidrasi dan akhirnya berdampak pada performa atlet
Tujuan : menganalisis hubungan status hidrasi sebelum latihan, dan konsumsi cairan selama periode latihan dengan status hidrasi setelah latihan pada atlet sepak bola remaja.
Metode : Penelitian penelitian ini dilakukan dengan desain cross-sectional, populasi adalah atlet mudadi sekolah sepak bola (SSB) UNDIP Semarang. Pemilihan 47 subjek dilakukan dengan acak subjek penelitian berjumlah 47 atlet yang dipilih secara acak. Latihan yang dilakukan adalah permainan sepak bola selama 70 menit. Data identitas subjek diperoleh melalui wawancara menggunakan kuesioner. Data status gizi melalui perhitungan indeks massa tubuh. Konsumsi cairan pada periode latihan (sebelum, selama dan setelah latihan), diperoleh melalui pengamatan dan wawancara menggunakan food recall, dan status hidrasi diketahui dengan pemeriksaan berat jenis urin (BJU).
Hasil : Usia atlet berkisar 13-16 tahun. Sebagian besar atlet kurang mengkonsumsi cairan selama latihan (80,9% atlet) maupun setelah latihan (89,4% atlet). Rerata konsumsi cairan pada periode latihan (1678,77+457,9 ml) lebih rendah dari kebutuhan yang dianjurkan (2400-3400 ml). Hanya 1 atlet (2,1%) yang terhidrasi baik sebelum latihan, 68,8% mengalami significant dehydration. Sedangkan setelah latihan seluruh atlet mengalami dehidrasi, yaitu 89,4% significant dehydration, dan 10,6% minimal dehydration. Ada hubungan konsumsi cairan pada periode latihan (r=-0,297, p=0,043) dan status hidrasi sebelum latihan (r=0,392, p=0,006) dengan status dehidrasi setelah latihan pada atlet sepak bola remaja
Simpulan : status hidrasi sebelum latihan , konsumsi cairan pada periode latihan berhubungan dengan status hidrasi setelah latihan pada atlet sepak bola remaja.
... The eleven papers published in this Nutrition Bulletin Virtual Issue address a range of topics relating to the interaction between nutrition and physical activity/ exercise/sports performance. Eight of these articles focus to a greater or lesser extent on sport as distinct from physical activity (Shirreffs 2009;Leser 2011Leser , 2015James 2012;Reid 2013;Currell 2014;Alderton & Chambers 2015;Egan 2016); two of the papers focus specifically on the issue of physical activity, appetite and energy balance for general health (Blundell 2011;Stensel et al. 2016); and one paper focuses on the role of both diet and exercise in modulating postprandial glucose and triacylglycerol responses, which has relevance for cardiovascular/metabolic health (Edinburgh et al. 2017). ...
... The first paper published in this series (Shirreffs 2009) concerns hydration in sport and exercise. In this paper, Dr. Susan Shirreffs (then at Loughborough University) discusses the need for effective rehydration strategies both during and after exercise. ...
... Consequently, several research studies have been undertaken to ascertain the expeditious replenishment of fluid loss subsequent to dehydration. The available evidence indicates that sports drinks that include CHO and electrolytes are generally more effective for rehydration purposes compared to plain water [29,30]. Nevertheless, recent research has shown that the use of protein-containing solutions for rehydration is more effective in preserving fluid balance compared to the ingestion of sports drinks [13,[16][17][18]. ...
Protein ingestion is known to enhance post-exercise hydration. Whether the type of protein (i.e., whey, casein) can alter this response is unknown. Accordingly, this study aimed to compare the effects of the addition of milk-derived whey isolate or casein protein to carbohydrate-electrolyte (CE) drinks on post-exercise rehydration and endurance capacity. Thirty male soldiers (age: 24 ± 2.1 y; VO 2max : 49.3 ± 4.7 mL/kg/min) were recruited. Upon losing~2.2% of body mass by running in warm and humid conditions (32.3 • C, 76% relative humidity [RH]), participants ingested either a CE solution (66 g/L carbohydrate [CHO]), or CE plus isolate whey protein (CEW, 44 g/L CHO, 22 g/L isolate whey), or CE plus isolate casein protein (CEC, 44 g/L CHO, 22 g/L isolate casein) beverage in a volume equal to 150% of body mass loss. At the end of the 3 h rehydration period, a positive fluid balance was higher with CEW (0.22 L) compared to CEC (0.19 L) and CE (0.12 L). Overall mean fluid retention was higher in CEW (80.35%) compared with the CE (76.67%) and CEC trials (78.65%). The time of the endurance capacity test [Cooper 2.4 km (1.5 miles) run test] was significantly higher in CEC (14.25 ± 1.58 min) and CE [(12.90 ± 1.01 min; (p = 0.035)] than in CEW [(11.40 ± 1.41 min); (p = 0.001)]. The findings of this study indicate that the inclusion of isolate whey protein in a CE solution yields superior outcomes in terms of rehydration and enhanced endurance capacity, as compared to consuming the CE solution alone or in conjunction with isolate casein protein.
... Moreover, PRO would slow down tiredness and improve muscle function as protein-based drink provides the body with fuel for tissue repair and building whereas electrolytes would restore salts lost in sweat, and promote water and CHO assimilation. Blood electrolytes such as potassium, sodium, chloride and bicarbonate also help in regulating nerve and muscle function, as well as maintain acid-base balance and water (Orrù et al., 2018;Shirreffs, 2009). This strategy would allow for enhancing performance as well as reducing heat stroke related complications for soldiers ...
... Because of these inconveniences, the food sector has decided to develop a range of products with high electrolyte content to meet nutritional needs. Nowadays, most sports drinks on the market contain sodium, chloride, and potassium ions, because during physical exertion, there is an increased loss of these minerals [56]. ...
Underlying the dawn of humanity was primarily the search for food and access to drinking water. Over the course of civilization, there has been a significant increase in drinking water quality. By the average of the nutritional standards, the daily water demand is 2.5 L (also including liquid products such as tea, coffee, or soup). However, it is worth noticing that the need is strictly individual for each person and depends on two major factors, namely, epidemiological (sex, age state of health, lifestyle, and diet) and environmental (humidity and air temperature). Currently, our diet is more and more often enriched with isotonic drinks, functional drinks, or drinks bearing the hallmarks of health-promoting products. As a result, manufacturing companies compete to present more interesting beverages with complex compositions. This article will discuss both the composition of functional beverages and their impact on health.
... Kad se dodatak koristi za uspješno postizanje fizioloških, odnosno prehrambenih ciljeva koji se javljaju u sportu, može poboljšati sportske performanse (Burke i Read, 1993). Jedni od široko rasprostranjenih i lako dostupnih suplemenata upravo su sportski napitci koji su po svom sastavu tekuća mješavina ugljikohidrata i elektrolita, a koriste se u svrhu zamjene za tekućinu, punjenja ugljikohidratima i nutritivnih dodataka (Smith, 1992;Shirreffs, 2009). Dokazano je da tijekom vježbi snage i izdržljivosti odgovarajući unos sportskog napitka za očuvanje hidratacije i opskrbu dodatnim ugljikohidratnim supstratom, za mišiće koji iscrpljuju glikogen, poboljšava radnu snagu (Burke i Read, 1993). ...
Cilj provedenog istraživanja bio je provjeriti postoji li razlika kod pojedinaca koji koriste i ne koriste sportske dodatke prehrani u aspektima zadovoljenja potreba vlastitog tijela i stajališta oko toga je li ih vaganje deprimira, smatraju li da imaju lijepo tijelo i svjesnosti o vlastitom tjelesnom izgledu. Također, studija je imala za cilj provjeriti i postojanje razlike između osoba koje se bave i koje se ne bave fitnesom u domenama zadovoljstva raspoloženjem i odnosa s drugim ljudima. U istraživanju su sudjelovale osobe u dobnom rasponu od 18 do 56 godina, od toga 141 muškarac i 552 žene. Rezultati su pokazali kako osobe koje koriste suplemente više brinu o zadovoljavanju potreba vlastitog tijela, imaju izraženiji stav da ih vaganje deprimira, izraženije mišljenje da imaju lijepo tijelo te veću svjesnost o vlastitom izgledu nego osobe koje ne koriste suplemente. Nadalje, osobe koje se bave tjelesnom aktivnošću zadovoljnije su svojim raspoloženjem od osoba koje se ne bave tjelesnom aktivnošću. S druge strane, nije pronađena razlika između osoba koje se bave i osoba koje se ne bave tjelesnom aktivnošću u zadovoljstvu odnosa s drugim ljudima.
... Kad se dodatak koristi za uspješno postizanje fizioloških, odnosno prehrambenih ciljeva koji se javljaju u sportu, može poboljšati sportske performanse (Burke i Read, 1993). Jedni od široko rasprostranjenih i lako dostupnih suplemenata upravo su sportski napitci koji su po svom sastavu tekuća mješavina ugljikohidrata i elektrolita, a koriste se u svrhu zamjene za tekućinu, punjenja ugljikohidratima i nutritivnih dodataka (Smith, 1992;Shirreffs, 2009). Dokazano je da tijekom vježbi snage i izdržljivosti odgovarajući unos sportskog napitka za očuvanje hidratacije i opskrbu dodatnim ugljikohidratnim supstratom, za mišiće koji iscrpljuju glikogen, poboljšava radnu snagu (Burke i Read, 1993). ...
Cilj provedenog istraživanja bio je provjeriti postoji li razlika kod pojedinaca koji koriste i ne koriste sportske dodatke prehrani u aspektima zadovoljenja potreba vlastitog tijela i stajališta oko toga je li ih vaganje deprimira, smatraju li da imaju lijepo tijelo i svjesnosti o vlastitom tjelesnom izgledu. Također, studija je imala za cilj provjeriti i postojanje razlike između osoba koje se bave i koje se ne bave fitnesom u domenama zadovoljstva raspoloženjem i odnosa s drugim ljudima. U istraživanju su sudjelovale osobe u dobnom rasponu od 18 do 56 godina, od toga 141 muškarac i 552 žene. Rezultati su pokazali kako osobe koje koriste suplemente više brinu o zadovoljavanju potreba vlastitog tijela, imaju izraženiji stav da ih vaganje deprimira, izraženije mišljenje da imaju lijepo tijelo te veću svjesnost o vlastitom izgledu nego osobe koje ne koriste suplemente. Nadalje, osobe koje se bave tjelesnom aktivnošću zadovoljnije su svojim raspoloženjem od osoba koje se ne bave tjelesnom aktivnošću. S druge strane, nije pronađena razlika između osoba koje se bave i osoba koje se ne bave tjelesnom aktivnošću u zadovoljstvu odnosa s drugim ljudima.
... During the experimental session (see details below), the participants consumed either a 1L beverage containing electrolytes and either isomaltulose (ISO) or sucrose (SUC) carbohydrates in the amount of 6.5 g per 100 ml of solution. This carbohydrate concentration is commonly found in most commercial sports drinks (Shirreffs 2009). A list of nutrients contained in each beverage is presented in Table 1. ...
