Please note that this page is designed to provide you with basic knowledge in nutrition and is an introduction only.
If you would like any further information you should contact a nutritionalist.
Please look at bottom of this page for guidance.
Food is the fuel we need to provide energy for the body to function. This fuel must be of the correct mix to supply the body with the essential nutrients to function properly.
Whilst the body may be able to compensate for certain nutritional deficiencies, the harder the athlete trains the more likely they are to suffer from ailments and fatigue, or at the very least, poor performance.
Nutrition is the term used to describe the intake of nutrients necessary to carry out the functions which maintain a healthy body and provide energy for the working muscles.
DIET.
Diet may be described as our pattern of food consumption showing individual nutrient intake.
FOOD.
The food we eat contains various nutrients which are listed and described below. The balance contained in each food varies widely and it is therefore important we eat a range of different foods as well as recognizing how to alter this balance to match the particular demands we make on the body at any given time.
The body requires food for three main functions.
1. ENERGY.
Almost every function performed by the body requires energy which is produced by splitting of a chemical called ATP (adenosine triphosphate). The foods which contribute to the production of ATP are:
Carbohydrates.
Fats.
Proteins.
As we are not able to store large amounts of ATP in our cells, fat and carbohydrate are stored within the liver, blood and muscles. These foods are then readily available to be broken down when required.
Energy is measured in kilojoules (kj) and kilocalories (kcal) and is the measurement of heat generated from the different foods.
To convert kcal to kj multiply the number of kcal by 4.2.
The amounts of energy which may be generated from each nutrient varies considerably, and nutrients such as vitamins and minerals do not yield any energy at all.
2. GROWTH AND REPAIR.
Proteins.
Trace elements.
Water.
3. REGULATING BODY PROCESSES.
Vitamins.
Trace elements.
Water.
Some Proteins.
CARBOHYDRATES.
Carbohydrates are our most readily convertible and therefore effective form of energy and exist in two main forms: -
Complex Carbohydrates - Also referred to as starch foods.
Simple Carbohydrates - Also referred to as sugar foods.
Carbohydrates (CHO) are consumed in our day to day diet, albeit as starches and sugars. We take CHO in, they are broken down and stored in our liver and muscles as GLYCOGEN whilst in our blood as GLUCOSE. This is where it remains until it is utilized by the body in energy production.
The body can quickly convert CHO to glucose, whereas it takes longer to derive glucose from other nutrients such as fats and proteins. In order to ensure there are sufficient reserves of readily available glucose for our energy demands during exercise, we must obtain a plentiful supply of carbohydrates in our diet to provide the body with the energy it needs.
Complex CHO are good sources of energy. The less refined the better. The advantage of complex CHO is that these foods also contain other important nutrients such as vitamins, minerals, protein and dietary fibre.
During low intensity exercise such as walking or jogging the energy is a mixture of CHO and fats (see next section). Once the rate of exercise is increased to more explosive activities, the only energy source which may be utilized quickly enough is from CHO. Therefore no matter what exercise you are doing, the body will always require CHO for energy, and the harder you train, the faster you will deplete your glycogen stores. It also follows that the body must be allowed sufficient time to rest and replenish these stores before repeated exercise.
Fats contain the same 3 elements as carbohydrates; carbon, oxygen and hydrogen, but formed in a different structure. Although they have a much higher ratio of energy content to weight, fats are less easily digested and are known to have other more harmful properties. They are strongly linked to the increased risk of heart disease due to the high intake of saturated fats. our intake of unsaturated fats is normally proportionately lower. Because fats are not digested so easily, their consumption should be limited and certainly not included in a pre- competition meal.
EXAMPLES OF FATS.
UNSATURATED.
Some vegetable oils (sunflower oil, olive oil and rice oil), polyunsaturated margarine, nuts (not cashew or coconut).
As a quide, saturated fats are normally solid at room temperature and tend to be animal fats. Most unsaturated fats are liquid at room temperature and are usually vegetable fats.
PROTEINS.
Proteins are used mainly for building and repairing tissues, and are the least efficient energy source. Protein is only used as an energy source when other energy sources are low. CHO and fats should be maintained and utilized for energy production.
Beans, baked beans, nuts and seeds, bread, potatoes, cereals, pasta.
FLUID INTAKE.
Water is an extremely important nutrient, and essential to the functioning of the body and its cells. It forms a large part of most of the cells in the body, transports other nutrients to the cells, removes waste products from tissues, regulates temperature and performs numerios other functions. As heat is produced by muscles during exercise, temperature regulation plays a crucial role especially for the sports person and obtaining the right liquid intake may be essential to their optimum performance. The athlete must maintain a reasonably stable temperature and fluid content to help achieve their best. An increase in temperature, or a very small loss of water will seriously impair their ability to exercise.
