diet and nutrition Flashcards
a balanced diet is essential for what
optimum performance
it also plays a role in disease prevention
what are the 7 nutrients
carbohydrates
fats
proteins
vitamins
minerals
fibre
water
what is the exercise related function of carbohydrates (used most)
theyre the principle source of energy used consistently for aerobic and anaerobic exercise.
make up 60-65% of balanced diet
glycogen is needed to breakdown other energy fuels (fats)
glycogen is the only fuel source that can be broken down anaerobically
a rich energy source digested and stored in our muscles and liver as glycogen
what is the exercise related function of fats (richest source)
used for low intensity aerobic work only.
and long duration
richest energy food source in the body but can only be used in aerobic resp as it requires o2 to break it down (beta oxidation)
fats still need glycogen to function so cannot be used on its own
20-25% of balanced diet
stored as trigycerides in adipose tissue
fat carries vitamins A, E, D, K, they are stored and used when needed
what is the exercise related function of proteins (4 main things)
a very poor fuel for energy is only used when they are close to fatigue/hitting the wall and other stores are depleted
and making enzymes, hormones and haemoglobin
can increase strength of cartilage and antibodies
15% of balanced diet
ms:
minor source of energy.
used when body has exhausted glycogen and fat stores.
used for growth and repair of muscles.
high intake for eg weightlifting, rugby and sprinting, injury recovery to repair damaged tissue
explain how and why the diet of a competition weightlifter may need to differ from that of an untrained individual (4 hows and 4 whys)
extra calories/carbs/fats because they are used for energy/respiration/atp synthesis.
extra protein so it can be used for muscle growth and repair and development.
extra vitamins and minerals for higher metabolism/muscle nerve functioning/tissue growth/energy release from foods.
extra water to avoid dehydration and replace losses through sweating and for temp regulation
what % yield do we get from carbs and from fats
75% carbs
25% fats if aerobic
what are vitamins
essential nutrients needed in small amounts in order to keep the performer heathy with a good immune system
staying health = train maximally
what are the vitamins we need to know about
c (ascorbic acid)
d
b1(thiamine)
b2 (riboflavin)
b6
b12 (folate)
sources of vitamin c (ascorbic acid)
green veg, fruit
sources of vitamin d
oily fish and dairy
most is from sunlight, made under the skin when exposed to it.
sources of vitamin b1/thiamine
yeast, egg, liver, wholegrain, bread, nuts, red meat, cereals
sources of vitamin b2/riboflavin
dairy products, egg, liver, vegetables, fruit, cereals
sources of vitamin b6
meat, fish, eggs, vegetables, bread, cereals
sources of vitamin b12/folate
red meat, dairy products, fish
exercise related function of vitamin c/ascorbic acid
protects cells and keeps them healthy.
helps maintain skin, bones, teeth, connective tissue and nervous system health.
production of collagen/skin/cartilage/bone.
involved in normal structure and function of blood vessels/nerve fibres
exercise related function of vitamin d
has a role in/controls calcium absorption, keeps bones and teeth healthy.
also needed for phosphorus absorption.
needed for normal bone mineralisation/formation and structure.
exercise related function of vitamin b1/thiamine
works with other b vitamins to release energy from food
keeps nervous system healthy
exercise related function of vitamin b2/riboflavin
works with other b vitamins to release energy from food
keeps skin, eyes and nervous system healthy
exercise related function of vitamin b6
helps haemoglobin
helps the body use and store energy from protein and carb in food
exercise related function of vitamin b12/folate
releases energy from food
makes red blood cells/function
keeps the nervous system healthy
ms:
needed for cell
division/growth
blood formation and function
normal structure and function of nerves.
what are minerals
inorganic chemicals required for bodily functions such as bone and teeth growth, energy metabolism and nerve functions
tend to be dissolved in the body and exist as ions and are called electrolytes
what are electrolytes
salts and minerals found in the blood that can conduct electrical impulses in the body enabling quick and effective muscular contractions
an elite athlete will have a higher metabolism than the average person because
of their significant training load and muscle mass
there is also an increased demand for more fuel to fulfil their training demands
what is glycogen sparing
when a trained athlete uses mostly fats to save glycogen to offset fatigue
as the intensity of the exercise increases the use of glycogen increases
research suggests that athletes should consume 4-6 smaller meals a day rather than 2-3 larger ones, why (2)
it ensures glycogen stores are continuously topped up throughout the day.
allows athletes to train without full stomach which could otherwise cause cramp
before long duration of exercise a ……………. meal should be eaten to boost …..
high carbohydrate meal to boost glycogen levels
when is the carbohydrate window and what does it allow
a carbohydrate meal should be consumed to refuel glycogen stores.
means can train again sooner and so get better
what is a balanced diet
a balanced diet is one that is likely to include a large number or variety of foods so adequate intakes of all nutrients are achieved
it contains all the sufficient nutrients the body requires to be healthy and function efficiently
sufficient/enough/correct amount of each component
the amount of nutrients each person needs depends on our ….