Purpose
Isomaltulose is a low glycemic and insulinaemic carbohydrate increasingly used as an alternative sweetener in commercial beverages. While isomaltulose beverages can improve hydration status compared to sucrose-based beverages, it remains unclear if ingestion of an isomaltulose beverage prior to exercise in the heat may improve plasma volume (PV) and thermoregulatory responses.
Methods
Twelve endurance-trained men consumed a 1L carbohydrate beverage containing either 6.5%-sucrose (SUC) or 6.5%-isomaltulose (ISO) 60 min prior to 5 successive, 15-min bouts of moderate-intensity (60% of their pre-determined maximum oxygen uptake) in the heat (32 °C, 50% relative humidity), each separated by a 5 min rest. A 6th bout was performed, wherein the participant adjusted running speed to maximize distance covered within the 15-min period. The change (Δ) in PV, heart rate (HR), body core (rectal and gastrointestinal) and skin temperatures, and whole-body sweat loss were assessed during each exercise bout.
Results
Ingestion of ISO induced a higher ΔPV at 4th bout only (P < 0.001) and lower HR (P = 0.032, main effect of beverage) during exercise compared to those of SUC. Body core and skin temperatures and whole-body sweat loss did not differ between conditions (all P ≥ 0.192, interaction effect). Running distance covered in final exercise bout tended to increase (~ 5%) in ISO versus SUC (P = 0.057, d = 0.64).
Conclusions
Relative to a sucrose-based beverage, ISO ingestion prior to exercise in the heat reduced cardiovascular strain by preserving PV and attenuating HR, albeit with no corresponding benefit on thermoregulatory function. The former response may facilitate improvements in exercise performance.
... The effects of rehydration with different types of fluid intake such as water or sport drinks on performance have been widely investigated among athletes [7][8][9][10][11][12][13]. However, there is a lack of studies that have investigate the effect of rehydration with Zamzam water on hydration status among athletes. ...
Background: the present study aimed to examine the effect of rehydration with mineral water on cardiorespiratory fitness in athletes. Methods: Twenty athletes (21.7±3 years) randomly underwent a crossover design experimental trial. Three visits were arranged. The first visit was for baseline measurement. The second visit included three phases (pre-dehydration, post-dehydration, and post-rehydration), and either Zamzam (mineral water) or bottled water (control water) was used. The third visit was similar to the second visit with an exchange for the type of water. Cardiorespiratory fitness and blood parameters have been evaluated. Data were analyzed to compare the results of Zamzam water with bottled water and to compare the phases for each type of water. Results: although there was no significant difference found between Zamzam and bottled water in the cardiorespiratory fitness markers, Zamzam water maintained cardiorespiratory function including VO2peak, VT1, VT2, and VEpeak even with rehydration equal to 100% of losing body mass following exercise-induced dehydration (>-2% body mass), where rehydration with bottle water reported a significant reduction in both VO2peak and VEpeak. Conclusion: rehydration with mineral water such as Zamzam water may not impair cardiorespiratory fitness even with an amount equal to 100% of losing body mass.
... be to some extent common. This may also happen in situations of diminished5 fluid intake or as a result of consumption of diuretics. The loss of body fluids outstripping the amount which 1 is taken in, interrupting the delicate equilibrium of minerals in body fluids, culminates in dehydration. ...
Water is an essential component in terms of having a role in building of human body. The total body watercontent must be adequately maintained for the health and wellbeing of an individual. Water intake as well aswater loss is governed by efficacious homeostatic mechanisms which are receptive to even minute changessuch as hundred milliliters. Water deficit happens as hypohydration when fluid intake is not sufficient to replacefluid losses. When water loss exceeds the amount of water consumed, dehydration results. Mild dehydration isdescribed as fluid loss being around 1-2% of total body fluids. Severe dehydration occurs with fluid loses over5%. Dehydration has remarkable consequences including effect on body temperature, respiratory rate, mentalfunctioning and muscle endurance. Overall, the role of water as a necessary nutrient is indispensable.Consequently, appropriate hydration status is extremely imperative for health and wellbeing of an individual.1 The human body contains around 70% of water. In terms of body weight water makes up 75% in infants and55% in elderly. Water is necessary for cellular homeostasis as well as life. Still plentiful unanswered2 questions exist regarding this extremely imperative constituent of our body and our diet. The water in the1 body has diverse physiological roles. These include being required for breathing for oxygen transport to thecells, metabolism, digestion and absorption of nutrients, detoxification of the body, regulation of body1 temperature, upkeep of equal osmotic pressure in cells as well as extracellular space etc. Water should betreated as vital nutrient in diet. Accordingly, it is imperative for health to have total body water (TBW) contentin appropriate standards.
... But now a day's sports drinks are made of with different combinations of nutrients so diverse sports drinks are available in the market. Therefore intake of sports drinks helps us to maintain our intra cellular and extracellular water balance (Shirreffs, 2009). ...
Optimal hydration is an essential consideration for athletic performance and it involves activities before, during and after exercise. Hence, adequate hydration not only provides benefits for health but also facilitate to maintain athletic performance. Therefore, the objective of the present study is to evaluate the importance of sports drinks as a performance prerequisites. The central aim of sports drinks utilization differ according to the mode of exercise regime but from a hydration point of view it depends upon rapid fluid absorption, reduction of physiological stress and faster recovery after exercise. So, proper intake of different essential macro and micro nutrients will help our body to hydrate. Sports drinks is a such a product which contain almost all the things which we lost during sports performance. Similarly, dehydration is a condition which cause negative impact on sports performance. The performance of the athlete is very much depends upon their hydration point of view, which may lead to cause both psychological as well as physiological illness. During activity the major fluid loss occurs through sweat. Thus it causes increment of heart rate, body temperature and also reduces the fluid absorption rate, making out body resistive against the minimum demand of work. All these problems can be overcome with the help of isotonic sports drinks. It helps replenish the lost fluid and also provide essential electrolytes and carbohydrates to the athletes which ultimately helped them to execute better performance output.
... Seemingly marginal improvements in late-race performance, therefore, can substantially affect race outcomes. While a plethora of studies have compared the impact of consumption of sports drinks vs. water on performance and have been reviewed elsewhere (Shirreffs and Maughan, 2000;Shirreffs, 2009;Temesi et al., 2011;Orru et al., 2018), none to our knowledge have examined how rehydration with these distinct solutions may differentially impact performance during the important final stages of a race, i.e., the final push to the finish line after a dehydrating exercise bout. To our knowledge, no previous studies have compared the rehydration capabilities of a beverage containing ultra-filtered deproteinized milk and a traditional sports drink and their subsequent influence on performance. ...
Dehydration ≥2% loss of body mass is associated with reductions in performance capacity, and carbohydrate (CHO)-electrolyte solutions (CES) are often recommended to prevent dehydration and provide a source of exogenous carbohydrate during exercise. It is also well established that performance capacity in the heat is diminished compared to cooler conditions, a response attributable to greater cardiovascular strain caused by high skin and core temperatures. Because hydration status, environmental conditions, and carbohydrate availability interact to influence performance capacity, we sought to determine how these factors affect push-to-the-finish cycling performance. Ten young trained cyclists exercised at a moderate intensity (2.5 W·kg−1) in a hot-dry condition [40°C, 20% relative humidity (RH)] until dehydration of ~2% body mass. Subjects then consumed either no fluid (NF) or enough fluid (water, WAT; Gatorade®, GAT; or GoodSport™, GS) to replace 75% of lost body mass over 30 min. After a 30-min light-intensity warm-up (1.5 W·kg−1) in a 35°C, 20% RH environment, subjects then completed a 120-kJ time trial (TT). TT time-to-completion, absolute power, and relative power were significantly improved in WAT (535 ± 214 s, 259 ± 99 W, 3.3 ± 0.9 W·kg−1), GAT (539 ± 226 s, 260 ± 110 W, 3.3 ± 1.0 W·kg−1), and GS (534 ± 238 s, 262 ± 105 W, 3.4 ± 1.0 W·kg−1) compared to NF (631 ± 310 s, 229 ± 96 W, 3.0 ± 0.9 W·kg−1) all (p < 0.01) with no differences between WAT, GAT, and GS, suggesting that hydration is more important than carbohydrate availability during exercise in the heat. A subset of four subjects returned to the laboratory to repeat the WAT, GAT, and GS treatments to determine if between-beverage differences in time-trial performance were evident with a longer TT in thermoneutral conditions. Following dehydration, the ambient conditions in the environmental chamber were reduced to 21°C and 20% RH and subjects completed a 250-kJ TT. All four subjects improved TT performance in the GS trial (919 ± 353 s, 300 ± 100 W, 3.61 ± 0.86 W·kg−1) compared to WAT (960 ± 376 s, 283 ± 91 W, 3.43 ± 0.83 W·kg−1), while three subjects improved TT performance in the GAT trial (946 ± 365 s, 293 ± 103 W, 3.60 ± 0.97 W·kg−1) compared to WAT, highlighting the importance of carbohydrate availability in cooler conditions as the length of a push-to-the-finish cycling task increases.
... In young children, both athletes or not, the increased intake of soft drinks or the consumption of food rich in SF could have a negative impact on bone health and performance due to the impact of these on calcium absorption. This is the reason why it may be important to suggest using unsweetened drinks (water and milk) or orange juice, or sports drinks but only with small amounts of carbohydrate (<2%) and moderate amounts of sodium (37) and fortified with calcium in order to obtain rehydration and reduce or prevent loss of BMD. Furthermore, following a healthy diet rich in unsaturated fat is also suggested. ...
There is growing recognition of the role of diet and physical activity in modulating bone mineral density, bone mineral content, and remodeling, which in turn can impact bone health later in life. Adequate nutrient composition could influence bone health and help to maximize peak bone mass. Therefore, children’s nutrition may have lifelong consequences. Also, physical activity, adequate in volume or intensity, may have positive consequences on bone mineral content and density and may preserve bone loss in adulthood. Most of the literature that exists for children, about diet and physical activity on bone health, has been translated from studies conducted in adults. Thus, there are still many unanswered questions about what type of diet and physical activity may positively influence skeletal development. This review focuses on bone requirements in terms of nutrients and physical activity in childhood and adolescence to promote bone health. It explores the contemporary scientific literature that analyzes the impact of diet together with the typology and timing of physical activity that could be more appropriate depending on whether they are children and adolescents to assure an optimal skeleton formation. A description of the role of parathyroid hormone (PTH) and gut hormones (gastric inhibitory peptide (GIP), glucagon-like peptide (GLP)-1, and GLP-2) as potential candidates in this interaction to promote bone health is also presented.
... During the experimental session (see below), the participants consumed one of three carbohydrates-electrolytes beverages consisting of 6.5 g of isomaltulose (ISO), 6.5 g of sucrose (SUC), and 3.25 g of glucose plus 3.25 g of fructose (G + F) as carbohydrates per 100 ml solutions, respectively. These carbohydrate concentrations are commonly found in commercial sports beverages [23]. A list of nutrients contained in each beverage is presented in Table 1. ...
