We take a closer look at understanding the components of Nutrition basics as well as looking at applicable scenarios to what you want to achieve. Aside from training, nutrition is the most important influence on athletic performance.
- Before exercise and Carboloading
- During exercise / event
- After exercise or an event
- Using the Fast Fuel range for maximuim results
There are essentially three main nutrients that provide energy to our bodies, namely PROTEIN, CARBOHYDRATE and FAT. Food consists of a combination of these nutrients. There are very few foods that consist entirely of one single nutrient, although some may well be higher in certain nutrients than others. Some foods are also rich sources of VITAMINS and MINERALS, however although these nutrients are essential they do not contribute any energy to the diet.
Your body requires energy for growth, muscular activity and basic body functions. The amount of energy you require will depend on factors such as your weight, activity, age, sex and presence of illness. The actual amount of energy expended during a particular activity depends on the intensity and the duration of that particular activity.
Different foods provide different amounts of energy depending on how much protein, carbohydrate and fat they provide. Energy can be measured in either kilojoules (kJ) or another term is calories (kcal).
Carbohydrate is the fuel of choice for endurance training. Carbohydrate is the first source of glucose for the exercising muscle and it comes from the glycogen store (found in liver and muscle) in the body. It is also the most efficient fuel with respect to oxygen consumption. The problem that arises is that available carbohydrate from the glycogen store is limited. When this store of glucose is depleted the liver controls the breakdown of either protein or fatty acids into glucose for further energy. Exhaustion is usually correlated with depletion of glycogen stores and the consequent failure to provide enough blood glucose for the exercising muscle.
Depletion is common during a long distance event or even after a few consecutive days of heavy training when the time between training is insufficient for the glycogen stores to be synthesized. This situation, where even the smallest amount of exercise can cause fatigue, can be avoided by increasing dietary carbohydrate and by timing the intake of carbohydrate to improve its availability. Every gram of carbohydrate provides 17 kl (4 kcal) and should be the main source of energy in your diet. By providing sufficient carbohydrate as an energy source, one will also spare protein for its other more important roles in the body. Very low carbohydrate diets should therefore not be encouraged for this reason. Most athletes should consume a diet where 50-70% of the total energy comes from carbohydrates to ensure maximum repletion of glycogen stores. This can amount to about 500-600g of carbohydrate a day.
The main carbohydrate sources in the diet are sugars and starches. Sugars are generally very quickly and easily absorbed from the gut, while starches take a little longer as they require more digestion. Starches are ''complex'' carbohydrate sources, which also contribute other nutrients such as fibre (roughage), essential vitamins (especially vitamin B complex) and minerals, while sugar as such provides little other nutrition.
Sugar (any type) in the diet provides energy in the form of refined carbohydrate, but little else! Unless you require the extra energy in this concentrated form, it is therefore wiser to rather chose complex carbohydrates which will also provide you with other nutrients. However, there is no reason why you should not be allowed a certain amount of sugar in the diet, providing you are not a diabetic or overweight. Foods with a high sugar content include: sugar (all types - white, brown, castor, icing), jam, marmalade, honey, syrup, sweets, chocolates, condensed milk, puddings, ice cream, cool drinks, sweet biscuits, cakes.
Starches such as breads and cereals, rice, pasta and potatoes are all complex carbohydrate sources. Fibre in the diet has been shown to have many favourable roles such as cancer prevention, lowering cholesterol and blood glucose, etc. From all the evidence that exists it would therefore seem wise to advocate a high fibre diet with complex carbohydrate sources providing the bulk of the energy in the diet. Unrefined complex carbohydrates included foods such as: whole-wheat bread, bran cereals, brown rice, potato with the skin, oats, barley, samp, beans and mealies.
It has always been believed that additional protein among athletes is needed to increase strength and to enhance performance. Protein is an important energy source during events of long duration in which the availability of muscle glycogen becomes a significant factor. The proportion of energy requirement supplied by protein has in estimated at 5-20% depending on whether the glycogen stores are optimal or deplete before commencing the exercise.
Every gram of protein provides 17 kJ (4 kcal). Protein is essential for building, maintaining and repairing tissue and this may be particularly relevant for endurance athletes who have damaged muscles. For this reason it plays a vital role in growth and development. The quality of different proteins also varies, with some being of a higher quality in that they provide all the protein components and are therefore termed complete proteins. Good sources of protein include foods such as meat, poultry, fish, seafood, milk, eggs, cheese, yoghurt, peanut butter, nuts, dried beans and peas (split peas) and lentils.
Fat is the fuel best suited for low to moderate activity because of its extensive availability in adipose stores.
Free fatty acids are released from adipose stores during prolonged exercise, for uptake by the muscles for fuel. This does not necessarily mean that the diet should be high in this nutrient. The prudent diet recommendation of fat being 30% of the total energy is sufficient for the athlete. Every gram of fat provides 38 kl (9 kcal). In other words, fat provides more than twice the energy of either protein or carbohydrate. From this it can be seen that too much fat in the diet can easily lead to weight gain, since a high fat diet will substantially increase your energy intake. Besides this, a high dietary fat intake has also been linked to diseases such as heart disease and cancer.