gender, level of maturation, age, level of physical activity and overall BMI
what is glucose
a simple sugar and major source of energy for the bodys cells
what is glycogen
the stored form of glucose found in the muscles and liver
what is glycaemic index
this ranks carbohydrates according to their effect on our blood glucose levels
what are simple carbohydrates
these are found in fruits and processed foods and are easily digested by the body (glucose/sugars)
quickly digested and fast release
what are complex carbohydrates
these are found in plant based foods and take longer to digest and are considered slow release
eg bread, pasta, rice
what are foods with a low glycaemic index and when should they be eaten
they should be eaten by endurance athletes because they release glucose slowly and sustained throughout a long period
eaten 3-4 hours before exercise
fruit, veg, beans, brown rice
textbook- - beans on toast, pasta or rice with vegetable sauce
what are foods with a high glycaemic index and when should they be eaten
cause a rapid and short rise in blood glucose
they should be consumed 1-2 hours before exercise
eg bread, potatoes (banana is medium)
textbook- fruit smoothies, fruitflavoured yog, fruit
what does too much sat fat lead to
weight gain which can decrease flexibility, stamina, and lead to CHD, type 2 diabetes, high cholesterol and hypertension
what is cholestrol
a type of fat that travels in the blood
what is ldl cholesterol
low density lipoprotein
transports cholesterol in the blood to the tissues, considered BAD increasing the risk of heart disease
what is hdl cholesterol
high density lipoprotein that transports excess cholesterol in the blood back to the liver where it is broken down
is GOOD cholesterol reducing the risk of heart disease
what are unsaturated/trans fats inc eg of where its found
they are liquid at room temp, mostly made from hydrogenating fats
found in some nuts
trans fats are found in meat and dairy products.
what are the advantages and disadvantages of a netballer having a diet rich in fat (4)
+:
energy source
aerobic/low intensity/slow release
source of vitamins AEDK
-:
excess mass/obesity
bad for stamina and endurance
limits range of movement and flexibility
performer too warm and overheat
atherosclerosis and atheroma, chd, diabetes, hypertension, cancer
describe the exercise related function of carbs fats and fibre (4)
carbs for fast release energy, used in all intensities, aerobic and anaerobic, slow and quick release
fat for slow release, used at rest and low intensity, aerobic and slow release
fibre slows energy breakdown and allows for sustained energy release
discuss whether a tennis player should have a diet rich in fat (5)
yes: energy source/slow release of energy, important to last the duration of the match/long time.
transport and store and give a source of A, E, D, K vitamins
no: gain weight/excess body fat, risk of obesity
limit stamina, cvd fitness, fatigue more quickly.
reduce flexibility, movement, speed and agility.
overheat
coronary heart diseases/diabetes/highbp/atherosclerosis
briefly explain how 2 different named classes of food in an athletes diet will aid their performance (2)
sufficient:
carbs for energy
fats for energy
protein for muscle growth/repair development.
minerals for bone formation/muscle function/increased metabolsim, electrolyte balance/blood formation
vitamins for increased metabolsim, blood formation
water for medium for reaction/lubricant/regulate temperature/avoid dehydration
what are the minerals we really need to know
calcium
sodium
iron
what is the exercise related function of calcium
necessary for strong bones and teeth, efficient nerve and muscular function (contraction).
main mineral in bones and teeth
what is the exercise related function of sodium
helps regulate fluid levels in the body, important after sport as water is lost through sweat.
too much sodium can increase bp increasing risk of stroke/heart attack ordisease
regulates water content and electrolyte balance.
involved in energy use and nerve function.
what is the exercise related function of iron
required for formation of haemoglobin/rbcs which has the capacity to increase stamina.
iron also supports the immune system.
lack of > amaemia.
needed for normal energy metabolism
needed for removing drugs and foreign substances from the body
what is the exercise related function of magnesium
required for energy metabolism
maintains electrolyte balance
muscle function
what is the exercise related function of phosphorus
like calcium
bone and teeth structure
structure of cell membranes
what is the exercise related function of potassium
is found in bodily fluids and is essential for water and electrolyte balance
what is the exercise related function of iodine
is used to help our metabolism
what physiological benefits are gained by making sure a performers diet contains sufficient iron and calcium (3)
iron: component of haemoglobin/rbc, transport of oxygen, improved stamina/endurance
calcium: component of bones, important for muscle contraction/nerve transmission, increased strength
what is the exercise related function of fibre
can help reduce blood cholesterol levels and help people with diabetes control their bgl and reduce obesity.
fibre acts as a bulking agent and prevents constipation
helps the large intestine digest food
fibre slows the time it takes to digest food allowing more energy to be produced increasing stamina
sources of fibre
bread (wholegrains) and cereal
what is fibre
it comprises the edible parts of plants that arent broken down and absorbed by the small intestine
functions of water
lubrication of eyes and joints.
regulate body temp (evap of sweat cools us).
required for many chemical reactions.
essential in the transportation and removal of nutrients, hormones and waste (plasma carries co2).