PurposeIsomaltulose is a low glycemic and insulinaemic carbohydrate available as a constituent in sports drink. However, it remains unclear whether postexercise rehydration achieved by isomaltulose drink ingestion alone differs as compared to other carbohydrates.Methods
Thirteen young men performed intermittent exercise in the heat (35 °C and relative humidity 40%) to induce a state of hypohydration as defined by a 2% loss in body mass. Thereafter, participants were rehydrated by ingesting drinks equal to the volume of body mass loss with either a mixture of 3.25% glucose and 3.25% fructose, 6.5% sucrose (SUC), or 6.5% isomaltulose (ISO) within the first 30 min of a 3-h recovery. The change in plasma volume (ΔPV) from pre-exercise baseline, blood glucose, and plasma insulin concentration were assessed every 30-min.ResultsΔPV was lower in ISO as compared to SUC until 90 min of the recovery (all P ≤ 0.038) with no difference thereafter (all P ≥ 0.391). The ΔPV were paralleled by concomitant changes in blood glucose levels that were greater in ISO as compared to other drinks after 90 min of the recovery (all P ≤ 0.035). Plasma insulin secretion, which potentially enhances renal sodium reabsorption and fluid retention, did not differ between the trials (interaction, P = 0.653). ISO induced a greater net fluid volume retention as compared to SUC (P = 0.010).Conclusion
We showed that rehydration with an isomaltulose drink following exercise-heat stress induces comparable recovery of PV and a greater net fluid retention as compared to other drinks, albeit this response is delayed. The delayed water transport along with glucose absorption may modulate this response.This trial was registered in 25th Sep 2019 at https://www.umin.ac.jp/ as UMIN000038099.(249/250)
... In SPD, appearance liking increased significantly in all viscosity ranges (Table 3). Once the consumer learned the importance of hydration in elderly people with swallowing difficulties, they might have considered the sports drink to be a good source of hydration, as it was designed for rehydration during or after exercise [52]. ...
: Most people tend to think that healthy foods do not taste good. This view could have
a negative impact on the taste of the food that people eat for health. However, if health-related
information is provided to avoid negative aspects, acceptability may improve. Thus, this study
investigated changes in consumers’ sensory perception of thickened beverages before and after the
provision of dysphagia-related health information. Sixty young (19–39 years old) and middle-aged
(40–64 years old) consumers participated in two experiment sessions conducted one week apart.
The first session proceeded without any information and the second provided information about
dysphagia and the need for dietary modification before evaluation. Three beverages (orange juice,
red bean water, and sports drink) were used in nectar-like (51–350 cP) and honey-like (351–1750 cP)
forms; original beverage samples (0%) were used as the control. Consumers were asked about
acceptability, liking the flavor, intensity, and general health interest (GHI). An analysis of variance
was performed to show the change in flavor rating and acceptability between the two sessions.
Although there were age-related differences in response to the samples, thickened beverages were
rated as more acceptable, in terms of their characteristics (swallowing, viscosity, and mouthfeel) after
the information was provided. There were no significant differences for the 0% samples. The mean
GHI values were 3.97 ± 0.85 and 4.81 ± 0.68 for the young and middle-aged groups, respectively.
High and low GHI groups were analyzed. The high GHI group showed significant differences
in acceptability in the informed evaluation, whereas the low GHI group was not influenced by
the information.
... Consumption of fluids containing carbohydrates and electrolytes is recommended before and during exercise in a hot environment to maintain muscle glucose metabolism and fluid balance as well as physiological function, including thermoregulatory and cardiovascular responses [1][2][3]. Conventional sports drinks contain carbohydrates such as glucose, fructose, maltodextrin, and sucrose. Isomaltulose (ISO) is a naturally occurring disaccharide composed of α-1, 6-linked glucose, and fructose, in contrast to the α-1, 2glycosidic bond found in sucrose (SUC). ...
Isomaltulose is a low glycemic and insulinemic carbohydrate available as a constituent of sports drinks. However, it remains unclear whether thermoregulatory responses (sweating and cutaneous vasodilation) after isomaltulose drink ingestion differ from those of sucrose and water during exercise in a hot environment. Ten young healthy males consumed 10% sucrose, 10% isomaltulose, or water drinks. Thirty-five minutes after ingestion, they cycled for fifteen minutes at 75% peak oxygen uptake in a hot environment (30 °C, 40% relative humidity). Sucrose ingestion induced greater blood glucose concentration and insulin secretion at the pre-exercise state, compared with isomaltulose and/or water trials, with no differences during exercise in blood glucose. Change in plasma volume did not differ between the three trials throughout the experiment, but both sucrose and isomaltulose ingestions similarly increased plasma osmolality, as compared with water (main beverage effect, p = 0.040)—a key response that potentially delays the onset of heat loss responses. However, core temperature thresholds and slopes for heat loss responses were not different between the trials during exercise. These results suggest that ingestion of isomaltulose beverages induces low glycemic and insulinemic states before exercise but does not alter thermoregulatory responses during exercise in a hot environment, compared with sucrose or water.
... Dehydration has been shown to decrease performance by impairing cognitive function and weakening muscle contraction (12). The recovery process also relies on hydration because of the role of water in maintaining blood volume, regulating body temperature, and promoting muscle repair (69). Athletes should then aim to consume 2-4 L per day and 150% of the fluids lost after exercise sessions (77). ...
The rapid growth in trick progression for competitive snowboarding over the past 20 years has resulted in increased physical demands required from snowboarding athletes. Despite a wealth of knowledge surrounding strength and conditioning principles for other sports, researchers are yet to address the novel strength and conditioning challenges faced by the freestyle nature of competitive snowboarding. This article, therefore, offers practitioners strategies to address the unique considerations surrounding cultural qualities, injury prevention, unstable surface training, skill acquisition, and recovery strategies for the effective implementation of strength and conditioning interventions for snowboarding athletes.
... Yeterli sıvı tüketimi durumunda, egzersiz başlangıcında vücutta, sıvı miktarı denge halindedir. Antrenman esnasında ise yoğun terlemeye bağlı olarak bu denge bozulur (Wilmore ve Costill, 2004;Shirreffs, 2009). ...
The Investigation of Fluid Loss in Different Endurance Training
Abstract
The aim of this study is to examine the effects of endurance training in two different environments (land and water) on the
amount of body fluid. 16 male athletes who have taken swimming training voluntarily participated in this study [(mean ± SD)
age: 20.06 ± 1.91 years; height: 178.06 ± 7.84cm; body weight: 72.87 ± 6.91kg; body fat percentage: 9.94 ± 3.18]. In the study,
the athletes were randomly divided into 2 equal groups (8 land training groups, 8 underwater exercise groups) and a total of 2
hours of endurance training was applied with 15 minutes of warm-up. In the study, after the first applications were completed,
a break was given for 24 hours, after which the land training group applied in-water exercise and the in-water exercise group
applied land training. In the meantime, body composition measurements (body weight, body fluid amount, muscle mass, body
fat percentage), urine density and body temperature were measured before and just after the two-hour endurance training. For
the statistical analysis paired sample t-test was used. As a result of the statistical analysis, it was determined that there was a
significant difference in body weight, body fluid amount, muscle mass, body fat percentage and body temperature (p <0,05),
but there was no statistically significant difference in urine density (p> 0,05). As a result, it was determined that there are
statistically significant changes in body fluid amount, muscle ratio and body temperature values in endurance exercises
performed in both environments.
Keywords: Endurance, Dehydration, Urine specific gravity, Body composition
... Yeterli sıvı tüketimi durumunda, egzersiz başlangıcında vücutta, sıvı miktarı denge halindedir. Antrenman esnasında ise yoğun terlemeye bağlı olarak bu denge bozulur (Wilmore ve Costill, 2004;Shirreffs, 2009). ...
Yapılan bu çalışmanın amacı iki farklı ortamda yapılan (karada ve suda) dayanıklılık antrenmanının vücut sıvı miktarı üzerine etkilerinin incelenmesidir. Bu çalışmaya yüzme eğitimi almış [(X ̅+ss) yaş: 20,06±1,91 yıl; boy: 178,06±7,84cm; vücut ağırlığı: 72,87± 6,91kg; vücut yağ yüzdesi: 9,94±3,18] olan 16 erkek sporcu gönüllü olarak katılmıştır. Çalışmada sporcular rastgele örneklem seçim yöntemi ile 2 eşit gruba ayrılmış (8 kara antrenmanı gurubu, 8 su içi egzersiz grubu) ve 15 dakikalık ısınma ile birlikte toplam 2 saat dayanıklılık antrenmanı uygulamıştır. Çalışmada ilk uygulamalar tamamlandıktan sonra 24 saat ara verilmiştir. Sonrasında kara antrenman grubu su içi egzersiz, su içi egzersiz grubu ise kara antrenmanı uygulamıştır. Bu esnada iki saatlik dayanıklılık antrenmanı öncesi ve hemen sonrası vücut kompozisyonu ölçümleri (vücut ağırlığı, vücut sıvı miktarı, kas kütlesi vücut yağ yüzdesi), idrar yoğunluğu ve vücut sıcaklığı ölçümleri yapılmıştır. İstatistiksel analizlerde eşleştirilmiş örneklerde t-testi kullanılmıştır. Yapılan istatistiksel analiz sonucunda vücut ağırlığı, vücut sıvı miktarı, kas kütlesi, vücut yağ yüzdesi ve vücut sıcaklığı değerlerinde anlamlı fark olduğu (p<0,05), idrar yoğunluğunda ise istatistiksel olarak anlamlı bir fark olmadığı (p>0,05) belirlenmiştir. Sonuç olarak her iki ortamda da yapılan dayanıklılık egzersizlerinde vücut sıvı miktarı, kas oranı ve vücut sıcaklığı değerlerinde istatistiksel olarak önemli değişiklikler olduğu tespit edilmiştir.
... Hasil ini dapat dijelaskan oleh ketersediaan karbohidrat dalam minuman olahraga selama lari 3000 m dan pemu-lihan, berkontribusi terhadap glikolisis yang dipertahankan selama berlari, terutama pada kecepatan tinggi di treadmill. Perlu dicatat bahwa peningkatan kecil karbohidrat meningkatkan pengambilan glukosa dan cairan (Shirreffs, 2009), memastikan pasokan energi berkelanjutan. Hasil ini sesuai dengan penelitian Lee et al. (2011) yang melaporkan bahwa dalam lingkungan yang panas (32 C dan 65% rh), kapasitas daya tahan yang lebih besar dengan minuman isotonik (1,5 L) sekitar 17,7 menit lebih lama daripada dengan air dan sekitar 13,5 menit lebih lama dibandingkan dengan plasebo dalam aktivitas fisik aktif. ...
