Current issues in sports nutrition in athletes.
Annotation 1. (programming, compiler) annotation - Extra information associated with a particular point in a document or program. Annotations may be added either by a compiler or by the programmer. : The benefits of sports nutrition Sports nutrition is applied in most sports training, however it is most dominant in strength sports (for example weight lifting and bodybuilding) and endurance sports (for example cycling, running, triathlon). evaluation and counseling are important to both elite athletes and active men and women of all ages who want to optimize health and performance. Proper nutrition proper nutrition,
n in Tibetan medicine, a therapeutic concept that begins with a digestive formulation because it is believed that a medical condition is primarily the result of a nutritional dysfunction or disturbance in the process of delivering nutrients. is essential to staying metabolically healthy during a run, a draining practice, or as a year-round philosophy to perform maximally and to avoid or recover from injury. Major issues related to nutrition in sports include weight control, body composition, carbohydrate loading carbohydrate loading
A dietary practice that increases carbohydrate reserves in muscle tissue through the consumption of extra quantities of high-starch foods and is often followed by some endurance athletes prior to competition. , hydration hydration /hy·dra·tion/ (hi-dra´shun) the absorption of or combination with water.
1. The addition of water to a chemical molecule without hydrolysis.
2. , eating disorders eating disorders, in psychology, disorders in eating patterns that comprise four categories: anorexia nervosa, bulimia, rumination disorder, and pica. Anorexia nervosa is characterized by self-starvation to avoid obesity. , and supplementation, to name a few. General sports nutrition guidelines and sports-specific concerns are reviewed.
Sports nutrition encompasses several subjects including the energy, nutrient and fluid needs of athletes, assessment of body composition, strategies for weight change, special nutrient needs during training, competition, and recovery, and the use of supplements and nutritional ergogenic aids.
Active people require more energy to maintain lean tissue lean tissue
muscle tissue without fat. mass, for immune and reproductive function, and optimum athletic performance. Meeting calorie needs can be difficult for some athletes, especially in those sports where severe weight-loss practice and restricted intakes are common. When energy intake is limited, the body uses fat and lean tissues for energy, thus resulting in loss of strength and performance. Chronic undernutrition Undernutrition
A type of malnutrition caused by inadequate food intake or the body's inability to make use of needed nutrients.
Mentioned in: Appetite-Enhancing Drugs
see malnutrition, starvation. also places the athlete at risk for micronutrient mi·cro·nu·tri·ent
A substance, such as a vitamin or mineral, that is essential in minute amounts for the proper growth and metabolism of a living organism. deficiency. While there are recommended dietary allowances Recommended Dietary Allowance (RDA)
The Recommended Dietary Allowances (RDAs) are quantities of nutrients in the diet that are required to maintain good health in people. and activity factors for calculating calorie needs, the best indication that energy needs are being met is the athlete demonstrating maintenance of weight and body composition while training for a sport.
Protein, Carbohydrate, and Fat Needs in Athletes
Protein requirements are increased in athletes. Endurance athletes need 1.2 to 1.4 g/kg body mass per day. Resistance and strength-trained athletes need 1.6 to 1.7 g/kg body mass per day. This is compared with 0.8 to 1.0 g/kg body mass for nonathletes. For example, a 200-pound long distance runner distance runner
A runner who competes in distance races. would require approximately 118 g protein, while a 200-pound football player would need roughly 150 g. The nonathlete would only require about 75 g protein per day. (See Table for amount in protein found in food.)
Carbohydrate needs vary in athletes depending on overall energy needs, type of sport, and the sex of the athlete. Recommendations range from 6 to 10 g/kg body mass per day with the goals being maintenance of blood-glucose levels during exercise, and to replace muscle glycogen glycogen (glī`kəjən), starchlike polysaccharide (see carbohydrate) that is found in the liver and muscles of humans and the higher animals and in the cells of the lower animals. . In fact, replacing muscle glycogen is crucial for recovery from one training session to the next to maximize training gains. It is important to have nutritious carbohydrate snacks on hand immediately after training to initiate the re-fueling process. The following snacks are examples that provide sufficient carbohydrate to optimize recovery:
Male athlete (target 60-80 g carbohydrate).
* One 8-oz carton fruit yogurt + cereal bar + 8 oz of fruit juice
* 8 oz milk + cereal bar + 1 banana
* 32 oz sports drink sports drink Performance drink Sports medicine A thirst-quenching beverage used in sports-related activities, which may boost energy and/or help build muscle mass; water, sugar, salt, potassium are common to all SDs. See Hydrotherapy, Water.
