Diet and Nutrition Flashcards
7 nutrients in the body
carbohydrates
fats
protein
fibre
water
vitamins
minerals
function of carbohydrates
main source of energy for high intensity exercise within the body
how is carbohydrates broken down
aerobic glycolysis
anaerobic glycolysis
where is carbohydrates stored as glycogen
liver
muscles
how does CHO aid recovery
replenishes glycogen stores used during exercise
food examples of carbohydrates
simple carbs - glucose, sugar
complex carbs - pasta, bread, rice
range of amount of carbohydrates in diet
60-75%
function of fats
major source of energy at rest and low intensity
insulates and protects
range of amount of fats in diet
20-25%
how is fat broken down
betaoxidation
what is needed for fat to be broken down
oxygen
CHO
how is fat important in relation to fat soluble vitamins
transports essential vitamins A,D,E and K around body
3 types of fat consumed through food
unsaturated
saturated
trans
unsaturated fats
liquid and vegetable sources
oily fish, vegetable oils
monounsaturated and polyunsaturated fats
healthier option of fat intake
saturated fats
solid and animal sources
butter, cakes, biscuits
associated with high cholesterol, high risk of heart disease
trans fats
saturated, commercially produced fat to preserve shelf life
found in fast food, biscuits, pasties
possess no nutritional value
high risk of coronary heart disease
chocolate
function of protein
growth and repair of tissue
aid creation of hormones, connective tissue
minor source of energy - extreme circumstances
range of proteins in diet
10-15%
what are proteins converted to and how is this used
amino acids
used to repair and promote muscular hypertrophy
food sources for proteins
animal products - milk, fish, meat
plant foods - beans, lentils
protein supplements - whey, casein
vitamins function in body
functioning of muscles and nerves
growth of body tissue
release of energy from food
food sources of vitamins
fruit and vegetables
function of minerals
required for body functions - bone growth, energy metabolism and nerve functioning
food sources of vitamins
vegetables
meats
function of water
regulate body temperature
prevent dehydration
lubricant for joints
fibre
indigestible parts of plants, pass relatively unchanged through stomach and intestines
function of fibre
aids digestion
helps lower blood cholesterol levels
food examples of fibre
cereals
wholegrain bread
oats
glycaemic index
0-100 rating of how quickly CHO releases energy
3 categories in glycaemic index
low
medium
high
high GI foods
rapidly digested, release energy quickly
sharp increase in blood sugar so insulin spike
what is the range on the glycaemic index for high GI foods?
70-100
what dangers to health do high GI foods pose?
CHO stored as fat in adipose tissue if not used for energy
danger of type 2 diabetes with prolonged consumption due to insulin spoke to control blood sugar leading to becoming insulin tolerant
medium GI foods
trigger moderate increase in blood sugar
range of medium GI foods on glycaemic index
55-69
examples of high GI foods
white rice - 90
cheerios - 74
white bread - 70
examples of medium GI foods
wholemeal bread - 69
baked potatoes - 56
low GI foods
slow digestion, gradual release of energy
gradual rise in blood sugar and insulin levels, no insulin spike
benefits to health of low GI foods
improved glucose levels in diabetics
weight control as control appetite and delay hunger
what is pre-competition meal made up of and when is it consumed?
low GI foods
3-4 hours before competition
examples of low GI foods
banana - 55
baked beans - 48
spaghetti - 41
how is low GI carbohydrate used pre exercise in sport
best strategy for endurance athletes to consume low GI CHO in pre exercise meal to allow sustained slow release energy
3-4 hours before to allow full digestion
e.g. brown bread, fruit, vegetables
how is high GI carbohydrates used during exercise?
release energy immediately - vital to performer for sustained performance to maintain glucose and muscle glycogen levels
consumed through isotonic drinks, gels, jaffa cakes, jelly babies during exercise
why should you avoid high GI CHO immediately prior to exercise
insulin spike can reduce availability of energy for exercise
what category of GI foods are used post exercise?
medium GI
high GI
how should food be consumed post exercise?
consume both high and low GI CHO within 20 minutes post exercise to enhance recovery
allows fast glycogen uptake in muscles from high GI and sustained release from low GI
protein should be included to build and repair muscle
hydration very important
specific recovery drinks with H,M and L GI CHO and proteins consumed immediately after ending
Diet manipulation to maximise energy stores - before exercise
Pre competition meal - high CHO meal - mix of medium and low GI food
Hydration
Diet and manipulation to maximise energy stores - during exercise
Medium to high GI foods/drinks
Maltodextrin - high GI - CHO powder
Use of energy/isotonic drinks
Prevent glycogen depleting too quickly
Hydration
Diet and manipulation to maximise energy stores - after exercise
Eat within 20 minutes stopping exercise
Hydration
Mix of high, medium, low GI CHO
Take on protein - aid growth and repair of muscles
Use of specific recovery drinks
Protein shakes - build + repair, CHO drinks to replete glycogen levels
What are the 3 variables that providing energy to re synthesise ATP is based upon?