Ada kepercayaan umum bahwa minuman istonik berpotensi meningkatkan daya tahan dan aldosterone pada saat latihan dan pemulihan.Namun kepercayaan itu perlu dikaji ulang karena masih bisa untuk diperdebatkan dan lebih banyak lagi bukti empiris. Penelitian ini bertujuan untuk menguji minuma isotonik, air dan kontrol pada respon fisiologis, termasuk kapasitas daya tahan dan aldosterone pada saat latihan dan pemulihan pada saat cuaca panas. Dua belas atlet sepakbola prosseional dari Khon Kaen FC, Thailand yang terlibat dalam penelitian ini. Lari 3000 m, pemulihan 1 jam, dan waktu untuk uji kelelahan dilakukan dalam penelitian ini. Hasil penelitian menunjukkan tidak adanya respon fisiologis selama lari 3000 m dan pada saat pemulihan, denyut jantung lebih rendah dalam uji coba minuman isotonik dibandingkan dengan air dan control. Adanya perbedaan suhu oral, detak jantung, aldosteron, glukosa darah, dan natrium pada saat tes kapasitas daya tahan. Dapat dikatakan bahwa konsumsi minuman isotonik dapat meningkatkan kapasitas daya tahan dan mempertahankan aldosteron lebih efektif daripada dengan atau tanpa air yang mungkin disebabkan oleh peningkatan retensi cairan.
... This result could be explained by the availability of carbohydrates in the sports drink during 3000 m run and recovery, contributing to maintained glycolysis during running, particularly at high speed on the treadmill. It is worth noting that a small elevation in carbohydrates promotes glucose and fluid uptake (Shirreffs, 2009), ensuring sustained energy supply. This result agrees with the study of Lee et al. (2011) who reported that in a hot environment (32 ˚C and 65% rh), the greater endurance capacity with a sport drink (1.5 L) was about 17.7 min longer than with water and about 13.5 min longer than with placebo in physically active males. ...
This study was designed to investigate the influence of isotonic sports drink ingestion during exercise and recovery on subsequent endurance capacity, aldosterone, and other physiological responses in the heat. Twelve male well-trained endurance athletes (27.55±3.87 yrs) performed three experimental trials in which they ingested a sports drink (750 ml), water only or none. Each trial consisted of 3000 m run, 1 h recovery, and time to exhaustion test. The trials were randomized and separated by seven days. Drinks were administered in a crossover design, with the double-blind provision of sports drink and water. Blood samples were collected before and immediately after 3000-m, following recovery, and at exhaustion. A repeated-measures ANOVA test revealed no differences in the physiological responses before and after 3000 m run (p>0.05). After recovery, heart rate was significantly (p=0.050) lower in the sport drink trial than with water and control, with no differences were noted in the other physiological responses (p>0.05). At exhaustion, however, the data showed no differences in oral temperature and heart rate, but the differences were shown in aldosterone, blood glucose, and sodium (p<0.05). A post hoc Bonferroni test revealed that aldosterone was lower with the sports drink (602.33±18.68 pmol/L) than with water (688.08±29.03 pmol/L) and control (695.25±49.21 pmol/L). Endurance capacity was significantly greater with sports drink (56.53±2.53 min) than with water (51.16±1.80 min, p=0.001) and the control (50.09±3.00 min, p=0.001), without differences between the water and control trials (p=0.178). In conclusion, the ingestion of isotonic sports drink increases endurance capacity and maintains aldosterone more effectively than with or without water probably due to improved fluid retention.
... Consumption of a sports drink will provide a large amount of water in addition to other components which could otherwise be obtained from food. The majority of mainstream sports drinks have a carbohydrate content close to 6% weight/ volume and contain small amounts of electrolytes, the main one being sodium (Shirreffs, 2009). Sport drinks are ubiquitous within the recreational and competitive fitness and sporting world. ...
The aim of the study is to formulate sports drinks using fruit juices and tender coconut water and to test their organoleptic acceptability. Sports drinks were developed using sweet lime juice (F1), lime juice (F2), pineapple juice (F3) and tender coconut water (F4) blended with honey, salt and water. The prepared sports drinks were calculated for their nutrient content and organoleptically evaluated using a 5 point hedonic scale. The energy content of F4 was the highest (68.3 Kcal/100 ml), followed by F1 (65.35 Kcal/100 ml) and F3 had the lowest value of 54.9 Kcal/100 ml. The iron content of F3 was the highest (1.2 mg %). The amount of sodium and potassium of F1 was high (237.1 and 245.78 mg %) and almost equal in quantity. The sodium content of F3 was highest (301.05 mg %) followed by F4 (289.6 mg %) and F2 (473.8 mg %). The potassium content of F3 was the least (47.38 mg %), while that of F2 and F4 was 140.19 mg % and 128.69 mg % respectively. The mean scores obtained for overall acceptability was 3.5±0.7, 3.1±0.7, 4.2±0.6 and 4.6±0.5 for F1, F2, F3, F4 respectively. F3 and F4 obtained a mean score of more than 4.0 for taste and overall acceptability. Results of ANOVA indicate no significant difference for colour, appearance and flavour (p≥0.05) between the four variants whereas it was significant for texture, taste and overall acceptability (p≤0.05). The formulated sports drinks contribute to the nutrient requirement of the athletes. On comparing the costs of all the formulated sports drinks, F4 (sports drink made from tender coconut water) was found to be more cost effective and had less food wastage. It may be concluded that sports drink prepared with tender coconut water (F4) being highly acceptable and cost effective can be recommended for athletes for optimal performance.
... adalah faktor yang paling berpengaruh terhadap keringat yang hilang 18,19 . ...
Dehidrasi merupakan salah satu tanda dari ketidakseimbangan cairan tubuh. Status hidrasi penduduk indonesia yaitu 49,2% penduduk tidak terhidrasi dengan baik. Salah satu kelompok yang berisiko tinggi terhadap dehidrasi adalah petani garam. Tujuan penelitian ini untuk menganalisis faktor-faktor risiko dehidrasi pada petani garam yaitu faktor pengetahuan, faktor aktivitas fisik, faktor asupan cairan, dan faktor alat pelindung diri terhadap kejadian dehidrasi. Jenis penelitian ini bersifat observasional analitik dengan desain studi cross sectional. Jumlah subjek pada penelitian ini sebanyak 100 yang dipilih dengan teknik simple random sampling. Hasil analisis menunjukan bahwa pengetahuan, dan aktivitas fisik bukan merupakan faktor risiko dehidrasi pada petani garam. Variabel asupan cairan masih belum menunjukan bukti yang kuat sebagai faktor risiko dehidrasi pada petani garam (POR=3,1; 95%CI=0,3-31,1), tetapi proporsi responden yang mangalami dehidrasi pada kategori asupan cairan defisit(51%) lebih besar daripada responden pada kategori asupan cairan cukup(25%). Selain itu, penggunaan APD yang buruk pada petani garam berisiko 2,4 kali lebih besar untuk mengalami dehidrasi (POR=2,4; 95%CI=1,1-5,5). Petani garam di Kecamatan Kaliori disarankan untuk meningkatkan jumlah konsumsi cairan dan menggunakan APD yang sesuai standar untuk mencegah dehidrasi.
... The volume and composition of ingested drinks are the main factors affecting post-exercise rehydration (Evans, James, Shirreffs, & Maughan, 2017;Shirreffs & Sawka, 2011). Commercially available sports drinks are more effective for rehydration than plain water because they contain water, carbohydrates (CHO) and electrolytes (Na + , K + , etc.), all of which are important for fluid balance in the body (Shirreffs, 2009;Wong & Chen, 2011). ...
The purpose of this study was to examine the effects of different amounts of whey protein in carbohydrate–electrolyte (CE) drinks on post-exercise rehydration. Ten males completed 5 trials in a randomised cross-over design. A 4-h recovery was applied after a 60-min run at 65% VO2peak in each trial. During recovery, the participants ingested a high-carbohydrate CE drink (CE-H), a low-carbohydrate CE drink (CE-L), a high-whey-protein (33 g·L⁻¹) CE drink (CW-H), a medium-whey-protein (22 g·L⁻¹) CE drink (CW-M) or a low-whey-protein (15 g·L⁻¹) CE drink (CW-L) in a volume equivalent to 150% of their body mass (BM) loss. The drinks were provided in six equal boluses and consumed by the participants within 150 min in each trial. After exercise, a BM loss of 2.15% ± 0.05% was achieved. Urine production was less in the CW-M and CW-H trials during recovery, which induced a greater fluid retention in the CW-M (51.0% ± 5.7%) and CW-H (55.4% ± 3.8%) trials than in any other trial (p < .05). The plasma albumin content was higher in the CW-H trial than in the CE-H and CE-L trials at 2 h (p < .05) and 3 h (p < .01) during recovery. The aldosterone concentration was lower in the CE-H trial than in the CW-M and CW-H trials after recovery (p < .05). It is concluded that the rehydration was improved when whey protein was co-ingested with CE drinks during a 4-h recovery after a 60-min run. However, this additive effect was only observed when whey protein concentration was at least 22 g·L⁻¹ in the current study.
The sensation of thirstiness is the desire to drink water. In certain situations, the ingestion of liquid water can be restricted. As a result, thirstiness is not relieved, resulting in an uncomfortable and distressing situation. The present review describes thirstiness and hydration, the food products and beverages that cause thirstiness, and the beverages and food products currently available to quench thirstiness in individuals with restricted access to liquid ingestion. It also discusses how to measure the effectiveness of calming thirstiness. To diminish thirstiness distress, different alternatives to liquids are proposed. Individuals with swallowing disorders are given thickened water, individuals with restricted water ingestion are given ice cubes or ice popsicles of different flavors, and sportspeople are given energy gels. However, current beverage solutions seem not to relieve thirst fully, although some stimuli like iced water, flavors (especially lemon and mint), or acids seem to work better than plain stimuli and could be added to existing products. Therefore, there is still a need to incorporate these strategies into beverage and food formulations and to test their effectiveness.
Objective:
There is a high incidence of concussion and frequent utilization of rapid weight loss (RWL) methods among combat sport athletes, yet the apparent similarity in symptoms experienced as a result of a concussion or RWL has not been investigated. This study surveyed combat sports athletes to investigate the differences in symptom onset and recovery between combat sports and evaluated the relationships between concussion and RWL symptoms.
Design:
Cross-sectional study.
Setting:
Data were collected through an online survey.
Participants:
One hundred thirty-two (115 male athletes and 17 female athletes) combat sport athletes.
Interventions:
Modified Sport Concussion Assessment Tool (SCAT) symptom checklist and weight-cutting questionnaire.
Main outcome measures:
Survey items included combat sport discipline, weight loss, medical history, weight-cutting questionnaire, and concussion and weight-cutting symptom checklists.
Results:
Strong associations (rs = 0.6-0.7, P < 0.05) were observed between concussion and RWL symptoms. The most frequently reported symptom resolution times were 24 to 48 hours for a weight cut (WC; 59%) and 3 to 5 days for a concussion (43%), with 60% to 70% of athletes reporting a deterioration and lengthening of concussion symptoms when undergoing a WC. Most of the athletes (65%) also reported at least one WC in their career to "not go according to plan," resulting in a lack of energy (83%) and strength/power (70%).
