P3/P4 Energy Expenditure/ Energy Balance
Energy intake and Expenditure • It can be measured in either calories and joules. One calorie is defined as the amount of energy, or heat, needed to raise the temp of 1 litre of water by 1.c. In Britain we use calories, but should be referred to as Kilocalories or Kcal. The international unit for energy is joule or kilojoule 1kcal= 4.2 joules
Amount of Energy in foods • 1g carbs = 4 Kcals • 1g Proteins = 4 Kcals • 1g fat = 9kcals
Body Composition • The body is composed of two elements: • 1. Lean body tissue (ie. Muscles, organs, bones, blood) • 2. Body fat (or adipose tissue) • The proportion of these two components in the body is called body composition • This is more important than total weight
Calorimetry • This measures you’re BMR • Calorimetry is the science of measuring the heat of chemical reactions or physical changes. • Calorimetryinvolves the use of a calorimeter.
Direct Calorimetry • Directly measures energy produced by combination of food with oxygen • Involves the burning of food in a controlled way, and measuring heat energy produced • Heat energy is measured by observing the rise in temperature of a quantity of water heated by the burning food. • Alternative: Measure body’s heat production in a calorimeter chamber • The heat energy created by the subject radiates to the walls and heats the water. • Temperatures of incoming and outgoing water and air are recorded and used to calculate BMR and total energy expenditure.
In-direct calorimetry • Uses the fat that every atom of carbon in food combines with a molecule of oxygen during the chemical reaction to produce one molecule of carbon dioxide and release a definite and constant amount of energy. • Method involves the measurement of the amount of oxygen consumed – which can therefore be related to the amount of energy released by food
How much Energy (food) do you actually need? • Basal Metabolic Rate (BMR) is the minimal caloric requirement needed to sustain life in a resting state. This is the amount of energy that your body requires if you slept and rested all day. A variety of factors impact this affect the BMR, some speed it up and some slow it down they are; Body size: taller heavier individuals need a higher BMR to fuel them Growth: Children and Pregnant women need a higher BMR If you are ill (high temp) or stressed, you also require a higher BMR Age: The older you get the less you require Muscle mass: The more you have, the higher the BMR as lean tissue needs more energy that fat
BMR • To calculate your BMR you will need to follow this link; • http://www.myfitnesspal.com/tools/bmr-calculator • To work out your total expenditure throughout your day use this; • http://www.health-calc.com/diet/energy-expenditure-advanced
Energy balance • Energy is expended in a number of different ways such as resting metabolic rate, thermic effect of activity, • Your energy balance is the balance of calories consumed through eating and drinking compared to calories burned through physical activity. What you eat and drink is energy in. What you burn through physical activity is energy out.You burn a certain number of calories just by breathing air and digesting food. You also burn a certain number of calories through your daily routine.An important part of maintaining energy balance is the amount of physical activity that you do. People, who are physically active, burn more calories than people who are not as physically active.
Energy Balance • A sports person would want to be in balance when they are at their normal training day and not looking so massive gains. This is mainly referring to any sports person who wants to stay at their optimum weight.When they would want to make massive gains in their training they would want to increase the intake compared to the expenditure • When wanting to loose weight you need to take less in than you use up
Catabolic state • Catabolism refers to the breaking down of stuctures in the body. Training (especially in a gym) causing a lot of this due to the damage and stresses put on the muscles. You will often feel stiff and sore after training as your body is in a catabolic state. You need to ensure you replace the energy lost and aid the recovery/ repair process with your meals
Anabolic state • Post training meals, rest and recovery are when your body grows bigger and stronger. This is vital to any sports performance
Assessment task • Talk through the energy obtained from each type of food • How you assess body composition • How to measure you requirements (Calormetry) • Your BMR and activity contribution to energy requirements • Energy Balance and expenditure (Catabolic, Anabolic State)