Sports Nutrition PDF

Sports Nutrition Athlete ---------- person who participates in sport Exercise physiology ---------- science of the response and adaptation of bodily systems to the challenge imposed by movement i.e., physical activity, exercise, and sport Nutrition ---------- science of the ingestion, digestion, ab...

Sports Nutrition Athlete ---------- person who participates in sport Exercise physiology ---------- science of the response and adaptation of bodily systems to the challenge imposed by movement i.e., physical activity, exercise, and sport Nutrition ---------- science of the ingestion, digestion, absorption, and metabolism of nutrients and their biochemical functions Physical activity ---------- bodily movement that results in an increase in energy expenditure above resting levels Exercise --------- physical activity that is planned, structured, repetitive, and purposive in the sense that improvement or maintenance of one or more components of physical fitness  Exercise may be described an aerobic or anaerobic Aerobic means “with oxygen” and is used in reference to exercise or activity that primarily uses the oxygen-dependent energy system i.e., oxidative phosphorylation  Aerobic activities can be sustained for a prolonged period of time and are referred to as endurance activities and those who engage in them are referred to as endurance athletes Eg. Running or jogging , Biking , Swimming , Walking , Hiking , Anaerobic means “without oxygen”  Is used in reference to exercise that primarily uses one or both of the energy systems that are not dependent on oxygen i.e., creatine phosphate or anaerobic glycolysis  These types of activities are short in duration and high in intensity  Athletes in high intensity, short duration sports are called strength athletes Eg. Sprinting , Jumping , Heavy weight lifting , Resistance band exercises , Bodyweight exercises (e.g. push-ups, pull-ups, Training ------------- A planned program of exercise with the goal of improving or maintaining athletic performance Sports ----------- Game, competition, or activity needing physical effort and skill that is played or done according to rules, for enjoyment and/or as a job Sports nutrition ---------- The application of nutrition and exercise physiology principles to support and enhance training. Energy --------- Capacity to do work “or” In the context of dietary intake, defined as the caloric content of a food or beverage Intensity ---------- Absolute or relative difficulty of physical activity or exercise Cardiovascular fitness ---------- Ability to perform endurance-type Training and Nutrition Goals Main goal for any athlete is to improve performance Improvements in sport performance can come as a result of factors like:  skill enhancement  psychological changes  specialized equipment  clothing  physiological improvements due to training General training goals are:  Improving performance  Improving specific components of fitness  Avoiding injury and overtraining  Achieving top performance for selected events Long-term nutrition goals are formulated to  support training  provide adequate recovery  maintain the immune system  support overall health Long-term sports nutrition goals:  Adequate energy intake to meet the energy demands of training  Adequate replenishment of muscle and liver glycogen with dietary carbohydrates  Adequate protein intake for growth and repair of tissue, particularly muscle  Adequate overall diet (e.g., proteins, antioxidant, vitamins) to maintain a Short-term sports nutrition goals: Consumption of food and beverages to delay fatigue during training and competition Minimization of dehydration and hypohydration during exercise Utilization of dietary strategies known to be beneficial for performance, such as pre-competition meal, caffeine intake, or carbohydrate loading  Athletes who train hard, deplete nutrient stores and are at risk for frequent and repeated infections, short term nutrition goals Basic Training And Nutrition Principles Principle of Progressive Overload  Adaptation occurs as a result of stimulus that stresses the body  Stimulus must be of sufficient magnitude to cause enough stress to warrant longer-term changes by the body  Stimulus of this magnitude is called overload  If exposed to an overload stimulus repeatedly, the body will adapt over time to that level of stimulus  For further adaptation to occur, the overload stimulus must be progressively increased Principle of Individuality  While general training principles apply to all people, individuals may respond and adapt slightly differently, even when exposed to the same training stimulus  Two similar athletes that follow the same strength-training program will both improve their strength, but it is likely that the amount and rate of change in strength will be slightly different  Individual differences must be taken into account when considering an athlete’s training program Principle of Specificity  Type of physiological responses and eventual adaptations will be specific to the type of stimulus and stress imposed on the body  Aerobic exercise will result primarily in cardiovascular adaptations and strength training will result in neuromuscular adaptations  Effect, intensity and duration of aerobic exercise may have changes in energy system pathways such as carbohydrate and fat metabolism  One of the primary goals of sports nutrition is to support training, so nutrition recommendations for athletes must be specific to their sport