Conclusions:
Rapid weight loss and concussion symptoms are strongly associated, with most of the athletes reporting a deterioration of concussion symptoms during a WC. The results indicate that concussion symptoms should be monitored alongside hydration status to avoid any compound effects of prior RWL on the interpretation of concussion assessments and to avoid potential misdiagnoses among combat athletes.
Atletska gibanja izvorni su oblici kretanja s najizraženijom filogenetskom komponentom u kojoj su se kao fundamentalna generička motorička znanja održala od postanka čovjeka do danas (Burton, 1998). Opće je poznata uzrečica kako je atletika “kraljica sportova”. Neizbježan faktor koji se veže uz atletiku je hidracija. Naime, voda čini 60% tijela zrelog muškarca, kod beba i male djece ta je količina 80%, a kod žena 55% (Roganović, 2011). Potrebe za vodom su individualne i razlikuju se od osobe do osobe, te stoga ne možemo utvrditi jedan univerzalni plan unosa tekućine za sve ljude. U ovom radu nastojat će se utvrditi razlike u stanju hidriranosti trkača na srednje i duge pruge, razlike u motivacijskim profilima te povezanost stanja hidriranosti i motivacije.
Purpose The purpose of this study was to confirm and evaluate the assessment of dehydration, whole body sweat rate, sweat sodium · potassium concentration, and fluid intake during workout in college badminton and rugby athletes using the field sweat test. Methods 14 male badminton athletes and 17 male rugby athletes were measured during an usual training session in a typical environment. USG(urine specific gravity) was measured before the start of training. Whole body sweat rate, sweat sodium·potassium concentration, and fluid intake were measured during and post a session of training. Results USG higher than 1.023 in both groups, which was considered as dehydrated. Sweating rate were 1.037±0.315L/h for the badminton athletes and 1.987±0.386L/h for the rugby athletes. The concentration of sodium and potassium were 53.6±20.2mmol/L, 4.1±0.7mmol/L for badminton athletes, and 55.6±15.2mmol/L, 4.3±0.5mmol/L for rugby athletes, respectively. The loss of sodium and potassium were 1.02±0.48g, 0.08±0.02g for badminton athletes, and 1.95±0.52g, 0.15±0.03g for rugby athletes, respectively. Conclusions In this study, a standard protocol of field sweat test was suggested as a useful factor in evaluating athletes' hydration status and electrolyte loss during a routine in-door or out-door training session. And, it is expected to build reliable data to establish a standard hydration guideline for Korean athletes.
Dehydration during exercise has been shown to limit performance. This study aimed to determine the best hydrocolloid for producing sports energy gel from chia seeds (Salvia hispanica L.). This study was a completed random-design study using one factor: the addition of 0.1% w/w hydrocolloids (SEG1: xanthan gum; SEG2: pectin; and SEG3: carboxymethyl cellulose). A sports energy gel was then analyzed for pH, viscosity, total soluble solids, potassium content, and gross energy. The sensory characteristics that were analyzed include color, texture, aroma, and flavor, using hedonic tests on 25 panelists. The addition of different hydrocolloids resulted in significant differences in pH, viscosity, total soluble solids, potassium, and energy contents (p = 0.026; 0.0001; 0.0001; and 0.0001). Differences in hydrocolloid types also led to differences in the panelists’ perceptions of the sports energy gels’ colors and textures (p = 0.008 and 0.0001). The best formulation was the sports energy gel with added xanthan gum, which showed the highest average energy, total soluble solids, potassium, and viscosity values, and the lowest average of pH values (60.24 ± 0.340, 10.6 ± 0.08, 19.6 ± 0.23, 367.4 ± 9.81, and 5.2 ± 0.38, respectively). The conclusion is that chia seeds can be used as the main ingredient for producing a high-energy sports gel. Energy has a huge impact on a person’s physical and mental health.
This study examined the dose-response effects of ingesting different sodium concentrations on markers of hydration and tennis skill. Twelve British nationally-ranked tennis players (age: 21.5 ± 3.1 years; VO 2peak : 45.5 ± 4.4 ml. kg. min −1) completed four identical indoor tennis training sessions in a cluster randomized, single-blind, placebo-controlled, crossover design. Twenty-minutes prior to each training session, participants consumed a 250 ml sodium-containing beverage (10, 20, 50 mmol/L) or a placebo (0 mmol/L), and continued to consume 1,000 ml of the same beverage at set periods during the 1-h training session. Tennis groundstroke and serve performance, agility, urine osmolality, fluid loss, sodium sweat loss and perceptual responses (rating of perceived exertion (RPE), thirst, and gastrointestinal (GI) discomfort) were assessed. Results showed that ingesting 50 mmol/L sodium reduced urine osmolality (−119 mOsmol/kg; p = 0.037) and improved groundstroke performance (5.4; p < 0.001) compared with placebo. This was associated with a reduction in RPE (−0.42; p = 0.029), perception of thirst (−0.58; p = 0.012), and GI discomfort (−0.55; p = 0.019) during the 50 mmol/L trial compared with placebo. Linear trend analysis showed that ingesting greater concentrations of sodium proportionately reduced urine osmolality (β = −147 mOsmol/kg; p = 0.007) and improved groundstroke performance (β = 5.6; p < 0.001) in a dose response manner. Perceived thirst also decreased linearly as sodium concentration increased (β = −0.51; p = 0.044). There was no evidence for an effect of sodium consumption on fluid loss, sweat sodium loss, serve or agility performance (p > 0.05). In conclusion, consuming 50 mmol/L of sodium before and during a 1-h tennis training session reduced urine osmolality and improved groundstroke performance in nationally-ranked tennis players. There was also evidence of dose response effects, showing that ingesting greater sodium concentrations resulted in greater improvements in groundstroke performance. Munson et al. Sodium Ingestion Improves Tennis Skill The enhancement in tennis skill may have resulted from an attenuation of symptomologic distracters associated with hypohydration, such as RPE, thirst and GI discomfort.
New findings:
What is the central question of this study? What are the effects of isomaltulose, an ingredient in carbohydrate-electrolyte beverages to maintain glycaemia and attenuate the risk of dehydration during exercise heat stress, on postexercise rehydration and physiological heat loss responses? What is the main finding and its importance? Consumption of a 6.5% isomaltulose-electrolyte beverage following exercise heat stress restored hydration following a 2 h recovery as compared to a 2% solution or water only. While the 6.5% isomaltulose-electrolytes increased plasma volume and plasma osmolality, which are known to modulate postexercise heat loss, sweating and cutaneous vascular responses did not differ between conditions. Consequently, ingestion beverages containing 6.5% isomaltulose-electrolytes enhanced postexercise rehydration without affecting heat loss responses.
Abstract:
Isomaltulose is a disaccharide carbohydrate widely used during exercise to maintain glycaemia and hydration. We investigated the effects of ingesting a beverage containing isomaltulose and electrolytes on postexercise hydration state and physiological heat loss responses. In a randomized, single-blind cross-over design, 10 young healthy men were hypohydrated by performing up to three 30 min successive moderate-intensity (50% heart rate reserve) bouts of cycling, each separated by 10 min, while wearing a water-perfusion suit heated to 45°C. The protocol continued until a 2% reduction in body mass was achieved. Thereafter, participants performed a final 15 min moderate-intensity exercise bout followed by a 2 h recovery. Following cessation of exercise, participants ingested a beverage consisting of (i) water only (Water), (ii) 2% isomaltulose (CHO-2%), or (iii) 6.5% isomaltulose (CHO-6.5%) equal to the volume of 2% body mass loss within the first 30 min of the recovery. Changes in plasma volume (ΔPV) after fluid ingestion were greater for CHO-6.5% compared with CHO-2% (120 min postexercise) and Water (90 and 120 min) (all P ≤ 0.040). Plasma osmolality remained elevated with CHO-6.5% compared with consumption of the other beverages at 30 and 90 min postexercise (all P ≤ 0.050). Urine output tended to be reduced with CHO-6.5% compared to other fluid conditions (main effect, P = 0.069). Rectal and mean skin temperatures, chest sweat rate and cutaneous perfusion did not differ between conditions (all P > 0.05). In conclusion, compared with CHO-2% and Water, consuming a beverage consisting of CHO-6.5% and electrolytes during recovery under heat stress enhances PV recovery without modulating physiological heat loss responses.
Background and Objective: Rapid and adequate rehydration is important for many athletes, especially those taking multiple sessions of exercise each day, or those involved in weight category sports. The macro nutrient and electrolyte concentration of the fluid ingested following exercise can affect the amount retained within the body can influence hydration status. This study was done to compare the effect of milk consumption on healthy young men rehydration and endurance performance after dehydration due to intermittent exercise in warm environmental condition.
Methods: In this quasi-experimental study, the laboratory protocol was carried out by ten young healthy men in three sessions within one week intervals. Participants were on drinking regiment including water, low-fat milk, and powerade. Urine samples were collected pre-exercise, post-exercise, post-drinking and 1, 2 and 3 hours over recovery. Exercise capacity test commenced within 10 min after 3h recovery. This was undertaken in warm environmental condition at a power output corresponding to 70% VO2 max. Exercise continued until voluntary exhaustion. Heart rate and RPE were recorded at 5 min intervals throughout exercise.
Results: Pre-exercise urine specific gravity value was not different between the milk and the, powerade and the water groups. Total urine output was significantly reduced in the milk group in compared to powerade and the water consumption (P<0.05). At the end of the study, net fluid balance was significantly positive in milk group compared to powerade and water groups (P<0.05). Time of exhaustion on the exercise capacity test (70% VO2 max) was significantly more in milk in comparison with powerade group (P<0.05).
Conclusion: Low-fat milk is more effective at rehydrating compared to water and exercise capacity in intermittent activity of heat in healthy young men.
Keywords: Endurance performance, Dehydration, Rehydration, Milk, Powerade
To investigate the effect of drink temperature on cycling capacity in the heat.
On two separate trials, eight males cycled at 66 +/- 2% VO2peak (mean +/- SD) to exhaustion in hot (35.0 +/- 0.2 degrees C) and humid (60 +/- 1%) environments. Participants ingested three 300-mL aliquots of either a cold (4 degrees C) or a warm (37 degrees C) drink during 30 min of seated rest before exercise and 100 mL of the same drink every 10 min during exercise. Rectal and skin temperatures, heart rate, and sweat rate were recorded. Ratings of thermal sensation and perceived exertion were assessed.
Exercise time was longer (P < 0.001) with the cold drink (63.8 +/- 4.3 min) than with the warm drink (52.0 +/- 4.1 min). Rectal temperature fell by 0.5 +/- 0.1 degrees C (P < 0.001) at the end of the resting period after ingestion of the cold drinks. There was no effect of drink temperature on mean skin temperature at rest (P = 0.870), but mean skin temperature was lower from 20 min during exercise with ingestion of the cold drink than with the warm drink (P < 0.05). Heart rate was lower before exercise and for the first 35 min of exercise with ingestion of the cold drink than with the warm drink (P < 0.05). Drink temperature influenced sweat rate (1.22 +/- 0.34 and 1.40 +/- 0.41 L x h(-1) for the cold and the warm drink, respectively; P < 0.05). Ratings of thermal sensation and perceived exertion (P < 0.01) during exercise were lower when the cold drink was ingested.
