4.1 - Diet and nutrition and their effect on physical activity and performance Flashcards
what are simple carbohydrates?
- quickest source of energy
- easily digested by the body
- found in fruits and processed foods
- anything with refined sugar added
what are complex carbohydrates?
- found in nearly all plant-based foods
- usually takes longer for the body to digest
- most commonly found in bread, rice pasta and vegetables
what type of exercise are carbohydrates used for?
- main fuel for high-intensity/ anaerobic work
how are carbohydrates broken down?
- they are digested and converted into glucose
- then enters the bloodstream
- then stored in the muscles and liver as glycogen
what are saturated fats?
- found in sweet and savoury foods
- most come from animal sources
- too much = excessive weight gain
- ultimately: reducing stamina, flexibility and can lead to health problems, e.g, coronary heart disease, atherosclerosis, diabetes and an increase in blood pressure
what is cholesterol?
- type of fat found in blood
- too much saturated fats will lead to an increase in cholesterol
- mainly made in the liver
- carried in the blood as LDL and HDL
what do the LDL and HDL do in the body?
LDL
- too much leads to fatty deposits in arteries
HDL
- takes cholesterol away from the parts of the body where it has been accumulated to the liver where it is disposed of
what are trans-fats?
- artificial hydrogenated fat
- found in meat and dairy products
- most is made from an industrial process –> allowing food to have a longer shelf life
what can trans-fats lead to?
- high levels of blood cholesterol
- heart disease
- diabetes
what are fats used for?
- low-intensity aerobic work (e.g jogging)
- can’t be used for high-intensity as oxygen is in limited supply and it needs oxygen to be broken down
what can fats carry?
- fat-soluble vitamins
- e.g: vitamins A, D, E and K
are all fats bad?
No
- should replace saturated fats and trans-fats with unsaturated fats –> major source of energy in the body
what is atherosclerosis?
where arteries become clogged with fatty substances
what are HDLs and what do they do?
High Density Lipoproteins
- transport excess cholesterol in the blood back to the liver to be broken down
- classed as ‘good’ cholesterol (lowers the risk of developing heart disease)
what are LDLs and what do they do?
Low Density Lipoproteins
- transport cholesterol in the blood to the tissues
- classed as ‘bad’ cholesterol (linked to an increase risk of heart disease)
what are proteins and what do they do?
- combination of mainly amino acids –> major source of energy
- important for muscle growth and repair to make enzymes, hormones and haemoglobin
who tends to consume more proteins?
- power athletes
- have a greater need to repair and develop muscle tissue –> muscular hypertrophy
what do vitamins do?
- keeps an individual healthy with a good immune system
- allows a performer to train maximally and recover quickly
what is vitamin C?
aka Ascorbic acid
- source: green vegetables and fruit
what are the exercise-related functions of vitamin C?
- protects cells -> keeps them healthy
- required for the breakdown of carnitine
- helps in the maintenance of bones, teeth, gums and connective tissue (e.g ligaments)
what is carnitine?
a molecule essential for the transport of fatty acids into the mitochondria
(VC helps mitochondria in converting food sources)
what is vitamin D?
made by our body under the skin when it’s exposed to sunlight
(lesser extent you can get it from oily fish and dairy produce)
what are the exercise-related functions of vitamin D?
- has a role in the absorption of calcium –> keeps bones and teeth calcium
- helps with phosphocreatine recovery in the mitochondria
what is vitamin B1?
Thiamin
- helps break down and release energy from food
- keeps nervous system healthy
what is the source of vitamin B1?
yeast egg liver wholegrain bread nuts red meat cereals
what is vitamin B2?
Riboflavin
- helps break down and release energy from food
- keeps skin, eyes and nervous system healthy
what is the source of vitamin B2?
dairy products liver vegetables eggs cereals fruit
what is vitamin B6?
- helps to form haemoglobin
- helps the body to use and store energy from protein and carbohydrates in food
what is the source of B6?
meat fish eggs bread cereals vegetables
what is vitamin B12?
Folate
- makes red blood cells and keeps the nervous system healthy
- releases energy from food
what is the source of B12?
red meat
dairy products
fish
what is the importance of calcium during exercise?
- needed for strong bones and teeth
- necessary for efficient nerve and muscle contraction
what is the importance of sodium during exercise?
- helps to regulate fluid levels in the body
- too much sodium: increase blood pressure which increases the risk of stroke or heart attack
what is the importance of iron during exercise?
