The food we eat supplies the energy our bodies need for movement
Stored chemical energy
Force exerted on bones via tendon
Energy in food comes in 3 basic forms
The body uses a mix of all three sources for exercise, but: • CHO – major source for exercise of moderate to high intensity
• FATS – major source for rest and low intensity exercise • PROTEIN – only a minor source and last resort
• Carbohydrates are one of two of your body’s major sources of energy for growth, body maintenance, and activity.
• Carbohydrates are important because they maintain our body’s energy stores and give us energy for our working muscles.
• FUNCTION - Major source of muscle energy
• FUEL SOURCE - Mobilised as glucose
• STORED - As glycogen in muscles and liver. This can quickly be converted into glucose and used as energy in the muscles. Excess is stored as fat.
• ENERGY SOURCE – For short term high intensity and until glycogen stores are depleted.
1 gram of CHO has 16kj of energy.
There are 2 types of carbohydrates:
• Starches (complex carbohydrates)
• Sugars (simple carbohydrates)
Come from plants and the best sources are bread, cereal, grains, vegetables, legumes, corn, potatoes, roots, peas and seeds.
Starches are a good source of CHO as they are more complex and contain other important items eg vitamins and fibre.
Sugars are a very quick source of energy, however they do not last very long. CHO sources high in sugar, eg. sweets are often seen as empty calories and are not recommended as a predominant energy source. CARBOHYDRATES
• Milk and dairy
• Cane sugar
• Biscuits & cakes
• Fats provide energy and also form a layer of fatty tissue beneath the skin to conserve your body’s heat.
• Fats, like carbohydrates, are used by your body chiefly as a source of energy.
• There are three types of fat:
– Saturated fats
– Polyunsaturated fats
– Monounsaturated fats
• FUNCTION - Minor source of energy, insulation, protection of organs, help the absorption of fat soluble vitamins A, D, E
& K, used in structure of all cells and nervous tissue.
• FUEL SOURCE - Mobilised as fatty acids
• STORED - as triglycerides in adipose tissue under skin and around vital organs
• ENERGY SOURCE – At rest and low intensity and once glycogen stores are depleted.
1 gram of FAT has 37kj of energy
If fats contain twice as much energy per gram than CHO, why not use them as our primary energy source?
Glycogen is a much quicker and easier source of energy. Glycogen is much easier to break down into glucose to be used in energy production. It also requires less oxygen to produce.
SATURATED FAT SOURCES:
• Milk, cheese, cream, butter
• Egg yolk
UNSATURATED FAT SOURCES
• Soya beans
• FUNCTION - Proteins help to build and repair your body’s cells and tissues. They form enzymes that regulate chemical reactions, form hormones and important parts of the blood.
Very minor source of energy and is only used once all other sources are depleted.
• FUEL SOURCE – Mobilised as amino acids
• STORED – In muscles and liver, and then excess is stored as fat.
• ENERGY SOURCE – 1 gram of PROTEIN has 17kj of energy
• Peas and lentils
There are four other components to our food:
Vitamins, minerals and water are considered nutrients or food chemicals, whilst dietary fibre is just considered essential for good health. VITAMINS
• Act as regulators of chemical functioning in the body
• Are essential for healthy skin and