Effects of Nutrition Education Interventions in Team Sport Players. A Systematic Review

Considering nutrition education interventions have been frequently implemented in team sport athletes and have shown promising results, this study aimed to summarize the effects of nutrition education interventions on eating habits, nutrition knowledge, body composition, and physical performance in team sport athletes. A systematic review was conducted using the following databases: PubMed/MEDLINE, Web of Science and SPORTDiscus. A total of 14 studies met the inclusion criteria for the review. The methodological quality of included studies was evaluated, and each study was assessed according to the analyzed variables (i.e., eating habits, nutrition knowledge, body composition, and physical performance). Most studies showed improvements in or maintenance of variables used to indicate eating habits, nutrition knowledge, and body composition. However, limited studies examined the effect of nutrition education interventions on physical performance, with existing studies demonstrating disparate results. These findings suggest implementation of nutrition education interventions in team sport athletes could be an effective strategy to improve their eating habits, nutrition knowledge, and body composition. Due to the heterogeneity across the included studies regarding sport modality, competition level, age, and sex of the athletes investigated, as well as the intervention type adopted (i.e., online or face-to-face), it is difficult to establish optimal nutrition education interventions for each analyzed variable.     

Physician and sports]

The main objective of physical activity should be to achieve the best possible level of physical fitness and thereby psychic wellbeing. This important objective in preventive medicine may be obtained by a well balanced leisure sport program. On the other hand, due to its high demands, modern competition sport or elite sport increasingly results in severe organic damages and therefore therapeutic measures are of more importance. The physician has important functions both in prevention and therapy in all aspects of physical activity. Unfortunately, in Switzerland he is ofter insufficiantly prepared to deal with these functions. Most of the requirements for manipulation of performance that the physician is confronted with are questionable and not compatible with the medical ethics.     

Nutrition for sports performance: issues and opportunities

Diet can significantly influence athletic performance, but recent research developments have substantially changed our understanding of sport and exercise nutrition. Athletes adopt various nutritional strategies in training and competition in the pursuit of success. The aim of training is to promote changes in the structure and function of muscle and other tissues by selective modulation of protein synthesis and breakdown in response to the training stimulus. This process is affected by the availability of essential amino acids in the post-exercise period. Athletes have been encouraged to eat diets high in carbohydrate, but low-carbohydrate diets up-regulate the capacity of muscle for fat oxidation, potentially sparing the limited carbohydrate stores. Such diets, however, do not enhance endurance performance. It is not yet known whether the increased capacity for fat oxidation that results from training in a carbohydrate-deficient state can promote loss of body fat. Preventing excessive fluid deficits will maintain exercise capacity, and ensuring adequate hydration status can also reduce subjective perception of effort. This latter effect may be important in encouraging exercise participation and promoting adherence to exercise programmes. Dietary supplement use is popular in sport, and a few supplements may improve performance in specific exercise tasks. Athletes must be cautious, however, not to contravene the doping regulations. There is an increasing recognition of the role of the brain in determining exercise performance: various nutritional strategies have been proposed, but with limited success. Nutrition strategies developed for use by athletes can also be used to achieve functional benefits in other populations.     

The athlete's diet: nutritional goals and dietary strategies

When talented, motivated and highly trained athletes meet for competition the margin between victory and defeat is usually small. When everything else is equal, nutrition can make the difference between winning and losing. Although the primary concern of many athletes is to supplement the diet with protein, vitamins and minerals, and a range of more exotic compounds, key dietary issues are often neglected. Athletes must establish their nutritional goals, and must also be able to translate them into dietary strategies that will meet these goals. Athletes are often concerned with dietary manipulations in the period around competition, but the main role of nutrition may be to support consistent intensive training which will lead to improved performance. Meeting energy demand and maintaining body mass and body fat at appropriate levels are key goals. An adequate intake of carbohydrate is crucial for maintaining muscle glycogen stores during hard training, but the types of food and the timing of intake are also important. Protein ingestion may stimulate muscle protein synthesis in the post-exercise period, promoting the process of adaptation in the muscles. Restoration of fluid and electrolyte balance after exercise is essential. If energy intake is high and a varied diet is consumed, supplementation of the diet with vitamins and minerals is not warranted, unless a specific deficiency is identified. Specific strategies before competition may be necessary, but this requirement depends on the demands of the sport. Generally, it is important to ensure high pre-competition glycogen stores and to maintain fluid balance. There is limited evidence to support the use of dietary supplements, but some, including perhaps creatine and caffeine, may be beneficial.     