Female athlete (target 40-50 g carbohydrate).
* One 8 oz carton fruit yogurt + cereal bar or 1 banana
* 8oz milk + cereal bar
* 24 oz sports drink
Fat intake should also correspond with overall energy needs, with fat making up 20 to 25% of total energy consumed to provide essential fatty acids Essential fatty acids
Sources of fat in the diet, including omega-3 and omega-6 fatty acids.
Mentioned in: Nutritional Supplements and fat-soluble vitamins Fat-soluble vitamins
Fat-soluble vitamins can be dissolved in oil or in melted fat.
Mentioned in: sub> Deficiency (A, D, E, and K). There is no research to support recommending very-low-fat (<15%) or high-fat diets to athletes. An athlete requiring 3,000 calories daily should, therefore, consume at least 50 g fat (15% calories from fat). (See Table for fat content in foods.)
Research has clearly documented the beneficial effects of nutrition on physical performance. It is the position of both the American College of Sports Medicine '''Founded in 1954, the AMERICAN COLLEGE OF SPORTS MEDICINE is the largest sports medicine and exercise science organization in the world. More than 20,000 international, national and regional members are dedicated to advancing and integrating scientific research to provide educational (ACSM ACSM American College of Sports Medicine. ) and the American Dietetic Association The American Dietetic Association (ADA) is the United States' largest organization of food and nutrition professionals, with nearly 65,000 members. Approximately 75 % of ADA's members are registered dietitians and about 4 % are dietetic technicians, registered. (ADA Ada, city, United States
Ada (ā`ə), city (1990 pop. 15,820), seat of Pontotoc co., S central Okla.; inc. 1904. It is a large cattle market and the center of a rich oil and ranch area. ) in particular, that physical activity, athletic performance and recovery from exercise are enhanced by optimal nutrition. During times of intense physical activity, energy and macronutrient macronutrient /mac·ro·nu·tri·ent/ (-noo´tre-ent) an essential nutrient required in relatively large amounts, such as carbohydrates, fats, proteins, or water; sometimes certain minerals are included, such as calcium, chloride, or sodium. needs must be met to maintain body weight, replenish glycogen stores, and provide adequate protein for building and repairing tissue. Carbohydrate, protein, and fat intake are all crucial to optimal performance. Athletes must be well-hydrated before exercise, and consume adequate liquid during and after performance to balance fluid loss. Appropriate selection of foods and fluids, the timing of intake, and supplement choices are important for optimal health and exercise performance.
Many athletes today rely on sports nutritionists to assist them in designing meal plans and eating strategies to give them a competitive edge. While each sport entails different training regimens and performance goals, it is clear that a proper diet can help any athlete reach their potential. Likewise, persistent fatigue, poor recovery, illness and unwanted weight loss are the most common result of undernutrition or suboptimal Suboptimal
A solution is called suboptimal if a part of the solution has been optimized without regards to the overall objective. eating habits. The following is a small subset (not intended to be a representative or exhaustive list) of specific sports and common nutrition issues for each. It is the authors' goal to address as many specific issues as possible using a variety of sports played by both sexes.
Football is a game of speed, skill, and strength, all of which may be affected by the athlete's nutrition. Carbohydrate is needed to fuel hard working muscles; with 60 to 70% of calories coming from bread, cereal, rice, pasta, fruit, vegetables, and low-fat dairy products dairy products dairy npl → produits laitier
dairy products dairy npl → Milchprodukte pl, Molkereiprodukte pl (about 2/3 of the plate at each meal).
Muscle bulk and strength. A high-energy (calorie) diet is the key to bulking up. Although protein is important, and football players need more than nonathletes, carbohydrate should be the primary energy source. Coaches and parents should encourage players to avoid skipping meals. Snack before practice and bring a post-training snack to eat in the locker room. Good choices are high carbohydrate foods such as crackers, fruit, or a bagel with a sports drink.
Recovery eating recommendations. The goal for recovery eating is to facilitate rapid recovery of muscle glycogen levels. Restoring these levels assures the athletes' energy fuel needs for the day are met. This strategy helps fight fatigue and build muscle mass in the gym. Players who fail to plan for long training sessions or road-trips often fail to replenish muscle glycogen stores. Under-nutrition can result in fatigue, especially late in the season, and struggles in the gym when attempting to increase muscle mass despite working hard.