blood plasma is 90% water and allows blood to remain at the perfect viscosity, as if it was too viscous > clot>ha/stroke etc
lack of lowers bp, causes heat stroke, denatures enzymes when too hot.
reduces cardiovascular drift, stroke volume and ejection fraction.
dehydration of as little as …. will impact performance
2%
the olympic heptathlon is a 2 day event, throwing, jumping, running.
to maximise P flexibility must be developed and water and electrolyte balance needs to be maintained.
outline the physiological changes that will occur if the correct water and electrolyte balance is not maintained (8)
blood thickens/increases in viscosity.
incr in hr/has to work harder.
reduction in blood flow/less o2 to muscles.
and to skin/incr in body temp/unable to maintain correct body temp/>heat stroke.
slows reaction time/decision making/decrease conc/slows nerve impulses.
muscle fatigue/cramp
irregular heart beat (rhythm as well as beat)
disruption to removal of waste products eg lactic acid/faster to OBLA
common symptoms of dehydration
headache
muscular fatigue
blurred vision
less o2 to working muscles
blood more viscous reduces flow to skin and muscles.
increased heart rate > lower cardiac output.
decreased decision making
increased reaction time
disruption to removal of waste products eg lactic acid/faster to OBLA
reduce sweating > incr body temp
reduction in exchange of waste and transport of nutrients.
what are supplements
the are products used to enhance health and wellbeing and boost sports performance
what is creatine supplementation, what does it do, how is it taken
taking creatine increases the phosphocreatine stores in muscles which helps rebuild the atp through the atp-pc energy system providing longer high intensity exercise preventing the use of lactic acid/aerobic systems so preventing the negative effects of lactic acid
taken as powder in drinks or as a tablet
what are positives of creatine supplementation (5)
provides atp
replenished PCr stores quickly
increases the capacity of the atp-pc system
helps to improve muscle mass and strength
its legal
what are negatives of creatine supplementation
muscle cramps, diarrhoea, water retention, bloating, vomiting
can hinder aerobic performance
if daily intake is over 5g then excess is excreted
what is sodium bicarbonate
an alkaline powder that has a buffering ability allowing it to neutralise lactic acid in the blood preventing its negative effects.
increases buffering capacity of the blood.
reduces acidity in the muscles and prevents fatigue
allows the performer to continue at a higher intensity for longer
positives of sodium bicarbonate
reduces acidity in the muscles
delays fatigue
increases buffering capacity in the blood
negatives of sodium bicarbonate
significant gastric disruption
bloating
pain
cramps
diarrhoea
what is caffeine
a stimulant that increases mental alertness and contributes to reducing fatigue
it mobilises fatty acids promoting their use as a fuel
used by aerobic performers
positives of caffeine
increases mental alertness
reduces effect of fatigue
assists glycogen sparing
increases stamina
increases decision making
reduces reaction time
legal in a small amount
what are negatives of caffeine
loss of fine motor control
dehydration
insomnia
irregular hr
muscle and stomach cramps
vomiting and diarrhoea
against the rules of most sports in large quantities
needs a lot to work
what are the stages of glycogen loading and why is it done
deplete glycogen stores by intensively training (high int) and eating only a fat and protein rich diet for 3 days
and then for the 3 days leading up to the event have a diet high in carb and low int exercise
by depleting and rebuilding up to twice as more glycogen can be stored (prevents “hitting the wall”)
explain how a diet containing sufficient vitamins and minerals contributes to effective performance (2)
vk/folic acid/vitb12/Fe - helps production of rbcs/Hb
Ca/P/vd - for bones
Ca/Mg for muscle contraction
vb2/P/Na/Fe - energy metabolism
K/Na/Ca - nerve transmission
describe 2 benefits of athletes including fat in their diet (2)
used as an energy source
contains fat soluble vitamins/essential fatty acids
acts as an insulator
slow release/low intensity
sodium bicarbonate can be taken as a dietary supplement by a 400m runner
describe how sodium bicarbonate works to delay fatigue (2)
increases the buffering capacity of the blood
reduces acidity/neutralises the effect of lactic acid/hydrogen ions
delays the onset of blood lactate accumulation/obla
evaluate whether a marathon runner should use glycogen loading to enhance performance (4) the positives …
positive effects:
incr storage of musc gly, prevent hitting the wall, as they maintain higher levels of gly for energy production for longer/during later stages of the race (1)
incr aerobic/endurance capacity means they can maintain a consistent pace/mom for longer during the race (1)
delays the effects of fatigue for longer during performance, meaning they maintain a better position/finish the race stronger (1)
evaluate whether a marathon runner should use glycogen loading to enhance performance (4) the negatives ….
negative effects:
depletion phase can cause heavy legs/feeling lethargy which can have a negative impact on training and race preparation
retain more fluids causing a bloated feeling and discomfort when running which may affect their stride pattern/race plan/pacing/concentration
weight gain caused by water retention may slow the runner down during the race/cause them to need to work harder