Case study: nutrition challenges of a marathon runner with a gastric bypass

A new type of athlete is appearing in the offices of sports dietitians: formerly obese people who have undergone gastric bypass surgery and now aspire to be marathoners, triathletes, and other types of endurance athletes. The standard nutrition advice offered to bypass patients is contrary to the standard sports advice given to athletes. Bypass athletes need to limit carbohydrates, fluids, and energy intake and consume a protein-based diet. This case study describes the sport nutrition concerns of a woman who, after having gastric bypass surgery, trained to run a marathon (42 km). Because of her limited ability to consume food and fluids, she experienced difficulty preventing fatigue and dehydration during her long training runs and the marathon itself. She learned through trial and error how to survive the nutritional challenges and complete the marathon. Health professionals need to be aware of the potential medical risks associated with endurance exercise in gastric bypass patients. Research is needed to determine the best sports nutrition practices for bypass patients. Only then can sport dietitians better educate this small but growing contingent of endurance athletes so the athletes can meet their training and performance goals and reduce their risk of experiencing serious health consequences.     

The role of vitamin C in athletic performance.

There is widespread belief among athletes that special nutritional practices–in particular high-protein diets–will enhance their achievements in competition. Supplementation with vitamins, especially vitamin C, is equally popular. But because genetic predisposition, hard physical training and psychological factors play a most important role in determining performance, and because any potential difference in achievement will be small, it is almost impossible to obtain scientific evidence of a beneficial effect of a particular nutrient. There have been many investigations during the past four decades of the potential effect of high-dose vitamin C supplementation on physical performance. The variables used have included maximum oxygen uptake, blood lactic acid levels, and heart rate after exercise, and in some cases performance was assessed in competitive events. The results have been equivocal: Most studies could not demonstrate an effect. On the other hand, a suboptimal vitamin C status results in an impaired working capacity which can be normalized by restoring vitamin C body pools. Athletes, who follow irrational, unhealthy eating patterns often not including vitamin-C-containing fruit and vegetables, are in need of nutrition education.     

The role of vitamin C in athletic performance

There is widespread belief among athletes that special nutritional practices--in particular high-protein diets--will enhance their achievements in competition. Supplementation with vitamins, especially vitamin C, is equally popular. But because genetic predisposition, hard physical training and psychological factors play a most important role in determining performance, and because any potential difference in achievement will be small, it is almost impossible to obtain scientific evidence of a beneficial effect of a particular nutrient. There have been many investigations during the past four decades of the potential effect of high-dose vitamin C supplementation on physical performance. The variables used have included maximum oxygen uptake, blood lactic acid levels, and heart rate after exercise, and in some cases performance was assessed in competitive events. The results have been equivocal: Most studies could not demonstrate an effect. On the other hand, a suboptimal vitamin C status results in an impaired working capacity which can be normalized by restoring vitamin C body pools. Athletes, who follow irrational, unhealthy eating patterns often not including vitamin-C-containing fruit and vegetables, are in need of nutrition education.     

Position of the American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and athletic performance