or training focus  Dietary recommendations for those who train primarily for strength and power are different from recommendations for athletes who train Principle of Hard/Easy  Stimulus part of training receives the most attention, but often neglected are the rest and recovery that are required for the adaptation to occur  Training programs are designed so that hard physical efforts are followed by training sessions with less physical stress to allow for the rest necessary for optimal adaptation  Training principles have applications to nutrition  After hard training sessions where muscle glycogen is nearly depleted, athletes recognize that they must eat a large amount of carbohydrates to replenish the carbohydrate-depleted muscles  Amount of muscle glycogen used during an easy workout is much less -------------------- while carbohydrate intake is still important after an easy Principle of Periodization  Adhering to the principle of specificity, training programs are also often arranged in time periods according to the specific adaptation that is sought For example, competitive long distance runners may spend a portion of their yearly training time concentrating on running longer distances to improve their maximal aerobic capacity and endurance, and another portion of their training time running shorter distances at higher intensity to improve their speed  Within this principle of periodization, training programs are generally arranged according to different time periods: Macrocycle  Is an overall time period that begins at the onset of training  Includes the time leading up to a specific athletic goal or competition  For an athlete seeking to peak at the annual national championships, the macrocycle may be a calendar year  Macrocycle may be longer (e.g., four years for an athlete concentrating on the Olympics) or shorter (e.g., six months for a distance runner training for a springtime marathon), depending upon the specific competitive goals of the athlete Mesocycle  Macrocycle is subdivided into time frames ----------- called mesocycles, each having a specific training purpose  As with the macrocycle, the mesocycles may be of varying lengths of time, depending upon the athlete’s goals, but typically are weeks or months in duration  Competitive distance runner may have a mesocycle focused on improving aerobic Microcycle  Each mesocycle is made up of repeated time intervals ----------- called microcycles  Microcycles are often designed to coincide with the weekly calendar, but can vary from the standard seven-day week, depending upon the athlete’s specific needs Example – Weekly training mileage for the competitive distance runner Principle of Disuse  As the body adapts positively in response to training stress, it can adapt negatively, or atrophy if stress is insufficient or absent  Athletes that have improved function through training can experience the loss of function, either intentionally for short periods (e.g., resting during the Specificity ------------ Training principle that stresses muscle in a manner similar to which they are to perform Periodization ---------- Dividing block of time into distinct periods. When applied to athletics, the creation of time periods with distinct training goals and a nutrition plan to support the training necessary to meet those goals Macrocycle -------------------- Athlete’s overall training period; often one year but may be longer or shorter Mesocycle ------------ Subdivision of the macrocycle; usually many weeks or a few months Microcycle ---------- Subdivision of the mesocycle and the smallest subdivision of the macrocycle; usually seven days but may be longer or shorter Volume ------------ Amount; when applied to exercise training, a term referring to the amount of exercise usually determined by the frequency and duration of activity Nutrition periodization -------- Creating a nutrition plan to support training that has been divided into distinct periods of time Basic Nutrition Standards And Guidelines Definitions of RDA and all Dietary guidelines My pyramid Basic Sports Nutrition Guidelines Energy  Calorie ----------- unit of energy which is defined by the amount of energy or heat it takes to increase the temperate of 1 gram of water by 1 degree Celsius  Ideally the average day-to-day diet should include the following nutrients:  Carbohydrates ------- key energy source  Fats ---------- another key energy source important in relation to fat soluble vitamins  Minerals ------------ inorganic elements which occur in the body  Proteins - needed for the growth and repair of muscles and body tissue  Roughage -------- the fibrous indigestible portion of our diet which is needed for a healthy digestive system  Vitamins ------------ water soluble and fat soluble vitamins are important in many of the body's chemical processes  Water --------------- carries other nutrients around the body and is required for normal Carbohydrates  Simple carbohydrates ----------- found in refined sugars and provide sweet taste, milk products, fruit and vegetables All of the sugars which one eat (whether they occur naturally or are added) are used by the body in the same way It is better to get simple carbs from foods in which they occur naturally as these foods also contain fibre and important nutrients  Complex carbohydrates ----------- found in grains such as bread, pasta and rice  Carbohydrates consume are converted into glucose ------------ form of sugar which is carried in the blood and delivered