3.1.2 – Diet

Learning objectives

To understand the 7 components of a balanced diet.

To describe how the body gets energy from carbohydrates, fats and proteins.

To be able to explain carbohydrate loading and the need for a high protein diet for some athletes.

To understand the terms ‘overweight’ and ‘underweight’

elgsuco

Clue: combines with OXYGEN to create energy

GLUCOSE

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msiple radrhyetcbod

Clue: pasta, rice and bread are a good source of this!!!

simple carbohydrate

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norptei

Clue: responsible for growth and repair.

protein

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What is a ‘Balanced Diet’?

Everyone needs to eat a balanced diet, depending on the physical demands of the sport.

The diet of a rower would be totally different from that of a Sumo wrestler!!!

Diet, work and restFor every physical activity the body requires energy and the amount depends on the duration and type of activity.

Energy is measured in kcal and is obtained from the body stores or the food we eat.

This food provides energy for:

-Growth and repair of the body’s tissues.-Contributes to general good health

CarbohydratesCarbohydrates contain the fuels that provide us with energy to sustain our performance

Glucose in the form of Glycogen is broken down from carbohydrates to provide energy.

Foods containing carbohydrates

Fruit

Breads

Biscuits

Rice

Breakfast cereals

Pasta

Potatoes

Root vegetables

Fats

Fat provides very slowly released energy

– This is important for endurance activities.

The longer you work the more fat is used.

The fitter you are the more easily your body uses up stores of fat

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Fats are also used for energy, but only when stores of carbohydrate run low.

Foods containing fats

Butter

Margarine

Cooking oil

Meat

Sausages

Cakes

Cheese

Cream

Proteins are especially important for sportspeople who need to build up large, powerful muscles.

Performers in sports like weightlifting, rugby and sprinting need high protein diets

Proteins are used to generate energy only when the body has exhausted its stores of carbohydrates and fats.

Proteins

ProteinsHelp us grow and repair muscle

E.g. Some body builders eat a dozen raw eggs everyday!!

Proteins are also needed by performers who are recovering from injury in order to repair damaged tissue.

Proteins are found in…?

Meat and fish

Beans

Nuts and soya

Dairy products and eggs

FibreVery important for maintaining good health

Found in form of plant material that we cannot absorb and is passed through the body.

Fibre is required to aid the smooth working of our digestive system.

Your body needs vitamins to help it function.

Vitamins are needed to:

- resisting infection and disease

- regulate chemical reactions in the body.

Vitamins

How it aids the sports person:

Contributes to the general health of an athlete.

How do we get vitamin D & C? Research and report back to the class

Vitamin C

Vitamin D

Vitamins

This is a lack of vitamin C!!!

Needed in small quantities but are vital for the body

Found in: Calcium in milk,

: Iron in meat

Minerals

How it aids the sports person:

Increased efficiency of carrying oxygen to muscles.

Minerals are needed by the body in small amounts in order to stay healthy.

Calcium

Iron

Minerals

How do we get vitamin D & C? Research and report back to the class

WaterThe human body is 75% water

We need regular intake to replace the water lost through urine, sweating and breathing.

When exercising the body loses even more water – risk of dehydration

Water during exercise

It is essential to keep taking a small amount of fluid at regular intervals during exercises to enable the body to function properly

Symptoms of dehydration: tiredness, lack of concentration and headaches

Performers exercising in hot climates may need to drink up to 2 litres of water per hour!

Body Water Loss Symptoms 1% Few symptoms or signs of any thirst. 2% Beginning to feel thirsty; loss of endurance capacity

and appetite. 3% Dry mouth; performance impaired. 4% Increased effort for exercise, impatience, apathy,

vague discomfort, loss of appetite. 5% Difficulty concentrating, increased pulse and

breathing.6-7% Impairment of temperature regulation, higher pulse and breathing, flushed skin, sleepiness, tingling, stumbling, headache.

8-9% Dizziness, laboured breathing, mental confusion, further weakness.

There are many factors that will effect the energy requirements of people.

-Exercise level - The more exercise someone does the more energy needed.