Compared with a drink at 37 degrees C, the ingestion of a cold drink before and during exercise in the heat reduced physiological strain (reduced heat accumulation) during exercise, leading to an improved endurance capacity (23 +/- 6%).
This study examined effects of ingesting a 10% carbohydrate (CHO) drink (CI) or placebo (PI) at 500 ml/h on total (splanchnic) glucose appearance (endogenous+exogenous; Ra), blood glucose oxidation, and muscle glycogen utilization in 14 male endurance-trained cyclists who rode for 180 min at 70% of maximal O2 uptake after CHO loading [starting muscle glycogen 203 +/- 7 (SE) mmol/kg wet wt]. Total CHO oxidation was similar in CI and PI, but Ra increased significantly during the trial in both groups with CI reaching a plateau after 75 min. Ra was significantly greater in CI than in PI at the end of exercise. Blood glucose oxidation also increased significantly during the trial to a plateau in CI and was significantly higher in CI than in PI at the end of exercise. However, mean endogenous Ra was significantly lower in CI than in PI throughout exercise, as was oxidation of endogenous blood glucose, which remained almost constant in CI and reached 43 +/- 8 and 73 +/- 13 mumol.min-1.kg fat-free mass-1 in CI and PI, respectively, at the end of exercise. At 0.83 g/min of CHO ingestion, 0.77 +/- 0.03 g/min was oxidized. Muscle glycogen utilization was identical in both groups and was higher during the 1st h of exercise.(ABSTRACT TRUNCATED AT 250 WORDS)
Dehydration alters cardiovascular, thermoregulatory, central nervous system, and metabolic functions. One or more of these alterations will degrade endurance exercise performance when dehydration exceeds 2% of body weight. These performance decrements are accentuated by heat stress. To minimize the adverse consequences of body water deficits on endurance exercise performance, it is recommended that fluid intake be sufficient to minimize dehydration to less than 2% of body weight loss. This can usually be achieved with fluid intakes of under 1 L x h(-1).
The high metabolic rates sustained by soccer players during training and match-play cause sweat to be produced in both warm and temperate environments. There is limited published information available on the effects of this sweat loss on performance in soccer. However, this limited information, together with knowledge of the effects of sweat loss in other sports with skill components as well as endurance and sprint components, suggests that the effects of sweating will be similar to the effects in these other activities. Therefore, the generalization that a body mass reduction equivalent to 2% should be the acceptable limit of sweat losses seems reasonable. This amount, or more, of sweat loss reflected in body mass loss is a common experience for some players. Sodium is the main electrolyte lost in sweat and the available data indicate considerable variability in sodium losses between players due to differences in sweating rate and sweat electrolyte concentration. Additionally, the extent of sodium loss is such that its replacement will be warranted for some of these players during training sessions and matches. Although soccer is a team sport, the great individual variability in sweat and electrolyte losses of players in the same training session or match dictates that individual monitoring to determine individual water and electrolyte requirements should be an essential part of a player's nutritional strategy.
Nine males cycled at 53% (s = 2) of their peak oxygen uptake (VO(2peak)) for 90 min (dry bulb temperature: 25.4 degrees C, s = 0.2; relative humidity: 61%, s = 3). One litre of flavoured water at 10 (cold), 37 (warm) or 50 degrees C (hot) was ingested 30 - 40 min into exercise. Immediately after the 90 min of exercise, participants cycled at 95%VO(2peak) to exhaustion to assess exercise capacity. Rectal and mean skin temperatures and heart rate were recorded. The gradient of rise in rectal temperature was influenced (P < 0.01) by drink temperature. Mean skin temperature was highest in the hot trial (cold trial: 34.2 degrees C, s = 0.5; warm trial: 34.4 degrees C, s = 0.5; hot trial: 34.7 degrees C, s = 0.6; P < 0.01). Significant differences were observed in heart rate (cold trial: 132 beats . min(-1), s = 13; warm trial: 134 beats . min(-1), s = 12; hot trial: 139 beats . min(-1), s = 13; P < 0.05). Exercise capacity was similar between trials (cold trial: 234 s, s = 69; warm trial: 214 s, s = 52; hot trial: 203 s, s = 53; P = 0.562). The heat load and debt induced via drinking resulted in appropriate thermoregulatory reflexes during exercise leading to an observed heat content difference of only 33 kJ instead of the predicted 167 kJ between the cold and hot trials. These results suggest that there may be a role for drink temperature in influencing thermoregulation during exercise.
Significant scientific evidence documents the deleterious effects of hypohydration (reduced total body water) on endurance exercise performance; however, the influence of hypohydration on muscular strength, power and high-intensity endurance (maximal activities lasting >30 seconds but <2 minutes) is poorly understood due to the inconsistent results produced by previous investigations. Several subtle methodological choices that exacerbate or attenuate the apparent effects of hypohydration explain much of this variability. After accounting for these factors, hypohydration appears to consistently attenuate strength (by approximately 2%), power (by approximately 3%) and high-intensity endurance (by approximately 10%), suggesting alterations in total body water affect some aspect of force generation. Unfortunately, the relationships between performance decrement and crucial variables such as mode, degree and rate of water loss remain unclear due to a lack of suitably uninfluenced data. The physiological demands of strength, power and high-intensity endurance couple with a lack of scientific support to argue against previous hypotheses that suggest alterations in cardiovascular, metabolic and/or buffering function represent the performance-reducing mechanism of hypohydration. On the other hand, hypohydration might directly affect some component of the neuromuscular system, but this possibility awaits thorough evaluation. A critical review of the available literature suggests hypohydration limits strength, power and high-intensity endurance and, therefore, is an important factor to consider when attempting to maximise muscular performance in athletic, military and industrial settings.
In this study, we examined thermoregulatory responses to ingestion of separate aliquots of drinks at different temperatures during low-intensity exercise in conditions of moderate heat stress. Eight men cycled at 50% (s = 3) of their peak oxygen uptake (VO2peak) for 90 min (dry bulb temperature: 25.3 degrees C, s = 0.5; relative humidity: 60%, s = 5). Four 400-ml aliquots of flavoured water at 10 degrees C (cold), 37 degrees C (warm) or 50 degrees C (hot) were ingested after 30, 45, 60, and 75 min of exercise. Immediately after the 90 min of exercise, participants cycled at 95% VO2peak to exhaustion to assess exercise capacity. There were no differences between trials in rectal temperature at the end of the 90 min of exercise (cold: 38.11 degrees C, s = 0.30; warm: 38.10 degrees C, s = 0.33; hot: 38.21 degrees C, s = 0.30; P = 0.765). Mean skin temperature between 30 and 90 min tended to be influenced by drink temperature (cold: 34.49 degrees C, s = 0.64; warm: 34.53 degrees C, s = 0.69; hot: 34.71 degrees C, s = 0.48; P = 0.091). Mean heart rate from 30 to 90 min was higher in the hot trial (129 beats . min(-1), s = 7; P < 0.05) than on the cold (124 beats . min(-1), s = 9) and warm trials (126 beats . min(-1), s = 8). Ratings of thermal sensation were higher on the hot trial than on the cold trial at 35 and 50 min (P < 0.05). Exercise capacity was similar between trials (P = 0.963). The heat load and debt induced by periodic drinking resulted in similar body temperatures during low-intensity exercise in conditions of moderate heat stress due to appropriate thermoregulatory reflexes.
This study assessed whether replacing sweat losses with sodium-free fluid can lower the plasma sodium concentration and thereby precipitate the development of hyponatremia. Ten male endurance athletes participated in one 1-h exercise pretrial to estimate fluid needs and two 3-h experimental trials on a cycle ergometer at 55% of maximum O 2 consumption at 34°C and 65% relative humidity. In the experimental trials, fluid loss was replaced by distilled water (W) or a sodium-containing (18 mmol/l) sports drink, Gatorade (G). Six subjects did not complete 3 h in trial W, and four did not complete 3 h in trial G. The rate of change in plasma sodium concentration in all subjects, regardless of exercise time completed, was greater with W than with G (−2.48 ± 2.25 vs. −0.86 ± 1.61 mmol ⋅ l ⁻¹ ⋅ h ⁻¹ , P = 0.0198). One subject developed hyponatremia (plasma sodium 128 mmol/l) at exhaustion (2.5 h) in the W trial. A decrease in sodium concentration was correlated with decreased exercise time ( R = 0.674; P = 0.022). A lower rate of urine production correlated with a greater rate of sodium decrease ( R = −0.478; P = 0.0447). Sweat production was not significantly correlated with plasma sodium reduction. The results show that decreased plasma sodium concentration can result from replacement of sweat losses with plain W, when sweat losses are large, and can precipitate the development of hyponatremia, particularly in individuals who have a decreased urine production during exercise. Exercise performance is also reduced with a decrease in plasma sodium concentration. We, therefore, recommend consumption of a sodium-containing beverage to compensate for large sweat losses incurred during exercise.
Six well-trained men (peak pulmonary oxygen uptake = 5.03 +/- 0.11 l/min) were studied during 2 h of exercise at 69 +/- 1% peak pulmonary oxygen uptake to examine the effect of carbohydrate (CHO) ingestion on glucose kinetics. Subjects ingested 250 ml of either a 10% glucose solution containing 6-[3H]glucose (CHO) or a sweet placebo every 15 min during exercise. Glucose kinetics were assessed by 6,6-[2H]glucose infusion corrected for gut-derived glucose in CHO. Plasma glucose was higher (P < 0.05) in CHO from 20 min. Total glucose appearance was higher in CHO due to glucose delivery from the gut (68 +/- 7 g), since hepatic glucose production was reduced by 51% (29 +/- 5 vs. 59 +/- 5 g). Glucose uptake was higher in CHO (96 +/- 7 vs. 60 +/- 6 g) with the ingested glucose supplying 67 +/- 4 g and, with the assumption that it was fully oxidized, accounted for 14 +/- 1% of total energy expenditure. In conclusion, CHO ingestion during prolonged exercise results in suppression of hepatic glucose production and increased glucose uptake. These effects appear to be mediated mainly by increased plasma glucose and insulin levels.
Four athletes developed water intoxication (hyponatremia) during endurance events lasting more than 7 h. The etiology of the condition appears to be voluntary hyperhydration with hypotonic solutions combined with moderate sweat sodium chloride losses. The reason why the fluid excess in these runners was not corrected by increased urinary losses is unknown. When advised to drink less during prolonged exercise, three of the athletes have subsequently completed prolonged endurance events uneventfully. (C)1985The American College of Sports Medicine
Significant scientific evidence documents the deleterious effects of hypohydration (reduced total body water) on endurance exercise performance; however, the influence of hypohydration on muscular strength, power and high-intensity endurance (maximal activities lasting >30 seconds but <2 minutes) is poorly understood due to the inconsistent results produced by previous investigations. Several subtle methodological choices that exacerbate or attenuate the apparent effects of hypohydration explain much of this variability. After accounting for these factors, hypohydration appears to consistently attenuate strength (by ≈2%), power (by ≈3%) and high-intensity endurance (by ∼10%), suggesting alterations in total body water affect some aspect of force generation. Unfortunately, the relationships between performance decrement and crucial variables such as mode, degree and rate of water loss remain unclear due to a lack of suitably uninfluenced data. The physiological demands of strength, power and high-intensity endurance couple with a lack of scientific support to argue against previous hypotheses that suggest alterations in cardiovascular, metabolic and/or buffering function represent the performance-reducing mechanism of hypohydration. On the other hand, hypohydration might directly affect some component of the neuromuscular system, but this possibility awaits thorough evaluation. A critical review of the available literature suggests hypohydration limits strength, power and highintensity endurance and, therefore, is an important factor to consider when attempting to maximise muscular performance in athletic, military and industrial settings.
