Transcript Carbohydrates/ Carbohydrad

Carbohydrates/
Carbohydrad
Sports Nutrition
Learning Outcomes
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Describe the role of carbohydrates in the energy
system
Identify the types of carbohydrates
Describe the types of carbohydrates
CHO
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Main role is to provide the body with energy
Carbohydrates make up a group of chemical compounds found in plant
and animal cells. They have the empirical formula CnH2nOn or (CH2O)n.
An empirical formula tells the atomic composition of the compound.
Since this formula is essentially a combination of carbon and water,
these materials are called “hydrates of carbon” or carbohydrates for
short.
Carbohydrates are stored in the muscles and liver as Glycogen and in
the blood as blood glucose
An intake of 5-10g of carbohydrate per kilogram (kg) of body weight
per day is recommended – Work yours out…
1g = 4kcal
The daily amount required depends on type of sport, gender and type
of training
Types of carbohydrates
Simple sugars
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Found in sweet foods
such as fruit, sweets,
jam and confectionary
Complex sugars
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Found in wheat based
foods such as pasta,
bread, potato and rice
Simple Carbohydrates
 Essentially sugars
 Easily digested and absorbed
 Provide a quick energy source
 Formed from single and double
sugar units
 The simplest unit of carbohydrates is the
monosaccharide
 The most common monosaccharide in our diet is
glucose
Monosaccharides
 Glucose is vital for our nervous system
 Glucose is also used
to produce (ATP)
 Glucose is often referred
to as a blood sugar
 Other monosaccharides in our diet include
Fructose, also known as fruit sugar as it is found in
fruits and vegetables, and Galactose found in milk
Disaccharides
 When two monosaccharides are found together
they form a disaccharide, a double sugar
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most common disaccharide in our diet is
sucrose or table sugar
 Other disaccharides include
lactose, found in milk,
and maltose found in beer and cereals
Polysaccharides
 Longer
chains of these simple sugar units are
known as polysaccharides or complex
carbohydrates
 The stored polysaccharides can be broken down
to glucose when needed
 Ultimately all carbohydrate consumed in our diet
will end up as glucose, to provide energy
Complex carbohydrates
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These are the ‘starchy foods’ and are an
important source of energy in most diets
Starches are the way plants store their glucose as
many sugar units linked so they are also called
polysaccharides
Broken down more slowly than sugars
Provide a sustained release of energy over longer
periods
Form the largest percentage of our total CHO
intake
Unrefined sources such as wholemeal bread and
wholegrain rice and pasta are best, as they also
contain more micronutrients and fibre
Check Learning
 What elements are carbohydrates made of?
 What is the role of carbohydrates within the
body?
 How much energy do CHO Yield?
 What are the two types of carbohydrate?
 Name the three types of monosaccharide
 Name the three types of disaccharide
Healthy Diet/Diet Gytbwys?
Recommended Nutrient Intake
Untrained?
Fats %
Carbohydrate %
Protein %
Trained?
Fats %
Carbohydrate %
Protein %
Recommended Nutrient Intake
Recommended Dietary
Guidelines - Untrained
Recommended Dietary
Guidelines - Trained
Proteins
10-35%
Proteins
10%
Fats 1520%
Fats 2530%
Carbohydrates
55-60%
Males – 2500kcal
Females – 2000kcal
Carbohydrates
65-75%
Importance of a Healthy Diet
General Health and
Lifestyle
 Maintain a stable body
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weight
 Reduce the risk of
diseases
 Well being
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Competitive
Performance
Optimal performance
Provide enough nutrients
to fuel high intensity
exercise (anaerobic –
without oxygen)
To ensure body type is
suitable for your sport
(somatotype)
Q. What is meant by
somatotype?
Sports specific nutritional
requirements
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Different sports require different nutritional
requirements
Nutritional requirements for different levels of intensity
Exercise Intensity
Main Fuel Source
% of the Fuel Being Used
Low
Fat
Approximately 80%
Moderate
Carbohydrate and
Fat
50%
50%
High
Carbohydrate
80-100%
Pre Competition
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An athletes diet should be high in carbohydrate to
ensure that glycogen stores remain full with reduced
training before the competition
The pre competition meal should be high in
carbohydrates, low in fat, and low in protein
The meal should also be enjoyable and familiar
For example: Michael Johnson 1992 Olympics – ate out
at a Spanish restaurant prior to competition and
contracted food poisoning costing him a place in the
200m final
Carbohydrate Intake
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Carbohydrate intake should be based on an athletes
body weight
It is recommended that approximately 1 gram of
carbohydrate per kg body weight (1g/kg) be consumed
1 hour prior to exercise
The recommended daily intake of carbohydrates for
athletes is 5 to 10 g/kg depending upon the duration
and intensity of exercise/competition (57-61kg = 285610g/kg)
Work yours out…
Pre Competition foods
Breakfast
cereals
and
porridge
Bread,
rolls and
toast
Fruit
juice,
fruit and
dried
fruit
Pre
competition
foods
Rice,
potatoes
and pasta
Rice cakes,
crackers and
wholemeal
biscuits
During Competition
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Well hydrated before the competition having your
last drink about 15 to 20 minutes before the start
Drink at regular intervals (150 to 300ml), ideally
every 15 minutes or whenever you have a break
during competition. Do not wait until you feel
thirsty as you will already be dehydrated
Consider a carbohydrate drink (Sports Drinks) as
this will also refuel glycogen stores
Post Competition
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Competitive events may leave athletes with
substantially reduced or depleted liver and muscle
glycogen stores
To optimise glycogen replacement, carbohydrates
and insulin are needed
Consumption of foods and beverages containing
carbohydrates provides the source of glucose and
will stimulate the release of insulin from the
pancreas
Post competition
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Timing?
Carbohydrate should be consumed as soon after
competition as possible (30 minute window of optimal
absorption)
Meal size?
Consumption of carbohydrate in smaller, more frequent
meals appears to further aid the rate of replenishing
glycogen
Amount of carbohydrate?
To achieve the highest rate of glycogen replenishment,
1.5g/kg of carbohydrate should be consumed within the first
hour immediately after competition