It is the position of the American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine that physical activity, athletic performance, and recovery from exercise are enhanced by optimal nutrition. These organizations recommend appropriate selection of food and fluids, timing of intake, and supplement choices for optimal health and exercise performance. This position paper reviews the current scientific data related to the energy needs of athletes, assessment of body composition, strategies for weight change, the nutrient and fluid needs of athletes, special nutrient needs during training, the use of supplements and nutritional ergogenic aids, and the nutrition recommendations for vegetarian athletes. During times of high physical activity, energy and macronutrient needs—especially carbohydrate and protein intake—must be met in order to maintain body weight, replenish glycogen stores, and provide adequate protein for building and repair of tissue. Fat intake should be adequate to provide the essential fatty acids and fat-soluble vitamins, as well as to help provide adequate energy for weight maintenance. Overall, diets should provide moderate amounts of energy from fat (20% to 25% of energy); however, there appears to be no health or performance benefit to consuming a diet containing less than 15% of energy from fat. Body weight and composition can affect exercise performance, but should not be used as the sole criterion for sports performance; daily weigh-ins are discouraged. Consuming adequate food and fluid before, during, and after exercise can help maintain blood glucose during exercise, maximize exercise performance, and improve recovery time. Athletes should be well-hydrated before beginning to exercise; athletes should also drink enough fluid during and after exercise to balance fluid losses. Consumption of sport drinks containing carbohydrates and electrolytes during exercise will provide fuel for the muscles, help maintain blood glucose and the thirst mechanism, and decrease the risk of dehydration or hyponatremia. Athletes will not need vitamin and mineral supplements if adequate energy to maintain body weight is consumed from a variety of foods. However, supplements may be required by athletes who restrict energy intake, use severe weight-loss practices, eliminate one or more food groups from their diet, or consume high-carbohydrate diets with low micronutrient density. Nutritional ergogenic aids should be used with caution, and only after careful evaluation of the product for safety, efficacy, potency, and whether or not it is a banned or illegal substance. Nutrition advice, by a qualified nutrition expert, should only be provided after carefully reviewing the athlete's health, diet, supplement and drug use, and energy requirements. J Am Diet Assoc. 2000;100:1543-1556.     

The prevalence of hypertension,obesity and dyslipidemia in individuals of over 30 years of age belonging to minorities from the pasture area of Xinjiang

Background

Childhood obesity and its related metabolic and psychological abnormalities are becoming serious health problems in China. Effective, feasible and practical interventions should be developed in order to prevent the childhood obesity and its related early onset of clinical cardiovascular diseases. The objective of this paper is to describe the design of a multi-centred random controlled school-based clinical intervention for childhood obesity in China. The secondary objective is to compare the cost-effectiveness of the comprehensive intervention strategy with two other interventions, one only focuses on nutrition education, the other only focuses on physical activity.

Methods/Design

The study is designed as a multi-centred randomised controlled trial, which included 6 centres located in Beijing, Shanghai, Chongqing, Shandong province, Heilongjiang province and Guangdong province. Both nutrition education (special developed carton style nutrition education handbook) and physical activity intervention (Happy 10 program) will be applied in all intervention schools of 5 cities except Beijing. In Beijing, nutrition education intervention will be applied in 3 schools and physical activity intervention among another 3 schools. A total of 9750 primary students (grade 1 to grade 5, aged 7-13 years) will participate in baseline and intervention measurements, including weight, height, waist circumference, body composition (bioelectrical impendence device), physical fitness, 3 days dietary record, physical activity questionnaire, blood pressure, plasma glucose and plasma lipid profiles. Data concerning investments will be collected in our study, including costs in staff training, intervention materials, teachers and school input and supervising related expenditure.

Discussion

Present study is the first and biggest multi-center comprehensive childhood obesity intervention study in China. Should the study produce comprehensive results, the intervention strategies would justify a national school-based program to prevent childhood obesity in China.

Trial Registration

Chinese clinical trial registry (Primary registry in the WHO registry network) Identifier: ChiCTR-TRC-00000402     

Nutritional concerns for the child and adolescent competitor

With exercise for sports competition in children and adolescents, acute nutrient needs will change. Fluid intake to ensure the replacement of water and minerals (electrolytes) lost in sweat is important. Energy needs also increase because of the elevated energy expenditure with physical activity. Arguably carbohydrate is the recommended source of training needs, although research has yet to be done to show performance benefits in young athletes on a high-carbohydrate diet. In the majority of sports, an increased intake of food naturally occurs to accommodate the day-to-day nutrient needs of young athletes, and unlike non-athlete, young competitors typically come closer to meeting their requirements for micronutrients. Nonetheless, certain athletic groups may be at risk for shortfalls in their diet. Compared to athletes in team sports, participants in weight-control sports may be at greater risk of failing to meet requirements for energy, protein, and some micronutrients. Endurance athletes, particularly female distance runners, may have intake deficits for the minerals iron and calcium. Acute issues such as heat illness and chronic concerns that include impaired growth and development, and the risk of injuries that include stress fractures may be an outcome of inadequate nutrition during physical training.     