The effectiveness of different carbohydrate solutions in restoring fluid balance in situations of voluntary fluid intake has not been examined previously. The effect of the carbohydrate content of drinks ingested after exercise was examined in 6 males and 3 females previously dehydrated by 1.99 +/- 0.07% of body mass via intermittent exercise in the heat. Beginning 30 min after the cessation of exercise, subjects drank ad libitum for a period of 120 min. Drinks contained 31 mmol.L-1 Na+ as NaCl and either 0%, 2%, or 10% glucose with mean +/- SD osmolalities of 74 +/- 1, 188 +/- 3, and 654 +/- 4 mosm.kg-1, respectively. Blood and urine samples were collected before and after exercise, midway through rehydration, and throughout a 5 h recovery period. Total fluid intake was not different among trials (0%: 2258 +/- 519 mL; 2%: 2539 +/- 436 mL; 10%: 2173 +/- 252 mL; p = 0.173). Urine output was also not different among trials (p = 0.160). No differences among trials were observed in net fluid balance or in the fraction of the ingested drink retained. In conclusion, in situations of voluntary fluid intake, hypertonic carbohydrate-electrolyte solutions are as effective as hypotonic carbohydrate-electrolyte solutions at restoring whole-body fluid balance.
This study investigated the effect of the osmolality and carbohydrate content of drinks on their rehydration effectiveness after exercise-induced dehydration.
Six healthy male volunteers were dehydrated by 1.9+/-0.1% of body mass by intermittent cycle ergometer exercise in the heat before ingesting one of three solutions with different carbohydrate contents and osmolalities over a period of 1h. Thirty minutes after the cessation of exercise, subjects drank a volume that amounted to 150% (130-150, median [range]) of their body mass loss. Drinks contained 25 mmol/L Na(+) and 0%, 2%, or 10% glucose with osmolalities of (mean+/-SD) 79+/-4, 193+/-5, and 667+/-12 mosm/kg, respectively. Blood and urine samples were collected before exercise, after exercise, and 0, 1, 2, 3, 4, and 6h after the end of the rehydration period.
Significantly more of the ingested fluid was retained in the 10% trial (46+/-9%) than in the 0% trial (27+/-13%), with 40+/-14% retained in the 2% trial. Subjects remained euhydrated for 1h longer in the 10% glucose trial than in the 2% glucose trial. In the 2% glucose trial, plasma volume was elevated immediately after and 1h after rehydration.
This study suggests that, following the rehydration protocol used, hypertonic glucose-sodium drinks may be more effective at restoring and maintaining hydration status after sweat loss than more dilute solutions when the sodium concentration is comparable.
The change in blood and plasma volume following ingestion of glucose solutions of varying concentrations was estimated in twelve healthy male volunteers. Subjects consumed, within a 5 min period, 600 ml of a solution containing 0, 2, 5 or 10 % glucose with osmolalities of 0 (sd 0), 111 (sd 1), 266 (sd 7) and 565 (sd 5) mOsm/kg, respectively. Blood samples were collected over the course of 1 h after ingestion at intervals of 10 min. After ingestion of the 2 % glucose solution, plasma volume increased from baseline levels at 20 min. Plasma volume decreased from baseline levels at 10 and 60 min after ingestion of the 10 % glucose solution. Heart rate was elevated at 10 and 60 min after ingestion of the 10 % glucose solution and decreased at 30 and 40 min after ingestion of the 2 % glucose solution relative to the average heart rate recorded before drinking. It is concluded that ingestion of hypertonic, energy-dense glucose solutions results in a decrease in plasma and extracellular fluid volume, most likely due to the net secretion of water into the intestinal lumen.
The purpose of this experiment was to determine whether fluid ingestion attenuates the hyperthermia and cardiovascular drift that occurs during exercise dehydration due to increases in blood volume. In addition, forearm blood flow, which is indicative of skin blood flow, was measured to determine whether the attenuation of hyperthermia and cardiovascular drift during exercise with fluid ingestion is due to higher skin blood flow. On three different occasions, seven trained cyclists [mean age, body weight, and maximum oxygen uptake: 23 +/- 3 yr, 73.9 +/- 10.5 kg, and 4.75 +/- 0.34 (SD) l/min, respectively] cycled at a power output equal to 62-67% maximum oxygen uptake for 2 h in a warm environment (33 degrees C, 50% relative humidity, wind speed 2.5 m/s). During exercise, they randomly received no fluid (NF) or a volume of a carbohydrate-electrolyte fluid replacement solution (FR) sufficient to replace 80 +/- 2% of sweat loss or were intravenously infused with 5.3 ml/kg of a blood volume expander (BVX; 6% dextran in saline). The infusion of 398 +/- 23 ml of BVX maintained blood volume at levels similar to that when 2,404 +/- 103 ml of fluid were ingested during FR and greater than that when no fluid was ingested during the 2nd h of exercise (P less than 0.05). However, BVX and NF resulted in similar esophageal and rectal temperatures, forearm blood flow, and elevations in serum osmolality and sodium concentration during 2 h of exercise.(ABSTRACT TRUNCATED AT 250 WORDS)
This investigation determined the effect of different rates of dehydration, induced by ingesting different volumes of fluid during prolonged exercise, on hyperthermia, heart rate (HR), and stroke volume (SV). On four different occasions, eight endurance-trained cyclists [age 23 +/- 3 (SD) yr, body wt 71.9 +/- 11.6 kg, maximal O2 consumption 4.72 +/- 0.33 l/min] cycled at a power output equal to 62-67% maximal O2 consumption for 2 h in a warm environment (33 degrees C dry bulb, 50% relative humidity, wind speed 2.5 m/s). During exercise, they randomly received no fluid (NF) or ingested a small (SF), moderate (MF), or large (LF) volume of fluid that replaced 20 +/- 1, 48 +/- 1, and 81 +/- 2%, respectively, of the fluid lost in sweat during exercise. The protocol resulted in graded magnitudes of dehydration as body weight declined 4.2 +/- 0.1, 3.4 +/- 0.1, 2.3 +/- 0.1, and 1.1 +/- 0.1%, respectively, during NF, SF, MF, and LF. After 2 h of exercise, esophageal temperature (Tes), HR, and SV were significantly different among the four trials (P < 0.05), with the exception of NF and SF. The magnitude of dehydration accrued after 2 h of exercise in the four trials was linearly related with the increase in Tes (r = 0.98, P < 0.02), the increase in HR (r = 0.99, P < 0.01), and the decline in SV (r = 0.99, P < 0.01). LF attenuated hyperthermia, apparently because of higher skin blood flow, inasmuch as forearm blood flow was 20-22% higher than during SF and NF at 105 min (P < 0.05). There were no differences in sweat rate among the four trials. In each subject, the increase in Tes from 20 to 120 min of exercise was highly correlated to the increase in serum osmolality (r = 0.81-0.98, P < 0.02-0.19) and the increase in serum sodium concentration (r = 0.87-0.99, P < 0.01-0.13) from 5 to 120 min of exercise. In summary, the magnitude of increase in core temperature and HR and the decline in SV are graded in proportion to the amount of dehydration accrued during exercise.
This study examined the influence of both hydration and blood glucose concentration on cardiovascular drift during exercise. We first determined if the prevention of dehydration during exercise by full fluid replacement prevents the decline in stroke volume (SV) and cardiac output (CO) during prolonged exercise. On two occasions, 10 endurance-trained subjects cycled an ergometer in a 22 degrees C room for 2 h, beginning at 70 +/- 1% maximal O2 uptake (VO2max) and in a euhydrated state. During one trial, no fluid (NF) replacement was provided and the subject's body weight declined 2.09 +/- 0.19 kg or 2.9%. During the fluid replacement trial (FR), water was ingested at a rate that prevented body weight from declining after 2 h of exercise (i.e., 2.34 +/- 0.17 1/2 h). SV declined 15% and CO declined 7% during the 20- to 120-min period of the NF trial while heart rate (HR) increased 10% and O2 uptake (VO2) increased 6% (all P less than 0.05). In contrast, SV was maintained during the 20- to 120-min period of FR while HR increased 5% and thus CO actually increased 7% (all P less than 0.05). Rectal temperature, SV, and HR were similar during the 1st h of exercise during NF and FR. However, after 2 h of exercise, rectal temperature was 0.6 degree C higher (P less than 0.05) and SV and CO were 11-16% lower (P less than 0.05) during NF compared with FR.(ABSTRACT TRUNCATED AT 250 WORDS)
The availability of carbohydrate (CHO) as a substrate for the exercising muscles is known to be a limiting factor in the performance of prolonged cycle exercise, and provision of exogenous CHO in the form of glucose can increase endurance capacity. The present study examined the effects of ingestion of fluids and of CHO in different forms on exercise performance. Six male volunteers exercised to exhaustion on a cycle ergometer at a workload which required approximately 70% of Vo2max. After one preliminary trial, subjects performed this exercise test on six occasions, one week apart. Immediately before exercise, and at 10-min intervals throughout, subjects ingested 100 ml of one of the following: control (no drink), water, glucose syrup, fructose syrup, glucose-fructose syrup or a dilute glucose-electrolyte solution. Each of the syrup solutions contained approximately 36 g CHO per 100 ml; the isotonic glucose-electrolyte solution contained 4 g glucose per 100 ml. A randomised Latin square order of administration of trials was employed. Expired air samples for determination of Vo2, respiratory exchange ratio and rate of CHO oxidation were collected at 15-min intervals. Venous blood samples were obtained before and after exercise. Subjects drinking the isotonic glucose-electrolyte solution exercised longer (90.8 (12.4) min, mean (SEM] than on the control test (70.2 (8.3) min; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Four athletes developed water intoxication (hyponatremia) during endurance events lasting more than 7 h. The etiology of the condition appears to be voluntary hyperhydration with hypotonic solutions combined with moderate sweat sodium chloride losses. The reason why the fluid excess in these runners was not corrected by increased urinary losses is unknown. When advised to drink less during prolonged exercise, three of the athletes have subsequently completed prolonged endurance events uneventfully.