-Age – Younger individuals need more energy than older adults.

-Gender – Women tend to need less energy intake than men.

Energy Requirements

Basal Metabolic Rate (BMR)

The body needs energy all the time even when we sleep.

The lowest form of energy requirement is call BMR

Each Sport has a different energy requirement depending on:

-Length of game-Intensity of activity-Level of opposition

Table of energy used in different sports:

Activity: Energy used per

hr

Activity: Energy used per

hr

Rugby 1130KJ Walking 380KJ

Squash 1254KJ Golf 560KJ

Jogging 1320KJ Badminton 710KJ

Cycling 1380KJ Tennis 1000KJ

Swimming 1500KJ

Body Weight

There is a clear link between calorie intake, exercise levels and weight.

Every person has an optimum weight. This depends on a number of factors:

-Height

-Gender

-Bone structure

Body Weight

Some athletes need to maintain their weight carefully

(i.e. boxers and jockeys)

The table shows a weight guide based on height

Overweight

A person who is significantly heavier than their optimum weight is classed as overweight.

- “having weight in excess of normal”

Extra weight can be in the form of muscle mass.

People who are underweight are 10% under optimum weight.

Underweight

This can lead to:

-Women have irregular periods

-Can lead to malnutrition

-Poor health

-Energy drain

Weight loss should be gradual and realistic. Dieticians will oversee weight loss and ensure it is safe.

How would body weight affect participation in sport?

TASK: Think with the person next to you

How would body weight affect participation in sport?

-Fatigue quickly

-Speed when playing/speed of movement

-Strength levels

-Flexibility may be affected

-The need for more weight in certain activities i.e. Rugby prop

Somatotypes

Somatotyping is a method of determining an individuals body shape

Body shape is determined genetically (born with it). It can be improved but not dramatically changed

3 Basic Somatotypes

1. ENDOMORPH (Fat) Wide hips and Narrow shoulders Shot putters, sumo wrestlers.

2. MESOMORPH (Muscular)Narrow hips and broad shouldersTennis, rugby, sprinters & swimmers

3. ECTOMORPH (Thin)Narrow hips and shouldersHigh jumper, marathon runner

Somatotype is important, it may mean that you are better suited to one sport more than another.

Somatotypes

Many people are a normal shape – not an extreme body type.

You can be a mixture of body types.

Dietary intake and performance

What an athlete eats in the run up to an event can greatly affect performance.

Redistribution of blood during exercise

Muscles need a continued supply of oxygen, which is provide through the bloodstream. Therefore blood plays a vital role during exercise.

When exercising, the distribution of blood around the body changes according to the demands. Blood flow reduces to systems not in use (i.e. Digestive system)

High protein diet

Athletes that require high levels of protein in the diet include weightlifters and other power events. This is because their training involve increasing muscle mass. Protein will therefore aid recovery between training.

Performers recovering from injury will increase protein intake to aid recovery.

Creatine supplements (a form of protein) will enhance muscle repair.

Carbohydrate loading

This is traditionally associated to long endurance events such as the marathon.

By filling up on carbohydrates performers build up a store of glycogen in the body

This ensures their energy levels are maintained throughout the long, gruelling race.

The night before long endurance events athletes have ‘pasta parties’!!!

This is because carbohydrates energy is released slowly through the body, unlike simple sugars which give a quick burst of energy followed by a slump!!

NO!YES!

Diet and hydration before, during and after exercise

Pre-event: a week before competition athletes should taper their training and will begin to carbohydrate load their body.

Day of event: athletes will usually have a larger meal 3 to 4 hours before the competition. They should make sure fluid levels are HIGH.

Diet and hydration before, during and after exercise

During the event: Any prolonged exercise reduces water levels in the body. Low water levels will result in a decrease in performance. Regular water intake will prevent dehydration.

After the event: An athlete will continue to drink fluids to replace the water and carbohydrate levels that are depleted.

Write 1 sentence to summarise the effects of dehydration on the body.

Write a sentence to describe carbohydrate loading.

Describe why a weightlifter would need a high protein diet.

Classwork Questions