Sports and health, view-point of a sociologist]

The expression "health" covers a wide physical, psychic and social range. The phenomenon "sport", in its cultural form, has evolved historically and is constantly changing. In the today's sport movement, we can see differences in age, sex, and social status related to the type of sport practised, the frequency and the motivation as well as its form of organization. The main inducement for practising sport is by friends. At the end of the article, the author points out that it is problematic to misuse sport for pedagogic aims or aims of preventive medicine, because in such cases, sport runs the risk to lose its initial objective which, originally, had no definite goal other than the experience itself. Moreover, it is irrational to believe that sport alone can cure civilization diseases both in the physical as well as in the psychic and social range.     

Morphological and functional characteristics of the left ventricle in athletes of various ages, and performing at various levels

One of the most important effects of regular physical training is the adaptation of the cardiovascular system. The basic importance of an "athlete's heart" is manifested in two fields, one is public health, the other competitive sport. AIM: 1. Can the higher E/A quotient of physically active persons be explained by the training bradycardia, or can it be supposed as an independent effect of regular physical exercise? 2. Which training-induced heart characteristics seem to be different in players of various ball-games? 3. How are cardiac data related to the relative aerobic power as most indicative index of endurance performance? METHODS: Two-dimensionally guided M-mode and Doppler echocardiographic data of different athletic and non-athletic subjects were compared with each other, differences between data of different athletic groups were also analysed. RESULTS: 1. E/A quotient characterises left ventricular (LV) diastolic function, but it highly depends on the heart rate. The higher E/A found in young athletes does not seem to be an independent effect of the regular physical training. 2. Investigating the data of different ball-game-players, characteristic differences were seen. In the myocardial hypertrophy and in the resting heart rate water polo players were the best, volleyball players the worst, but the values of the latter were also better than those of non-athletes. 3. In the pooled group of non-athletes and of competitors of several kinds of sports (endurance athletes, ball-game-players, power-and-sprint-events athletes) all measured parameters correlated significantly with the relative maximal oxygen consumption. CONCLUSIONS: 1. The higher E/A in elderly subjects suggests that regular physical training can diminish the age-associated impairment of diastolic function. 2. For the high intensity training and for the long competition period a special endurance training program would be useful for volleyball players. 3. The higher was the proportion of endurance activity in the training and competitive program, the stronger were the correlations with the relative aerobic capacity.     

Position of the American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance

It is the position of the American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine that physical activity, athletic performance, and recovery from exercise are enhanced by optimal nutrition. These organizations recommend appropriate selection of foods and fluids, timing of intake, and supplement choices for optimal health and exercise performance. This updated position paper couples a rigorous, systematic, evidence-based analysis of nutrition and performance-specific literature with current scientific data related to energy needs, assessment of body composition, strategies for weight change, nutrient and fluid needs, special nutrient needs during training and competition, the use of supplements and ergogenic aids, nutrition recommendations for vegetarian athletes, and the roles and responsibilities of sports dietitians. Energy and macronutrient needs, especially carbohydrate and protein, must be met during times of high physical activity to maintain body weight, replenish glycogen stores, and provide adequate protein to build and repair tissue. Fat intake should be sufficient to provide the essential fatty acids and fat-soluble vitamins, as well as contribute energy for weight maintenance. Although exercise performance can be affected by body weight and composition, these physical measures should not be a criterion for sports performance and daily weigh-ins are discouraged. Adequate food and fluid should be consumed before, during, and after exercise to help maintain blood glucose concentration during exercise, maximize exercise performance, and improve recovery time. Athletes should be well hydrated before exercise and drink enough fluid during and after exercise to balance fluid losses. Sports beverages containing carbohydrates and electrolytes may be consumed before, during, and after exercise to help maintain blood glucose concentration, provide fuel for muscles, and decrease risk of dehydration and hyponatremia. Vitamin and mineral supplements are not needed if adequate energy to maintain body weight is consumed from a variety of foods. However, athletes who restrict energy intake, use severe weight-loss practices, eliminate one or more food groups from their diet, or consume unbalanced diets with low micronutrient density, may require supplements. Because regulations specific to nutritional ergogenic aids are poorly enforced, they should be used with caution, and only after careful product evaluation for safety, efficacy, potency, and legality. A qualified sports dietitian and in particular in the United States, a Board Certified Specialist in Sports Dietetics, should provide individualized nutrition direction and advice subsequent to a comprehensive nutrition assessment.     