Fluid needs. Players must be hydrated hy·drat·ed
Chemically combined with water, especially existing in the form of a hydrate.
Adj. 1. hydrated - containing combined water (especially water of crystallization as in a hydrate)
hydrous properly to avoid fatigue both on game day and during practice sessions. Sports drinks are recommended over water because they taste good, contain electrolytes, and may help prevent cramping cramping
see cramp. . Players should be weighed before and after practice to be sure fluid losses are replaced. One pound should be replaced with at least 20 ounces of fluid. Players should be educated regarding spitting (drinks must be swallowed to hydrate hydrate (hī`drāt), chemical compound that contains water. A common hydrate is the familiar blue vitriol, a crystalline form of cupric sulfate. Chemically, it is cupric sulfate pentahydrate, CuSO4·5H2O. the body) and urinating (the goal is relatively frequent, light-colored urine).
Professional golfers can spend up to eight hours a day on the golf course. Most modern players also include strength training, aerobic conditioning Aerobic conditioning is a process whereby one trains the heart to pump blood more efficiently, allowing more oxygen to get to muscles and organs.
Aerobic conditioning is used to train people to perform better while doing something for a long period of time, running a mile , and flexibility in their training schedule to strengthen the muscles involved in golf, improve endurance, and minimize the risk of injury. Golf is primarily a game of skill. Therefore, top golfers come in many shapes and sizes. In recent times, there is a tendency for top golfers to be fitter and leaner than ever before. Overweight golfers suffer greater heat intolerance heat intolerance Sports medicine A condition caused by the thermal challenges of exercise, resulting in various responses from cramps and exhaustion to heat syncope, stroke, death. See Heat-related death, Heat wave. in hot conditions. Carrying excess body fat may also make a golfer more susceptible to injury. Common nutrition issues include:
Training nutrition. Intake should include primarily carbohydrates with moderate amounts of protein and less fat. A variety of foods from each food group is recommended.
Tournaments. Players will usually miss a meal while playing a round. They may be faced with no carbohydrate intake for five or six hours. Players should carry fruit or cereal bars to maintain their energy levels during tournament play.
Sweat losses. Sweat loss is high when tournaments are played in hot and windy environments. It is important for players to carry water with them. Although many golf courses provide drink stations, they may be at infrequent intervals, and not allow sufficient opportunity for fluid replacement during a game.
Alcohol intake. If alcohol is used, players should consume a few nonalcohol drinks first and alternate these with one or two alcoholic drinks thereafter. Both dehydration and low blood-sugar levels are possible during competition, and may impair golfing performance.
Elite gymnasts train in excess of 20 to 30 hours per week. Typically, daily training sessions are scheduled morning and afternoon lasting for 2 to 3 hours each. An exercise can last for as little as a few seconds (vault) to over one minute (floor exercise). Technical skill perfection, muscular strength, explosive power relative to body weight, flexibility, and artistic impression are all essential characteristics required for world-class performance. Female gymnasts are small, lean (low percent body fat), and well-muscled, which results in a high power-to-weight ratio Power-to-weight ratio (specific power) is a calculation commonly applied to engines and other mobile power plants to enable the comparison of one unit (design) to another. Power-to-weight ratio is a measurement of actual performance of any engine (power plant). . Generally, female gymnasts reach their peak power-to-weight ratio before puberty, and are ready for elite international competition at the minimum age requirement. Male gymnasts are lean and heavily muscled, yet possess adequate flexibility and agility to perform the required skills at elite international competition. Successful male gymnasts have a high power-to-weight ratio, which is normally reached during their twenties, making them somewhat older than elite female gymnasts. Common nutrition issues include:
Calcium deficiency calcium deficiency
Inadequate supply or metabolism of calcium, the main structural element of bones and teeth. Its metabolism is regulated by vitamin D, phosphorus, and hormones (see parathyroid gland). . Female gymnasts should consume calcium-rich foods at meals and snacks to meet their daily calcium needs for bone mineral development. These foods include low-fat or fat-free dairy products, leafy green vegetables, corn tortillas, and canned salmon.