Although the amount of fat one eats is important the type of fat is also very significant. For example, saturated fat (mainly animal fat sources), has been found to raise blood cholesterol, while unsaturated fats can help lower cholesterol provided it is taken in the correct amounts. As with protein there are certain fats (essential fatty acids) that cannot be manufactured by the body and must therefore be consumed in the diet. These fats can be obtained from a variety of sources of which fat from a vegetable origin is healthier. Rich sources of fat include: oil (all types), margarine, butter, cream, mayonnaise, red meat, egg yolk, chicken skin, full cream milk full cream cheese (cheddar, sweetmilk, etc.), avocados, olives, nuts and seeds.
Vitamins and Minerals
Although vitamins and minerals do not contribute any energy to the
Diet and occur in much smaller amounts, they are essential for survival as they perform vital functions in the body. They are scattered throughout different foods, occurring more in some than in others. By choosing a wide variety of different foods in your diet you should ensure that you obtain all your necessary requirements. It has always been assumed that if the athlete meets the increased requirements for energy that they would also satisfy all there vitamin and mineral requirements as well. Although this may be true in some cases, some athletes may develop deficiencies because of there unhealthy eating habits. It is also important to remember that certain vitamins and minerals are potentially harmful in the incorrect doses. There are however two minerals that could lead to potential problems
Iron is a component of haemoglobin which is instrumental in the transport of oxygen from the lungs to the tissues.
Is fulfils a similar role in myoglobin, which act within the muscle as an oxygen acceptor. Iron is also involved in the production of ATP (energy). It thus follows that iron deficiency anaemia limits the aerobic endurance and the capacity to do work. Athletes who are particularly at risk for developing low iron stores are the rapidly growing male adolescent. females with heavy menstrual losses, athletes consuming energy restricted diets, distance runners who may have increased gastrointestinal iron losses and those training in hot climates with heavy sweating.
The best sources of iron are found in any meat (beef, mutton or pork), poultry or fish, cocoa powder, dark green leafy vegetables (spinach, broccoli, peas and sweet potato), dried beans, dried fruit (apricots, peaches, prunes, raisins), egg yolk, fish paste, iron fortified puffed corn and puffed rice, legumes (dried peas and beans), liver, kidney and vegetable extracts (Bovril, marmite), molasses, nuts (peanuts and peanut butter), shellfish whole wheat bread and cereals.
Many female athletes who maintain a low body weight are at a high risk of becoming amenorrheic. Those athletes are generally gymnasts, long distance runners and dancers. Amennorrhea results in a reduction in bone mineral content and therefore the athletes should be encouraged to increase their dietary intake of calcium. Good sources of calcium include all dairy products, green leafy vegetables, nuts (particularly almonds) and fish with bones eg.
Glycogen loading (carbo loading)
Swedish physiologists discovered that the duration of intense, prolonged aerobic exercise is limited by the extent of muscle glycogen stores. They experimented with dietary manipulation and appropriate training and concluded that correct dietary manipulation could result in an increase of glycogen storage.
The following regimen should be followed and can result in an increase in glycogen stores of 20-40%.
= A long hard work out on the seventh day before the event.
= During the following four days the carbohydrate intake must be increased to 500-600g/day (50-70% of total energy). Training must be decreased during this period.
= No training or exercise on the day before the event.
After the event or a hard training session, it takes up to 12-24 hours to fully top-up your body's glycogen stores and 48 hours for supercompensation of the stores. Carbohydrate intake immediately after a training session or competition is very important because 60% of the total glycogen repletion occurs within the first 10 hours after depletion. Recommendations include a carbohydrate intake of 100 grams within 15-30 mins after the exercise, followed by an additional 100 gram feeding every 2-4 hours thereafter. It is important to remember that glycogen resynthesis is proportional to the amount of carbohydrate consulted.
Glycogen loading is only recommended for athletes participating in events that are one hour or longer. It may also be useful for athletes participating in several short events on the same day.
Creatine monohydrate is used in the muscle tissue for the production of phosphocreatine, a factor in the formation of ATP, the source of energy for muscle contraction and many other functions in the body.
Recent research has discovered that Creatine aids endurance athletes in the following 3 ways;
1. Providing an instant source of energy
2. Mopping up some of the fatigue-causing acid that builds up during high-intensity exercise
3. Directly stimulating muscle proteins to contract
Increasing ones Creatine reserves helps sustain a high-intensity burst for longer, it speeds recovery enabling you to repeat those bursts sooner.
There is no doubt that Creatine is of great benefit to power and strength athletes such as sprinters and weightlifters.
The benefits of Creatine result in:
1) Improving the quality of interval training
2) Increasing strength
3) Staving off injury