to the cells for energy  Glucose is broken down into water and carbon dioxide  Unused will be converted into glycogen ------------ another form of carbohydrate that is stored in the muscles and liver  Body is unable to hold more than around 350 grams of glycogen at one point, and once it has reached full capacity any excess glucose will be converted into fat Fats  Fat is an essential component of diet  Helps the body to absorb nutrients  Great source of energy which provides the body with essential fatty acids that it is unable to manufacture independently  Fats are important ----------- monitor how much to consume , as large amounts could lead to excess weight gain and could subsequently result in an increased risk of serious health concerns such as heart disease and high blood pressure  Fat contains both --------------- saturated and unsaturated fatty acids depending on the percentage of fatty acids present  Saturated fats ------------ found in animal products and processed foods such as meat, dairy and chips  solid at room temperature  does not contain double bonds between carbon atoms  not considered to be healthy for the heart and is known to raise your LDL (bad) cholesterol levels  Unsaturated fats -------------- found in foods such as olives, nuts and oily fish  liquid at room temperature and contain double bonds  considered to be heart healthy  work to lower your LDL cholesterol levels as well as raising your HDL (good) cholesterol levels Protein  Present in every cell of the body  Important for helping to build and repair tissues  Used to make enzymes, hormones and a variety of additional body chemicals as well as forming the building blocks of bones, muscles, cartilage, skin and blood.  Unlike fat and carbohydrates, the body has nowhere to store protein for when it requires a new supply  Protein foods include meat, fish, eggs, pulses, nuts, seeds and soya products High protein diets  Most high protein diets involve a high intake of protein and a moderate to low intake of carbohydrates  Many athletes and sports enthusiasts believe they need a diet which is high in protein in order to fuel their muscle growth, though most scientific research does not support this notion  Glycogen is energy which is stored within the body and used as fuel during exercise also help to maintain water  Some long distance athletes will use a technique known as carbo- loading, which essentially means they stock up on carbohydrates to increase the amount of glycogen available for a long event  Depletion in glycogen can mean that endurance athletes run out of fuel so it is unlikely that significantly reducing carbohydrate intake is going to improve sporting performance  Many endurance athletes know that a high carbohydrate and low fat diet is a good option for them, many strength athletes still adhere to a low carbohydrate, high protein diet, believing that it will help them to build muscle  Research suggested that strength athletes require both carbohydrates and glycogen stored within the muscle  Extreme muscle contractions are actually fuelled heavily by carbohydrates -------- as both fat and protein are unable to meet the demands of high intensity physical activity  High protein diets have also become a popular weight loss method, with some research suggesting that protein has the ability to satisfy hunger for longer periods of time than fats and carbohydrates  Many individuals are also attracted to the prospect of significant initial weight loss, which occurs as a result of muscle glycogen depletion.  Experts are unsure of how protein is able to reduce appetite, though a popular theory is that Energy requirements for exercise  During exercise the body begin producing energy at a much faster rate than when it is resting  Heart will beat faster in order to pump blood more rapidly around the body, the lungs work harder, and muscles will begin to contract  All of this body will use up stored energy at a faster rate than normal, and for this reason, individuals such as athletes who are not trying to lose weight will need to consume extra food each day so that what they eat and what they burn remains in balance  Individuals who do lot of training should not use unhealthy foods, but should aim to increase portion sizes of carbohydrate rich foods like porridge, wholegrain pasta and brown rice, as carbohydrates will help to  Experts recommend that wait between one and four hours after meal until exercise -------------- this gives the body time to digest the food  The more one eat the longer the digestion process will take to set in  Expert state that average sized meal eaten no more than two hours before exercise provides the best results  Meal should contain some form of carbohydrate, low in fat and not contain too much protein as this may work to slow down stomach movements and could leave feeling uncomfortable  Staying well hydrated while exercising is extremely important  When the body's water content falls below it's normal level this can have an impact on performance  If exercising for longer than 30 minutes then one should be drinking fluid with doing it Supplements  Supplements are used to boost strength, performance and recovery Common sports supplements include the following: Creatine  Is a high-energy compound which helps to store and provide energy  Is produced within the body, occurs naturally in fish and meat  Is considered to be a 'legal steroid' and is used by athletes and sports men and women to increase muscle bulk  