Eating disorders. Female gymnastics is a sport where athletes are required to maintain a low weight-to-height ratio if they wish to perform at a high level. This fact places these athletes at greater risk of developing an eating disorder eat·ing disorder
Any of several patterns of severely disturbed eating behavior, especially anorexia nervosa and bulimia, seen mainly in female teenagers and young women. than athletes involved in other sports. It is important to have a weight management plan involving the doctor, the sports dietitian dietitian /di·e·ti·tian/ (di?e-tish´in) one skilled in the use of diet in health and disease.
di·e·ti·tian or di·e·ti·cian
A person specializing in dietetics. , the coach and the gymnast to ensure that athletes develop normally during their adolescent years.
Fluid intake. Sweat losses tend to be small compared with those of other athletes. However, it is still important for gymnasts to stop regularly during their long training sessions to replace lost fluid. Some gymnasts concerned with their weight reduce their fluid intake to reduce body weight. For these athletes, it is crucial to point out that a decrease in weight as a result of sweating is purely a reflection of lost fluid, not a decrease in body fat stores.
Energy needs. Female gymnasts often consume low calorie diets low calorie diet
A diet of 1,200 calories or less per day. , placing them at risk for calcium and iron deficiency iron deficiency A relative or absolute deficiency of iron which may be due to chelation in the GI tract, loss due to acute or chronic hemorrhage or dietary insufficiency Sources Meat, poultry, eggs, vegetables, cereals, especially if fortified with iron; per the . Adolescent male gymnasts may have difficulty consuming enough food to keep pace with the demands of growth, training, and maintenance of muscle mass.
Serious commitment to training is needed, with 6 to 12 sessions per week and as many as 6 hours daily. Swimmers may also perform land-based aerobic training as well as weight training sessions. Pronounced upper body muscle development and low body fat is the norm, although some fat in the right distribution may enhance floatation. Many top swimmers are teenagers. Males are typically in a period of heavy growth and muscular development Muscular Development is an American fitness and bodybuilding magazine first published in 1964. It was founded by Bob Hoffman, the owner and founder of the York Barbell Company. Its editor from 1964 to its sale in 1986 was John Grimek. , requiring high energy support. Females undergoing hormonal changes which promote increased body fat may struggle to maintain low body fat levels. Common nutrition issues include:
Daily recovery. A high-energy, high-carbohydrate diet is recommended. Swimmers who travel long distances to train may need to pack nutritional snacks to begin the refueling process rather than waiting until they get home. Fatigue, loss of body weight and poor performance can result without a good plan that includes several snacks during the day which make good use of high energy foods.
Iron status. Female swimmers are especially at risk, so iron levels should be checked regularly when in heavy training. Iron-rich foods should be consumed daily.
Unwanted fat gain. Fat gain can be avoided during the off-season by decreasing total energy intake.
Fluid needs in training. Sweat losses are not always obvious because the athlete is wet. Swimmers should keep drinks on the pool deck and drink during rest periods or between sets.
Triathlon triathlon, athletic event made up of three contests. Since the 1970s the term has come to mean especially a race combining swimming, bicycling, and running. A notable example is Hawaii's Ironman Triathlon, held since 1978, which features a 2.
A combination of three exercises, triathalon includes swimming, cycling, and running. These events are completed over various distances ranging from one hour events to all-day races. Most triathletes train twice daily and routinely combine disciplines into one session to adapt their bodies to the stresses of competition. Professionals may train three times daily. Triathletes commonly strive to achieve a low body-fat level, and this fascination with weight loss leads some to try fad diets. Common nutrition issues include:
Daily recovery. High daily energy, carbohydrate and protein requirements exist.
Timing of meals around training sessions. Planning is crucial.
Carbohydrate loading. This practice is popular before competition and can positively affect performance.
Prerace eating. Early start times make skipping breakfast tempting for some.
Eating during training and competition. Planning nutritious snacks is essential to provide carbohydrate to working muscles and to meet daily energy needs and nutrition requirements. Athletes are encouraged to use the cycling portion to consume much-needed fluids and fuel.
Meeting fluid needs. With high sweat losses, a conscious effort is needed to prevent dehydration (the most common cause of medical treatment following triathalons).
Weight management. High-protein, low-carbohydrate diets used for weight loss are not recommended because they are low in calories. Risks include failure to recover from training, and compromising immune system immune system
Cells, cell products, organs, and structures of the body involved in the detection and destruction of foreign invaders, such as bacteria, viruses, and cancer cells. Immunity is based on the system's ability to launch a defense against such invaders. function.