Comparison of dietary intake and eating behavior of professional road cyclists during training and competition

The dietary intake and eating behavior of a group of professional elite road cyclists during high intensity training and competition was compared. Their eating pattern consisted of several snacks throughout the race or training, a meal eaten no later than 1 hr postexercise, supper, and breakfast. Protein intake showed a significant difference between evaluation times expressed in three ways: per total amount intake, by kg body weight, and percentage of energy supplied. Due to the high energy intake of these cyclists during training and competition (22.9 +/- 1.5, 22.4 +/- 1.7 MJ, respectively) they presented a high consumption of each macronutrient both in competition and in training. The eating behavior of these athletes was similar during breakfast (possibility to choose from among approximately 25 foods) and supper (set menu), with variation in the energy intake and a similar relative contribution of the different macronutrients. In general, it is possible to consider the professional road cyclists as a homogeneous group with a similar nutrition intake, eating habits, and nutritional needs throughout the more demanding periods of the season. Furthermore, differences found in protein intake between periods could not be explained by differences in the food available in competition and training periods.     

Sun exposure and sun protection behaviours among young adult sport competitors

OBJECTIVES: To explore the relationship between sun protection and physical activity in young adults (18-30 years) involved in four organised sports. METHODS: Participants (n=237) in field hockey, soccer, tennis and surf sports completed a self-administered survey on demographic and sun-protective behaviours while playing sport. Differences in sun-protective behaviour were explored by sport and by gender. RESULTS: Sunburn during the previous sporting season was high (69%). There were differences between sports for sunburn, sunscreen use and reapplication of sunscreen. Lifesaving had the highest rates compared with the other three sports. Hats and sunglasses worn by participants varied significantly by sports. A greater proportion of soccer and hockey players indicated they were not allowed to wear a hat or sunglasses during competition. For all sports, competition was played mainly in the open with no shade provision for competitors while they were playing. There were some gender differences within each of the sports. Female soccer and tennis players were more likely to wear sunscreen compared with males. Female hockey players were more likely to wear a hat compared with males. CONCLUSIONS: Our findings highlight that there is still room for improvement in sun-protective behaviours among young adult sport competitors. There is a need for a systematic approach to sun protection in the sporting environments of young adults. IMPLICATIONS: Health promotion efforts to increase physical activity need to be paired with sun protection messages.     

Diet of an Olympian: Food with a purpose

Olympic medals are often decided by a fraction of a per cent. Over the last 20 years, elite athletes have taken a systematic approach to improving their performance. Performance nutrition is the systematic use of nutrition science to improve sporting performance and is increasingly being used by elite athletes. There are three areas of sporting performance where performance nutrition may be applied, namely the prevention of illness and injury, facilitation of adaptation from training and improvement of competition performance. Performance nutrition can help prevent illness by providing the correct amount of energy and macronutrients to match the energy needs of training and to prevent fatigue. Post‐exercise carbohydrate and protein intake supports recovery from exercise and enables athletes to be in a position to train again. Nutrients such as calcium can promote bone health and prevent injury. Nutrient intake around training facilitates the adaptation to exercise. Protein intake post resistance exercise enhances the hypertrophy adaptation to exercise and manipulation of carbohydrate intake facilitates the adaptive response to endurance exercise. Use of both macronutrients and ergogenic aids (such as beetroot juice) around competition can enhance the sporting performance.     

Caffeinated Drinks and Physical Performance in Sport: A Systematic Review

Caffeine (1,3,7-trimethylxanthine) is one of the most common substances used by athletes to enhance their performance during competition. Evidence suggests that the performance-enhancing properties of caffeine can be obtained by employing several forms of administration, namely, capsules/tablets, caffeinated drinks (energy drinks and sports drinks), beverages (coffee), and chewing gum. However, caffeinated drinks have become the main form of caffeine administration in sport due to the wide presence of these products in the market. The objective of this systematic review is to evaluate the different effects of caffeinated drinks on physical performance in various sports categories such as endurance, power-based sports, team sports, and skill-based sports. A systematic review of published studies was performed on scientific databases for studies published from 2000 to 2020. All studies included had blinded and cross-over experimental designs, in which the ingestion of a caffeinated drink was compared to a placebo/control trial. The total number of studies included in this review was 37. The analysis of the included studies revealed that both sports drinks with caffeine and energy drinks were effective in increasing several aspects of sports performance when the amount of drink provides at least 3 mg of caffeine per kg of body mass. Due to their composition, caffeinated sports drinks seem to be more beneficial to consume during long-duration exercise, when the drinks are used for both rehydration and caffeine supplementation. Energy drinks may be more appropriate for providing caffeine before exercise. Lastly, the magnitude of the ergogenic benefits obtained with caffeinated drinks seems similar in women and men athletes. Overall, the current systematic review provides evidence of the efficacy of caffeinated drinks as a valid form for caffeine supplementation in sport.     