It is especially important for endurance athletes or sportspeople who are active for long periods to begin exercise with sufficient body fluid, and to continue replenishing small amounts of water during exercise -- WAITING UNTIL YOU ARE THIRSTY IS TOO LATE.
During competition, particularly on a windy cool day, you may not notice sweating at all, and may feel quite cool as the sweat will evaporate more quickly.
YOU MUST TAKE REGULAR SMALL AMOUNTS OF WATER.
A good indicator of fluid concentration in the body is the color of the athletes urine (the pee test). The athlete should have urine almost as clear as water before exercise: darker colored urine indicates low water content in the tissue cells.
Dehydration of as little as 1% of bodyweight may significantly reduce performance capacity.
HOW TO CONSUME ADEQUATE QUANTITIES OF FLUID.
During training and over matches and competitions it is vital to monitor your state of hydration. The following checks will help you.
1. WEIGHT - 1 kg of weight lost over a training session is equivalent to 1 litre of fluid lost.
2. THE "PEE" TEST - Small volumes of dark colored urine indicate the need to drink. regular visits to the toilet producing copious quantities of relatively clear colored urine indicates that you are hydrated.
3. THIRST - Thirst is an unreliable indicator of the need to drink. By the time you are thirsty you are already partly dehydrated. If you finish a training session and you are thirsty you have not taken enough fluid on board during the session. Whenever you become thirsty start to drink IMMEDIATELY. Preferable, drink before you are thirsty.
GUIDANCE.
Sound nutrition is essential for sporting success of all ages.
A sound diet for non-sporting people should consist of --
CHO 50%
FAT 30-35%
PROTEIN 15-20%
HOWEVER Sports people need more energy to support their training and competing in matches. It is important that this energy comes from increasing the CHO intake rather than from eating more fat and protein. Sportspeople should get as much as 60-70% of their energy from CHO.
With active sportspeople, the energy requirements are best met from the following ---
CHO 60-70%
FAT 20-30%
PROTEIN 10-15%
The energy expended (kcals) for various sports are ---
A football match = 800
A squash game = 650
A tennis game = 440
A swimming session = 600
Jogging = 230
A 100m sprint = 20
SPORT DURATION APPROX ENERGY USED
Football 90 Mins 9kcal/min
Squash 45 Mins 10-18kcals/min
Tennis 60 mins 6-9kcals/min
Jogging 30 mins 7-8kcals/min
Sprinting 15-20 secs 99kcals/min
CARBOHYDRATE CONTENT OF FOOD.
FOODCARBOHYDRATE CONTENT
1 Large portion of spaghetti 90g
1 can of glucose drink (330ml) 64g
1 large portion of rice 60g
1 large jacket potato 45g
1 large tin of baked beans 45g
2 large thin slices of bread 30g
1 pint of milk 30g
1 can of lucozade sport drink 23g
1 medium sized banana 20g
3 lucozade sport glucose tablets 10g
1 apple 10g
ENERGY INTAKE AFTER EXERCISE.
It is important to ensure that a sportsperson's post event meal contains high amounts of CHO so that glycogen levels are quickly restored and stores are built up for the next game.
Glycogen is restored to the muscles at a rate of 5% per hour. It takes 20 hours to fully replenish the stock. However, during the first 2 hours after exercise, glycogen is restored at a faster rate at 7%
It is therefore, recommended that sportspeople eat or drink carbohydrate as soon after exercise as possible to make sure that maximum restoration is taking place.
The quantity or type of carbohydrate appears to make little difference, so long as the total amount is replenished in the period. Eating 50 - 100 grams of CHO every 2 hours is suggested.
Sports people who train intensely for 60 - 90 minutes expand as much as 100 - 1400 calories. To replenish their normal glycogen on a daily basis they may need to increase their CHO intake by at least 500 grams. A suggested routine is to eat 10 grams of CHO per kilogram bodyweight per day
Until recently George Johnson was the first team physiotherapist for Gillingham Football Club (a professional Football Club in the English Football League) and the England Hardball Hockey Team. He is a member of the Chartered Society of Physiotherapy as well as The Association of Chartered Physiotherapist in Sports Medicine, The World Federation of Athletic Therapist and Trainers, World Federation of Sports Physiotherapist, Society of Sports Therapy, member of the Physiotherapy Pain Association, member of the Independent Professional Therapists International. Is a UK Athletics recommended practioner and is Registered with the Health Professions Council. He has strong ties with a number of local sports clubs and is a supporter of FANS ( Free Admission for National Sportspeople). Among his clients, past and present, are international athletes, footballers, boxers, professional squash players, golfers, tennis players and many more people, from all sports, of all ages and all walks of life. PHONE GEORGE NOW ON 01227 366648 OR 07742716379 For a quick appointment at a time to suit you, or simply send him an email.