Iron. Damage to red blood cells Red blood cells
Cells that carry hemoglobin (the molecule that transports oxygen) and help remove wastes from tissues throughout the body.
Mentioned in: Bone Marrow Transplantation
red blood cells from the pounding of feet on the track, iron losses in sweat, gastrointestinal bleeding gastrointestinal bleeding Any hemorrhage into the GI tract lumen, from esophagus–eg, from ruptured esophageal varices, to anus–eg from hemorrhoids which may occur through heavy training or anti-inflammatory use, low dietary intake of well-absorbed iron, and menstrual losses in females can lead to iron deficiency.
Regardless of the specific sport, medical nutrition therapy or nutrition counseling can be described as the "care" of staying metabolically healthy during a run, during seasonal practice and competition, or as a year-round philosophy to perform maximally and to avoid or recover from injury. Supplementation and additives are ancillary subjects and can be positive or negative for the user. We have described several issues commonly encountered by physicians and dietitians to illustrate the varied and dynamic nature of sports nutrition.
Table. Foods, nutrients, and body function Average number of grams per serving (a) Bread, cereal, Meat, Fish, Calories rice, pasta, Poultry, per starchy Eggs, gram vegetable Fruit Vegetable Cheese Carbohydrate 4 15g 15g 5g 0g Protein 4 2g 0g 3g 21g Fat 9 1g 0g 0g 15g Alcohol 7 Water (b) 0 Average number of grams per serving (a) Added fats (butter, oils, mayonnaise) Role in body function Carbohydrate 0g The major source of fuel, essential for brain function. The body will convert fat and/or protein to glucose in the absence of carbohydrate intake (gluconeogenesis). Carbohydrate is stored in the skeletal muscle and liver in the form of glycogen. Protein 0g Source of essential amino acids necessary for the body to synthesize its own proteins and nitrogen-containing molecules. Proteins also provide life-sustaining enzymes, immunoproteins, or antibodies and peptide hormones that control many body functions. Their structural role includes both the contractile proteins of the muscles and the fibrous proteins in connective tissue, skin, nails, and hair. Fat 5g Source of essential fat-soluble vitamins and fatty acids, corticosteroid hormones, and mediators of electron transport and an important dietary energy source. Alcohol Source of calories only--no nutritional value. Water (b) Approximately 60% of the total body mass in a normal adult. Provides a medium for the solubilization and passage of nutrients. Also serves as the medium in which intracellular metabolic reactions take place. (a) Serving sizes based on USDA Dietary Guidelines for Americans. (b) Water content in foods varies greatly. Many foods, especially fruits and vegetables, can be good sources of fluid.
Accepted May 21, 2004.
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The use of diet and nutritional supplements as a way to enhance health prevent disease.
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as a missionary he fearlessly confronts the “perils of waters, of robbers, in the city, in the wilderness.” [N.T.: II Cor. 11:26]
See : Bravery , West Publishing Company, 1990.
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Kinetics (classical mechanics)
That part of classical mechanics which deals with the relation between the motions of material bodies and the forces acting upon them. , 2000.
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1. Australian Institute of Sport (http://www.ais.org.au). Includes resources, research, hot topics, and supplements links. Nutrition issues for many specific sports are discussed.
2. Sports, Cardiovascular and Wellness Nutritionists (SCAN) (http://www.nutrifit.org). SCAN is a practice group of the American Dietetic Association.
3. The Gatorade Sports Science Sports science is a discipline that studies the application of scientific principles and techniques with the aim of improving sporting performance. Human movement is a related scientific discipline that studies human movement in all contexts including that of sport. Institute (http://www.gssiweb.com). Although there are some commercial aspects to this site, the Sports Science Center link presents excellent scientific and sport-specific information.
4. University of Illinois University of Illinois may refer to:
Tracy R. Ray, MD, Rachel Fowler, MS, RD
From the American Sports Medicine sports medicine, branch of medicine concerned with physical fitness and with the treatment and prevention of injuries and other disorders related to sports. Knee, leg, back, and shoulder injuries; stiffness and pain in joints; tendinitis; "tennis elbow"; and Institute and the Alabama Sports Medicine and Orthopaedic Center, Birmingham, AL.
Reprint requests to Tracy R. Ray, MD, Alabama Sports Medicine and Orthopaedic Center, 1201 11th Avenue South, Suite 200, Birmingham, AL 35205. Email: email@example.com