Nutrition: The Basics
Eating well and staying hydrated are just as important to your training plan as doing the right exercises at the right intensity and volume. The objective of a nutrition programme for strength training is to develop and maintain a body with appropriate lean muscle that has the reserves of strength, power, and endurance to meet the demands of daily life, training, and competition. The human body is a complex machine, but research has given us a good understanding of the role played by the various elements of nutrition in staying healthy, getting fit, and in gaining and losing weight.
Foods, calories, and body weight
The weight of your body is made up principally of your skeleton, organs, and the muscle, fat, and water that the body carries. Muscular development (though not the number of muscle fibres), body fat, bone density, and the amount of water can all be changed by training and diet.
The basic facts about weight loss and gain are simple. You gain weight if you take on board more calories than you burn; and you lose weight if you eat fewer calories than you need to fuel your basic body functions and exercise regimen.
Some foods contain many calories for a given weight (they are energy-dense), while others, such as dietary fibre or roughage, minerals, and vitamins, contain few or no calories but are still a necessary component of your diet.
1. Carbohydrate – 4 calories per gram (113 calories per ounce)
2. Protein – 4 calories per gram (113 calories per ounce)
3. Fat – 9 calories per gram (255 calories per ounce)
4. Water, vitamins, and minerals – zero calories value
PROPORTION OF MAIN NUTRIENTS
Carbohydrates are our main source of energy. Nutritionists once distinguished between simple carbohydrates – those found in table sugar, biscuits, fruits, and fruit juices – and complex carbohydrates, found in bread, pasta, potatoes, rice, and whole-grain foods. The advice was to eat more complex and fewer simple carbohydrates because complex carbohydrates took longer to break down and absorb and so led to fewer peaks and troughs in levels of blood sugar.
However, the relationship between carbohydrate intake and the effect on blood sugar turned out to be a little more complex. Today it is more common to refer to foods as having a high or low glycaemic index (Gl). Gl is a measure of the effect that a particular carbohydrate has on blood sugar levels. Low Gl foods release their energy more slowly (preventing the feeling of “sugar rush”) and are believed to have other health benefits.
Dietary fat is a rich source of energy as well as an essential nutrient. It enables your body to absorb some vitamins and is important for proper growth development, and health. Fat gives food much of its taste and helps you feel “full”.
Not all fats are the same and most foods contain a combination of several fats. Unsaturated fats, such as those found in oily fish, and some vegetable and nut oils are more beneficial than the saturated fats found in meat and animal products, such as butter and lard. Saturated fat in large quantities is implicated in the development of coronary heart disease and needs to be kept to the minimum in a healthy diet. Eating too much fat of any kind will lead to an increase in weight.
The building blocks of the human body, proteins are essential to the growth and repair of muscles and other body tissues. We all need protein, and competing athletes may need a little more than sedentary people because intense training places demands on the ability of the body to repair itself. Proteins are made up of chemical units called amino acids, and foods such as fish, meat, and eggs provide a complete source of the essential amino acids. Fruit, vegetables, and nuts contain protein, but on their own may not supply all the amino acids needed by an athlete in training. For this reason, vegetarian and vegan athletes should take nutritional advice before embarking on high-level training.
Protein needs to be taken in regularly because it is not readily stored by the body. However, the daily amount of protein needed – even by a competing athlete – may be within the range of a “normal” healthy diet.
Vitamins are biologically active compounds used in the chemical processes that make the human body function. Vitamins are needed only in tiny amounts and come in two types – those soluble in fat and those soluble in water (which need to regularly replenished).
Minerals such as potassium, sodium, calcium, zinc, and iron are involved in many biochemical processes that maintain life and fuel growth. Mineral deficiency is rare in a balanced diet.
Water is crucial in maintaining health. The human body is composed largely of water and it is the medium in which most of the body’s chemistry is played out. Dehydration is potentially a very serious condition and in extreme cases can lead to death.
PROPORTIONS OF MAIN NUTRIENTS IN THE DIET
There is no universally “correct” balance of daily nutrient intake; the proportions of the main nutrients you need depends on your individual characteristics and lifestyle. However, the following figures are a useful reference point:
- 60% carbohydrate
- 25% fat
- 15% protein