First, what is metabolism? A simple definition is the sum of the processes by which the body acquires and uses the nutrients and energy required for life’s growth and maturation.
That translated into even simpler language means that metabolism is all the chemical reactions that go on in the body. (Every part of the body has a constant series of reactions occurring in it every moment of the day, however for our purposes, the main areas of interest are in the liver, which is the body’s ‘chemical factory,’ and the muscles where the energy produced by these reactions is converted into work.
There Are Two Types of Metabolism
Metabolism can be divided into two types: Anabolism – the constructive processes by which nutritive substances are transformed into complex living matter, i.e., growth.
And Catabolism – the process by which complex living matter is reduced to simple substances (breakdown of body tissue)
Metabolic rate is the speed at which the above process occur; a slow rate means the processes are taking over, a fast rate means there are rapid chemical reactions.
Metabolism Controlled By 4 Variable Factors
The processes of metabolism can be controlled by four variable factors.
1. Genetic
Genetic inheritance determines the nature of the structural and functional elements in cells and controls the body’s ability to utilize substances it obtains from the environment, i.e., food.
This means that, within limits, your genetic make-up will be the ultimate restricting factor in your body’s development. Olympic champions are, to some extent, born because they have an inbuilt potential that can then be developed, just like top bodybuilders.
2. Intermediary
Intermediary metabolism is primarily about the way metabolic processes interact.
3. Regulation
Regulation of cellular and organ interrelationships, particularly by the endocrine system (hormones), integrates tissue activities in a way that is conducive to health.
Chemical reactions in the body are largely controlled by compounds that circulate in the blood and are known as hormones. Hormones are produced by glands in the body called endocrine glands, of which the thyroid and pituitary glands are of greatest interest.
4. Nutrition
Nutrition is the last factor that determines metabolism, as it influences how the body utilizes food.
I think it would be very helpful if we looked at the way in which the above factors interact in the case of the pituitary gland, thyroid gland, and metabolic rate. I want to try to keep it simple but it should help illustrate a few points.
Thyroid Gland
The thyroid gland is located in the neck, on either side of the windpipe. It produces the hormone thyroxine and regulates the body’s metabolic rate within narrow limits.
Everyone’s blood thyroxine level is the same, ranging between 4 and 11mg per 100 ml of blood. People at the higher end of the scale have slightly faster metabolic rates than people at the lower level.
However, this does not mean that people with the same levels will have the same metabolic rates because, due to genetics, no two people have exactly the same reaction to the same amount of hormone.
There is no way you can alter the amount of thyroxine your thyroid is producing or the effect it will have on your metabolic rate, as these are genetically determined factors.
Pituitary Gland
The level of thyroxine in the blood is monitored by the pituitary gland – situated at the base of the brain – and if the level is found to be low, the thyroid is instructed to produce more thyroxine by a chemical ‘messenger’ known as the thyroid stimulating hormone. This process helps keep the body’s metabolic rate constant.
In order for the thyroid to produce thyroxine it needs a constant supple of iodine in the diet, as iodine is essential to the formation of the hormone. Not enough iodine means a swelling of glands or goitre can occur.
Metabolism and BodyBuilding
Three types of problems always pop up when talking about how metabolism affects bodybuilders, and we’ll deal with them separately.
1. The person who wants to maximize his metabolic rate to maximize his anabolic gains. To maximize growth, certain factors must be present
– a) A sufficient supply of basic nutrients in the diet – protein, fat, carbohydrates, vitamins, and minerals. If the basic building blocks aren’t present, then no amount of stimulation of the metabolism through training will produce results.
– b) A rigorous training program (anaerobic)
– c) A program of aerobic training to stimulate metabolism, i.e., jogging, swimming, cycling. Weight training is anaerobic and does not stimulate the metabolic rate to the same extent as aerobic training.
– d) The use of drugs to increase anabolic rate is to be discouraged as the dangers involved are considerable. A sample menu that contains sufficient calories with about 130-140grams of protein should workwell.
Sample High Protein Diet
Breakfast – fruit – 1 orange or 1/2 a grapefruit. Cereal with milk and sugar. Eggs 2, bread 1 slice, butter or enriched margarine, a beverage with cream and sugar 1 cup.
Midmorning – milk 8oz,
Lunch – meat or equivalent 120g. Potato, rice, dry beans, or spaghetti 100g. Salad 100g, bread 1 slice, butter or enriched margarine, fruit, milk 8oz.
Dinner – meat, fish, turkey, chicken, 120g. Potatoe 100g. Vegetable 100g. Bread 1 slice, butter, or enriched margarine.
Dessert – milk 8oz
Bedtime – Eggnog with milk
2. The Under Weight Person has a different problem – he wants to build muscle mass. He must do this by providing sufficient nutrients to supply the body’s needs and then diverting excess nutrients into protein production rather than storage as fat.
He needs a high-protein diet such as above but also a high-calorie diet. Training to develop the anabolic effect and increase metabolism is also essential, both aerobic and anaerobic. High-energy foods should also include milk and milk products, candies, cakes, puddings, meats, and alcoholic beverages. Not a bad diet, you may think!
Supplementary vitamins may be desirable. If sufficient aerobic and weight training is done, overweight should be avoided, but it will still be a long, hard build-up.
3. For the overweight person who wants reduction – stimulation of metabolism by aerobic exercise is important. The aim is to maintain muscle mass while reducing fat.
The body must be forced to use excess fat for energy production, so dietary calorie intake must be reduced to,on average, around 1200 calories a day. Below is a sample menu that has been successful for reducing.
Sample 1200 K cal Reducing Diet
% Grammes Kilo Calories
Protein 20 60 240
Fat 35 47 420
Carbs 45 135 540
Total 1200
Breakfast – 1/2 cup orange juice, 1 egg (poached or boiled) or 10z dry cereal (not presweetened) enriched white or wholemeal, 1 tablespoon margarine. 4oz skimmed milk (1/2 cup) coffee or tea without cream or sugar.
Lunch – 4oz lean meat, fish, poltery or cottage cheese, 1 slice of bread or roll, 1 tablespoon margarine, 1 tomato and lettuce salad, 1 teaspoon mayonayse, 4oz (1/2 cup) skimmed milk, coffee or tea, without milk or sugar.
Mid-afternoon – 6oz tomato juice, 1 apple or pear, 4oz skim milk.
Dinner – 6oz lean meat, fish or poultry, 4oz carrots or peas, 4oz broccoli, cabbage or spinage, 1/2 cup of berries or 2oz wedge of melon, coffee or tea if desired (no cream or sugar)
Evening – 6oz tomato juice or mixed vegetable juice, 4oz (1/2 cup) skimmed milk.
The above suggestions are generally applicable. Howevr for a person on a pre-contest diet,an individual approach would be preferable. To be succesfulin this requires much study and application. I f you study the subject more it will pay long term dividends to competitors who are willing to devote some time to carful consideration the factors involved, and to ignore the pseudo scientific nonsencewhich is so widespread.
References & Excerpts
Author: Dr. Guy Wright, M.B..Ch.B. BodyPower Magazine