Nutrition assessment of athletes: a model for integrating nutrition and physical performance indicators.

Athletes, like all people, have special nutritional needs based on their age, lifestyle, health status, level of physical activity, physical conditioning, and type of sport. The diets of many athletes are inadequate due to overly restrictive eating habits, nutrition misinformation, dietary fads, and/or obsession with weight and food. There is a growing need for sports nutrition counseling and education to help athletes improve their eating habits. However, before attempting to develop intervention strategies, sports nutritionists should assess the metabolic changes that take place during exercise and how these changes affect nutrition status. In addition, it is important to consider how psychosocial factors may influence an athlete's eating habits and his/her ability to make positive changes. A two-pronged model is introduced that can be used as a guide for the practitioner in interpreting relevant data and integrating physiological and psychological considerations for the design of individualized nutrition care plans for athletes.     

Clinical nutrition and foodservice personnel in teaching hospitals have different perceptions of total quality management performance

OBJECTIVE: To investigate the perceived total quality management (TQM) performance of their department by clinical nutrition managers and dietitians, and foodservice managers and supervisors, in hospital food and nutrition service departments. DESIGN: Using a 2-part questionnaire containing items about 3 constructs of TQM performance and demographic characteristics, participants rated their perceptions of TQM performance. SUBJECTS: Employees in 7 Council of Teaching Hospitals. Of the 128 possible respondents, 73 (57%) completed the study. STATISTICAL ANALYSES PERFORMED: Correlation analysis to identify relationships between demographic characteristics and TQM performance. Analysis of variance to investigate statistical differences among hospitals and between subject groups and types of employment positions. RESULTS: Three TQM constructs--organization, information, and quality management--were evaluated. The clinical nutrition manager and dietitian group had mean ratings between 3.1 and 4.7 (5-point Likert scale); the foodservice manager and supervisor group had mean ratings from 2.7 to 4.0. Education level was significantly correlated (r = 0.44) to performance of employee training in the clinical nutrition group. The number of employees directly supervised was negatively correlated (r = -0.21) to the performance of employee training in the foodservice group. APPLICATIONS: As the dynamic roles of dietitians change, many dietitians will occupy management positions in organizations such as restaurants, health food stores, food processing/distribution companies, and schools. This study demonstrates how a TQM survey instrument could be applied to clinical nutrition and foodservice settings. Dietitians will need to assess TQM in their workplace facilities, especially because of the direct links of TQM to productivity and client satisfaction.     

Fluids and hydration in prolonged endurance performance

Numerous studies have confirmed that performance can be impaired when athletes are dehydrated. Endurance athletes should drink beverages containing carbohydrate and electrolyte during and after training or competition. Carbohydrates (sugars) favor consumption and Na(+) favors retention of water. Drinking during competition is desirable compared with fluid ingestion after or before training or competition only. Athletes seldom replace fluids fully due to sweat loss. Proper hydration during training or competition will enhance performance, avoid ensuing thermal stress, maintain plasma volume, delay fatigue, and prevent injuries associated with dehydration and sweat loss. In contrast, hyperhydration or overdrinking before, during, and after endurance events may cause Na(+) depletion and may lead to hyponatremia. It is imperative that endurance athletes replace sweat loss via fluid intake containing about 4% to 8% of carbohydrate solution and electrolytes during training or competition. It is recommended that athletes drink about 500 mL of fluid solution 1 to 2 h before an event and continue to consume cool or cold drinks in regular intervals to replace fluid loss due to sweat. For intense prolonged exercise lasting longer than 1 h, athletes should consume between 30 and 60 g/h and drink between 600 and 1200 mL/h of a solution containing carbohydrate and Na(+) (0.5 to 0.7 g/L of fluid). Maintaining proper hydration before, during, and after training and competition will help reduce fluid loss, maintain performance, lower submaximal exercise heart rate, maintain plasma volume, and reduce heat stress, heat exhaustion, and possibly heat stroke.