- involved in the formation of haemoglobin in red blood cells (helps transport oxygen and therefore improve stamina)
- lack of iron can lead to anaemia
define a balanced diet
a diet containing a variety of foods from each of the food groups so there is adequate intake of nutrients
define glucose
a simple sugar and the major source of energy for the body’s cells
what is the source of fibre?
wholemeal bread, pasta, potatoes, nuts, seeds, fruit, vegetables, pulses
why is fibre important for exercise?
it can slow down the time it takes the body to break down food
- results in a slower, more sustained release of energy
what does dietary fibre do?
causes bulk in the small intestine
to prevent constipation and aid digestion
define dehydration
occurs when the body is losing more fluid than it is taking in
what does water do for your body?
- transports nutrients, hormones and waste products around the body
- regulates body temperature (keeps you from overheating) –> especially during exercise when energy is released as heat (sweat)
- essential for good health
- makes up 60% of a person’s weight
what does dehydration cause?
- increase in blood viscosity –> reducing blood flow to working muscles and skin
- reducing sweating to prevent water loss (therefore increase in core temperature
- muscle fatigue
- headaches
- reduction in the exchange of waste products/ transport of nutrients
- increased heart rate –> lower cardiac output
- decrease in performance/ reaction time and decision making
what are the 4 dietary supplements?
- glycogen loading
- creatine monohydrate
- sodium bicarbonate
- caffeine
what is glycogen loading?
used to increase glycogen stores over and above that which can normally be stored (supercompensation)
- used by endurance performers
what are the methods of glycogen loading?
- 6 days before competition –> first 3 days = high protein, exercise of high intensity. next 3 days = high carbs, light intensity exercise
(totally depleting glycogen stores can increase it up to 2 times –> supercompensation) - day before –> 3 minutes high intensity exercise (opens carbo window), replenish glycogen in the next 20 minutes
- non-depletion protocol (week before) –> training intensity reduced, 3 days before = high carbs and light intensity exercise
what are the positive effects of glycogen loading?
- increased glycogen storage (in muscles)
- delays fatigue
- increases endurance capacity
what are the negative during carbo-loading?
- water retention (bloating)
- heavy legs
- problems with digestion
- weight increase
what are the negative during depletion?
- irritability
- need to alter training through lack of energy
what is creatine monohydrate?
used to increase the amount of phosphocreatine stored in the muscles (this will allow the energy system to last longer)
- used by athletes in explosive events (e.g sprints)
what does phosphocreatine do?
fuels the ATP system
- when in the muscles it allows the energy systems to last longer
what are the positive effects of creatine monohydrate?
- aims to provide ATP (energy)
- can help improve recovery time
- replenishes phosphocreatine stores
- allows the ATP-PC system to last longer
- improves muscle mass
what are the negative effects of creatine monohydrate?
- side effects include: muscle cramps, diarrhoea, water retention, bloating and vomiting
- hinders aerobic performance
- mixed evidence to show benefits
what is the ATP-PC system?
an energy system that provides quick bursts of energy and is used for high intensity exercise but it can only last for up to 10 seconds
what is lactic acid?
a by product of anaerobic respiration
- as it accumulates, it causes fatigue
what is sodium bicarbonate?
- an antacid
- increases the buffering capacity of the blood (neutralises negative effects of lactic acid/ hydrogen ions)
- drinking it (or ‘soda loading’) will reduce the acidity within muscle cells
- therefore delaying fatigue and allowing the performer to continue exercise at a very high intensity for longer
what are the positive effects of taking sodium bicarbonate?
- reduces acidity in the muscle cells
- delays fatigue
- increases buffering capacity of the blood
what are the negatives effects of taking sodium bicarbonate?
- possible side effects include: vomiting, pain, cramping, diarrhoea and feeling bloated
what are hydrogen ions?
responsible for the acidity of the blood
define buffering
the ability of the blood to compensate for the build up of lactic acid/ hydrogen ions to maintain pH level
what is caffeine?
a naturally occurring stimulant
- increases mental alertness
- reduces fatigue
- improves mobilisation of fatty acids in the body (therefore, sparing muscle glycogen stores)
- used by endurance performers (who rely on aerobic system –> since fats are the preferred fuel for low intensity, long-endurance exercise)
name the sources of caffeine.
coffee tea cola chocolate caffeinated gels certain energy bars
what are the positive effects of taking caffeine?
- stimulant –> increases mental alertness
- reduces effects of fatigue
- delays use of glycogen stores (can be used as an energy source)
- improves reaction time and decision making
- may benefit aerobic performance
what are the negative effects of taking caffeine?
- loss of fine control
- against rules in most sports (when consumed in large quantities)
- side effects: dehydration, insomnia, muscle cramps, stomach cramps, vomiting, irregular heartbeat, diarrhoea