1. The effect of osmolality and carbohydrate content on the rate of gastric emptying was assessed by using the double sampling gastric aspiration technique to measure the rate of gastric emptying of isoenergetic and isosmotic solutions of glucose and glucose polymer. Six healthy male subjects were each studied on four separate occasions using a test drink volume of 600 ml. 2. The half-emptying time (t1/2, mean +/- S.E.M.) for a dilute (40 g l-1) solution of glucose (LG, 230 mosmol kg-1) was 17 +/- 1 min. This was greater than that (14 +/- 1 min) for a glucose polymer solution with the same energy content (LP, 42 mosmol kg-1). A concentrated (188 g l-1) glucose polymer solution (HP, 237 mosmol kg-1) emptied faster (t1/2 = 64 +/- 8 min) than the corresponding isoenergetic glucose solution (HG, 1300 mosmol kg-1, t1/2 = 130 +/- 18 min). 3. The dilute (40 g l-1) glucose solution emptied faster than the concentrated (188 g l-1) glucose polymer solution with the same osmolality (LG, 230 mosmol kg-1; HP, 237 mosmol kg-1). 4. The two dilute solutions (40 g l-1) delivered a similar amount of carbohydrate to the small intestine, whereas the concentrated (188 g l-1) glucose polymer solution delivered a greater amount of carbohydrate at 20, 40 and 50 min than the isoenergetic glucose solution. 5. These results indicate that both osmolality and carbohydrate content influence gastric emptying of liquids in man, but the carbohydrate content appears to have greater influence than osmolality.(ABSTRACT TRUNCATED AT 250 WORDS)
This study determined the effects of fluid and carbohydrate ingestion on performance, core temperature, and cardiovascular responses during intense exercise lasting 1 h. On four occasions, eight men cycled at 80 +/- 1% (+/- SEM) of VO2max for 50 min followed by a performance test. During exercise, they consumed either a large volume (1330 +/- 60 ml) of a 6% carbohydrate (79 +/- 4 g) solution or water or a small volume (200 +/- 10 ml) of a 40% maltodextrin (79 +/- 4 g) solution or water. These trials were pooled so the effects of fluid replacement (Large FR vs Small FR) and carbohydrate ingestion (CHO vs NO CHO) could be determined. Performance times were 6.5% faster during Large FR than Small FR and 6.3% faster during CHO than NO CHO (P < 0.05). At 50 min, heart rate was 4 +/- 1 b.min-1 lower and esophageal temperature was 0.33 +/- 0.04 degrees C lower during Large FR than Small FR (P < 0.05) but no differences occurred between CHO and NO CHO. In summary, Large FR slightly attenuates the increase in heart rate and core temperature which occurs during Small FR. Both fluid and carbohydrate ingestion equally improve cycling performance and their effects are additive.
Six well-trained men (peak pulmonary oxygen uptake = 5.03 +/- 0.11 l/min) were studied during 2 h of exercise at 69 +/- 1% peak pulmonary oxygen uptake to examine the effect of carbohydrate (CHO) ingestion on glucose kinetics. Subjects ingested 250 ml of either a 10% glucose solution containing 6-[3H]glucose (CHO) or a sweet placebo every 15 min during exercise. Glucose kinetics were assessed by 6,6-[2H]glucose infusion corrected for gut-derived glucose in CHO. Plasma glucose was higher (P < 0.05) in CHO from 20 min. Total glucose appearance was higher in CHO due to glucose delivery from the gut (68 +/- 7 g), since hepatic glucose production was reduced by 51% (29 +/- 5 vs. 59 +/- 5 g). Glucose uptake was higher in CHO (96 +/- 7 vs. 60 +/- 6 g) with the ingested glucose supplying 67 +/- 4 g and, with the assumption that it was fully oxidized, accounted for 14 +/- 1% of total energy expenditure. In conclusion, CHO ingestion during prolonged exercise results in suppression of hepatic glucose production and increased glucose uptake. These effects appear to be mediated mainly by increased plasma glucose and insulin levels.
A 17-year-old, nationally ranked, male tennis player (AH) had been experiencing heat cramps during tennis match play. His medical history and previous physical exams were unremarkable, and his in-office blood chemistry profiles were normal. On-court evaluation and an analysis of a 3-day dietary record revealed that AH's sweat rate was extensive (2.5 L.hr-1) and that his potential daily on-court sweat sodium losses (89.8 mmol.hr of play-1) could readily exceed his average daily intake of sodium (87.0-174.0 mmol.day-1). The combined effects of excessive and repeated fluid and sodium losses likely predisposed AH to heat cramps during play. AH was ultimately able to eliminate heat cramps during competition and training by increasing his daily dietary intake of sodium.
Sodium and water loss during, and replacement after, exercise-induced volume depletion was investigated in six volunteers volume depleted by 1.89 +/- 0.17% (SD) of body mass by intermittent exercise in a warm, humid environment. Subjects exercised in a large, open plastic bag, allowing collection of all sweat secreted during exercise. For over 60 min beginning 40 min after the end of exercise, subjects ingested drinks containing 0, 25, 50, or 100 mmol/l sodium (trials 0, 25, 50, and 100) in a volume (ml) equivalent to 150% of the mass lost (g) by volume depletion. Body mass loss and sweat electrolyte (Na+, K+, and Cl-) loss were the same on each trial. The measured sweat sodium concentration was 49.2 +/- 18.5 mmol/l, and the total loss (63.9 +/- 38.7 mmol) was greater than that ingested on trials 0 and 25. Urine production over the 6-h recovery period was inversely related to the amount of sodium ingested. Subjects were in whole body negative sodium balance on trials 0 (-104 +/- 48 mmol) and 25 (-65 +/- 30 mmol) and essentially in balance on trial 50 (-13 +/- 29 mmol) but were in positive sodium balance on trial 100 (75 +/- 40 mmol). Only on trial 100 were subjects in positive fluid balance at the end of the study. There was a large urinary loss of potassium over the recovery period on trial 100, despite a negligible intake during volume repletion. These results confirm the importance of replacement of sodium as well as water for volume repletion after sweat loss. The sodium intake on trial 100 was appropriate for acute fluid balance restoration, but its consequences for potassium levels must be considered to be undesirable in terms of whole body electrolyte homeostasis for anything other than the short term.
This study assessed whether replacing sweat losses with sodium-free fluid can lower the plasma sodium concentration and thereby precipitate the development of hyponatremia. Ten male endurance athletes participated in one 1-h exercise pretrial to estimate fluid needs and two 3-h experimental trials on a cycle ergometer at 55% of maximum O2 consumption at 34 degrees C and 65% relative humidity. In the experimental trials, fluid loss was replaced by distilled water (W) or a sodium-containing (18 mmol/l) sports drink, Gatorade (G). Six subjects did not complete 3 h in trial W, and four did not complete 3 h in trial G. The rate of change in plasma sodium concentration in all subjects, regardless of exercise time completed, was greater with W than with G (-2.48 +/- 2.25 vs. -0.86 +/- 1.61 mmol. l-1. h-1, P = 0.0198). One subject developed hyponatremia (plasma sodium 128 mmol/l) at exhaustion (2.5 h) in the W trial. A decrease in sodium concentration was correlated with decreased exercise time (R = 0.674; P = 0.022). A lower rate of urine production correlated with a greater rate of sodium decrease (R = -0. 478; P = 0.0447). Sweat production was not significantly correlated with plasma sodium reduction. The results show that decreased plasma sodium concentration can result from replacement of sweat losses with plain W, when sweat losses are large, and can precipitate the development of hyponatremia, particularly in individuals who have a decreased urine production during exercise. Exercise performance is also reduced with a decrease in plasma sodium concentration. We, therefore, recommend consumption of a sodium-containing beverage to compensate for large sweat losses incurred during exercise.
For a person undertaking regular exercise, any fluid deficit that is incurred during one exercise session can potentially compromise the next exercise session if adequate fluid replacement does not occur. Fluid replacement after exercise can, therefore, frequently be thought of as hydration before the next exercise bout. The importance of ensuring euhydration before exercise and the potential benefits of temporary hyperhydration with sodium salts or glycerol solutions are also important issues. Post-exercise restoration of fluid balance after sweat-induced dehydration avoids the detrimental effects of a body water deficit on physiological function and subsequent exercise performance. For effective restoration of fluid balance, the consumption of a volume of fluid in excess of the sweat loss and replacement of electrolyte, particularly sodium, losses are essential. Intravenous fluid replacement after exercise has been investigated to a lesser extent and its role for fluid replacement in the dehydrated but otherwise well athlete remains equivocal.
The amounts of water, carbohydrate and salt that athletes are advised to ingest during exercise are based upon their effectiveness in attenuating both fatigue as well as illness due to hyperthermia, dehydration or hyperhydration. When possible, fluid should be ingested at rates that most closely match sweating rate. When that is not possible or practical or sufficiently ergogenic, some athletes might tolerate body water losses amounting to 2% of body weight without significant risk to physical well-being or performance when the environment is cold (e.g. 5-10 degrees C) or temperate (e.g. 21-22 degrees C). However, when exercising in a hot environment ( > 30 degrees C), dehydration by 2% of body weight impairs absolute power production and predisposes individuals to heat injury. Fluid should not be ingested at rates in excess of sweating rate and thus body water and weight should not increase during exercise. Fatigue can be reduced by adding carbohydrate to the fluids consumed so that 30-60 g of rapidly absorbed carbohydrate are ingested throughout each hour of an athletic event. Furthermore, sodium should be included in fluids consumed during exercise lasting longer than 2 h or by individuals during any event that stimulates heavy sodium loss (more than 3-4 g of sodium). Athletes do not benefit by ingesting glycerol, amino acids or alleged precursors of neurotransmitter. Ingestion of other substances during exercise, with the possible exception of caffeine, is discouraged. Athletes will benefit the most by tailoring their individual needs for water, carbohydrate and salt to the specific challenges of their sport, especially considering the environment's impact on sweating and heat stress.
Fluid balance and sweat electrolyte losses were measured in the players and substitutes engaged in an English Premier League Reserve competitive football match played at an ambient temperature of 6-8 degrees C (relative humidity 50-60%). Intake of water and/or sports drink and urine output were recorded, and sweat composition was estimated from absorbent swabs applied to 4 skin sites for the duration of the game. Body mass was recorded before and after the game. Data were obtained for 22 players (age 21 y, height 180 cm, mass 78 kg) and 9 substitutes (17 y, 181 cm, 72 kg). All were male. Two of the players were dismissed during the game, and none of the substitutes played any part in the game. Mean +/- SD sweat loss of players amounted to 1.68 +/- 0.40 L, and mean fluid intake was 0.84 +/- 0.47 L (n = 20), with no difference between teams. Corresponding values for substitutes, none of whom played in the match, were 0.40 +/- 0.24 L and 0.78 +/- 0.46 L (n = 9). Prematch urine osmolality was 678 +/- 344 mOsm/kg: 11 of the 31 players provided samples with an osmolality of more than 900 mOsm/kg. Sweat sodium concentration was 62 +/- 13 mmol/L, and total sweat sodium loss during the game was 2.4 +/- 0.8 g. These descriptive data show a large individual variability in hydration status, sweat losses, and drinking behaviors in a competitive football match played in a cool environment, highlighting the need for individualized assessment of hydration status to optimize fluid-replacement strategies.
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