It is intended to help one train for longer and also to boost performance during frequent high-intensity exercise  Some research has suggested it may have undesirable effects on the digestive system and result in muscular and cardiovascular issues also Whey Protein  Whey protein is a natural protein present in milk, containing very little fat, carbohydrate or lactose  Is known as a naturally complete protein, meaning that it is made up of all of the essential amino acids which are needed in the average daily diet  Also contains branch chain of amino acids (BCAAs), which are the first ones to be used during intense training  Whey protein provides the body with these amino acids and in turn they assist with repairing and rebuilding lean muscle tissue  It is extremely easy to digest ----------- it is absorbed quickly and can provide instantaneous nourishment to the muscles Energy Drinks  Staying well hydrated during exercise and training is extremely important, and even a small amount of dehydration could be detrimental to performance levels  Drinking water is a good way of keeping one hydrated during exercise periods, and some individuals also opt for energy drinks, particularly those who undertake endurance events such as long distance running  Many energy drinks contain electrolytes such as sodium --------- help to stimulate thirst and encourage drinking, enhancing the body's ability to hold water  Carbohydrates contained in many energy drinks can provide individuals with extra energy which may be needed in the latter stages of training, Dietary Supplements Dietary Supplement Health and Education Act (DSHEA)  Passed in 1994  A dietary supplement is defined as a “vitamin, mineral, herb, botanical, amino acid, metabolite, constituent, extract, or a combination of any of these ingredients” (Food and Drug Administration, 1994)  This legislation also provides labeling guidelines but does not ensure safety or effectiveness  In mid 2007, quality standards were mandated by the FDA and also places supplements that have very different functions and safety profiles in the same category  Prior to 1994, botanicals and herbs were considered neither a food nor a Because the legal definition for a dietary supplement is so broad, it is further divide into three subcategories: 1)vitamins, minerals, and amino acids 2) botanicals 3)Herbals Botanicals  Are typically compounds that have been extracted from foods and concentrated  Have link to both food (i.e., original source) and medications (i.e., concentrated dose) Example, garlic contains allicin ------------ biologically active ingredient that Potency and Purity of Active Ingredients  Until mid-2007, DSHEA did not require the amount of an active ingredient in dietary supplement to be standardized, or the use of good manufacturing practices, so quality ranged from excellent to poor  Gurley, Gardner, and Hubbard (2000) tested the ephedrine (ephedra) content of 20 dietary supplements and compared it to the amount listed on the label. Half of the supplements varied by more than 20 percent, including one that contained none and one that contained 150 percent of the amount stated. Botanical and herbal supplements need standardization because the amount of active ingredient in the herb or plant varies substantially, depending on the harvest and manufacturing conditions  In the same study, the authors detected five dietary supplements that contained norpseudoephedrine  Some dietary supplements do contain substances banned by sports governing bodies, and athletes are subject to disqualification even if the banned substances are not listed on the label and were consumed unintentionally  Contamination of dietary supplements prompted the National Football League (NFL) and its players association to begin supplement certification program in 2004  Under this program, dietary supplement manufacturers can be certified by an independent testing organization ----------players can be confident Glycemic index (GI) Method of categorizing carbohydrate containing foods based on the body’s blood glucose response after carbohydrates ingestion, digestion, and absorption. The index is based on scores up to 100 Nutrient dense Food containing a relatively high amount of nutrients compared to the caloric content Disordered eating  Spectrum between normal eating and an eating disorder  Include symptoms and behaviours of eating disorders, but at a lesser frequency or lower level of severity  Include restrictive eating, compulsive eating, or irregular or inflexible Eating disorders A substantial deviation from normal eating, which meets established diagnostic criteria (e.g., anorexia nervosa, bulimia nervosa, anorexia athletica) Anorexia athletica - obsessive focus on low body weight, combined with a severe decrease in calorie intake and/or excessive involvement in physical exercise, aimed at decreasing or preserving low body mass index (BMI) Good Manufacturing Practices (GMP) Quality control procedures for the manufacture of products ingested by humans to ensure quality and purity Quackery  Is the practice of making false claims about health-related products, and some dietary supplements fall under this category  Many dietary supplements are sold using multilevel marketing (MLM), and unscrupulous distributors may exaggerate their value because they will be financially rewarded if sales increase  Consumers can reduce their risk for being a victim of quackery by critically evaluating products before purchasing them