Intensity of activity
Duration of activity
Aerobic/anaerobic fitness level of performer
Approximate food level usage for low intensity exercise
Aerobic - lots of oxygen
Fat more than carbs
Fat not utilised without oxygen
Example of how low intensity relates to team sports
Jogging out after break in play
Example of how low intensity relates to MSFT
Level 1
Approximate food fuel usage for medium intensity exercise
Fats and carbs equal
Less oxygen than at low intensity
Reduction in fat usage
Example of how medium intensity relates to team sports
Dummy run
Example of how high intensity relates to MSFT
Level 5
Example of how high intensity relates to MSFT
Level 18
Example of how high intensity relates to team sports
Fast break
Breaking past defender
Approximate food level usage for high intensity
Fat can’t be used for energy
Very little oxygen
Carbs - don’t need oxygen to be broken down and used for energy Very little
Average male kilojoules/calorific intake
2500 calories
10500 kJ
Average female kilojoules/calorific intake
2000 calories
8,400 kJ
Factors why energy requirements differ with different people
Genetic predisposition
Build, gender, age
Metabolism
Environment
Amount of regular physical activity
Athlete’s diet v untrained athlete - CHO/fat, protein, vitamins & minerals, water
CHO/fat - endurance athletes need more CHO + fat for energy demands of training
Protein - Athletes require more protein - extra needed for muscle growth and repair especially by power athlete
Vitamins & minerals - athlete requires more - extra needed for higher metabolism, muscle nerve functioning, tissue growth, energy release from foods
Water - athletes require more - extra needed to avoid dehydration, replace losses through sweating, temperature regulation
Aerobic v anaerobic athlete diet - both athletes
Balanced diet essential for optimal performance - 10-15% protein, 20-25% fats, 60-75% carbohydrates
High CHO diet improves performance - aerobic and anaerobic glycolysis
Fat intake - restricted for both groups, muscle mass = more powerful than fat
Elite power and endurance based athletes supplement diet with nutritional ergogenic aids - whey and casein
Aerobic v anaerobic athletes - endurance athletes
Higher proportions of CHO - 6-10g CHO per kg of body mass
Protein - 1.2-1.4g per kg of body mass
Hydration - water consumption greater
Due to training load, higher metabolism, require inc vitamins and minerals. Need inc fruit, vegetables, dairy products and cereals
Aerobic v anaerobic athlete - power/strength athletes
More CHO because of energy demands - 4-6g CHO per kg body mass
Protein - 1.4-1.8g per kg of body mass, higher protein intake as after heavy resistance training rate of protein breakdown and re synthesis is higher for power athlete
Signs of dehydration
Thirst
Once reach point - hard to rehydrate
What is a more accurate test of hydration levels?
Monitoring colour of athlete’s urine
Hydration
Maintaining correct levels of water in body thus allowing normal bodily functioning
How does dehydration affect performance
Dramatic negative effect
Dehydration
Increase in blood viscosity as fluid is lost from plasma
What does an increased blood viscosity cause?
Decreased blood velocity around the body
Blood viscosity
Thickness of blood
Ways that dehydration/increased blood viscosity impairs physical performance
Decreased stroke volume and increased heart rate
Decrease supply of energy/glucose to muscles
Impaired removal of lactic acid
Muscle function impairment
Decreased heat loss from skin (temp control)
How to maintain levels of hydration prior to exercise
4-7 litres should be consumed over 24 hours
Important fully hydrated before training
Consume 1.5-2 litres of water steadily prior to endurance event over 2-3 hours and not all at once to prevent bloating and possible sickness
How to maintain levels of hydration during exercise
Depends on climate conditions and size of individual
Consume small amounts at regular intervals
Consume 150-250ml every 10-15 minutes/half to 1 litre per hour of exercise
Exercising - 90 minutes + - energy drink can be beneficial to replace lost glycogen stores + electrolytes essential for energy
How to maintain levels of hydration after exercise
Essential to rehydrate to aid recovery
Method - weigh athlete before and after prolonged exercise/competition. Every 1kg of body weight lost, approx. 1 litre of water consumed over period of hours
Hypotonic drink
Thirst quencher
<4g of sugar, little energy
Taken up quicker than water
Recreational sports, shorter/less strenuous exertion
Isotonic drinks
Thirst quencher
Energy provider
4-8g of sugar per 100ml
Endurance sports
Hypertonic drinks
Huge energy provider
Thirst quencher - secondary
>8g of sugar per 100ml
30-60 mins before training + immediately after training
Useful for athletes who need more energy during training
