DIET AND NUTRITION Flashcards
How many calories should the average male consume a day?
2550 Calories
How many calories should the average female consume a day?
1940 Calories
In what ways can a carefully planned diet affect/improve sports performance? (4 Ways)
- Improve training
- Fitness and performance gains
- Recovery
- Over training risks
What are the 7 components of a healthy diet?
Fibre Vitamins Minerals Carbohydrates Fats Water Protein
What is function and importance of CARBS?
Essential part of a diet for energy production, cell division, transport and formation of molecules.
They are the preferred fuel for exercise, accounting for approximately 75% of energy requirements.
Food sources for CARBS?
STARCH- e.g. rice and potatoes that are stored as glycogen in the liver and muscles.
SUGARS- e.g. fruit and honey which circulates the bloodstream as glucose.
Performance links with CARBS?
Carbs are an essential part of the diet for endurance performers such as marathon runners, who exercise for sustained periods of time.
What is the function and importance of PROTEINS?
Amino acids are essential for growth and repair of cells and tissues.
They make muscle proteins
Proteins can be broken down to provide energy aerobically if no other fuel is available.
Food sources for PROTEINS?
Milk, eggs, meat and soya
Performance links for PROTEINS?
To build new muscle cells and compensate for the increased muscle breakdown during and after intense activity.
Function and importance for FATS?
Insulate nerves Form cell membranes Cushion organs Provide energy stores Broken down for aerobic energy, production and have twice the energy yield of carbohydrates
Food sources for FATS?
Saturated fatty acids = Butter and bacon (Reduce cardiovascular disease)
Unstatuates fatty acids = Avocado and soya beans
Performance links for FATS?
Omega 3 fish oils are beneficial for athletes, boosting the delivery of oxygen, improving endurance and recovery rates and reducing inflammation and stiffness of joints.
Function and importance for MINERALS?
Inorganic nutrients required in small quantities to maintain healthy body functions.
Bone and tooth health controlling body fluids,enzyme formation,breaking down food to release energy and normal nerve function.
Food sources for MINERALS?
Meat Cereals Fish Dairy foods Vegetables Fruits Nuts
Calcium – important for bone health, muscle contraction, blood clotting and nerve transmission.
Iron – important for the formation of haemoglobin, enzyme reactions and the immune system.
Phosphorous – important for bone health and energy production
Performance links for MINERALS?
Nerve function and energy production
Function and importance of VITAMINS?
Maintain healthy body functions
Food sources for VITAMINS?
Fat soluble vitamins are stored in the body and found in fatty foods and animal products (Vegetable oils) For example:
- Vitamin A = Antioxidant and important for eye health, cell and bone growth
- Vitamin D = Important for bone health and protects against cancer and heart disease
- Vitamin E = Antioxidant and important for skin, eye and immune system health
- Vitamin K = Important for blood clotting and bone health
Water soluble vitamins are not stored and require regular intake (fruit, vegetables,grains and dairy foods). For example:
- Vitamin C = Important for skin blood vessels, tendons, ligaments and bone health.
- Vitamin B = Important for breakdown of food, hemoglobin formation and skin, eye, and nervous health.
Performance links for VITAMINS?
Can improve fine and complex motor control and endurance for high altitude athletes.
Function and importance for FIBRE?
Reduce high cholesterol, risk of diabetes and obesity.
Food sources of FIBRE?
Cereal Bread Beans Lentils Fruit Veg
Function and importance of WATER?
Allows chemical reactions, dissolve and move substances around the body.
Regulate temperature by moving heat to skin for evaporation.
Food sources for WATER?
WATER :)
Performance links for WATER?
Good for performance
Regulates temp
Dehydration can result in decreased plasma volume
SV and increase temp and heart rate
Endurance strength will suffer as a result
What is energy?
Energy = ability to perform work and is measured in joules or calories.
1 calorie = 4.18 joules
Not meeting energy requirements can result in what?
Muscle loss (atrophy) Decrease intensity and duration of performance Slower recovery rates Increased risk of fatigue Increased risk of injury and illness
An individual’s daily calorie intake can be affected by?
Age Gender Size Environment Lifestyle Metabolic rate
What is energy expenditure?
Energy expenditure = basal metabolic rate (BMR), the thermic effect of food (TEF) and the energy expended in physical activity.
What is BMR ( Basal metabolic rate)?
BMR = minimum amount of energy required to sustain essential physiological function at rest – can be as much as 75% of total energy expenditure.
What is TEF (Thermal effect of food)?
Thermic effect of food = energy required to eat, digest, absorb and use food taken in.
Uses small % of total energy expenditure.
What is physical energy expenditure?
Physical activity energy expenditure = total number of calories required to perform daily tasks, estimated in MET values.
MET = Metabolic Equivalent value
Working MR:Resting MR
How do you calculate womens BMR?
Women: BMR = 655 + (9.6 X weight in kg) + (1.8 x height in cm) – (4.7 x age in yrs)
How do you calculate a males BMR?
Men: BMR = 66 + (13.7 x weight in kg) + (5.0 x height in cm) – (6.8 x age in yrs)
What is a MET?
Why are they used?
MET – ratio of a performers working metabolic rate and resting metabolic rate
(MET) values are used to build a precise picture of the additional energy expenditure for different sports!
What is 1 MET?
The body uses 1kcal per kg of body mass per hour at rest (1kcal/kg/hr) which is equivalent to an oxygen uptake of 3.5ml/kg/min.
Sitting relaxed, with no activity = 1 MET
What is energy intake?
Energy intake is the total amount of energy from food and beverages consumed and measured in joules or calories.
What is the recommended composition of the average diet?
55% carbohydrate
15% protein
30% fat
What is energy balance?
Energy balance is the relationship between energy intake and energy expenditure.
Energy intake matches energy expenditure?
Energy intake is greater than energy expenditure?
Energy intake is lower than energy expenditure ?
- Weight maintained
- Weight gained
- Weight lost
What can weight gain lead too?
Weight gain can lead to % of body fat rising within the body – causing increased risk of CV diseases and a reduction in performance.
What can weight loss lead too?
Weight loss can be beneficial for individuals following a specific weight loss programme. For athletes, this needs to be monitored to avoid loss of muscle mass and performance.
What is an ‘ergogenic aid’?
It is a substance, object or method used to improve the performance of an athlete.
What are PHARMACOLOGICAL AIDS?
What are the 3 examples?
Pharmacological aids are taken to increase the levels of hormones or neural transmitters naturally produced by the body, most of which are illegal.
ANABOLIC STEROIDS
ERYTHROPOIETIN (EPO)
HUMAN GROWTH HORMONE (HGH)
What are ANABOLIC STEROIDS?
They are a group of synthetic hormones which resemble the male hormone testosterone and are taken to promote protein synthesis and muscle growth. Available in tablet, capsule, solution (injection) and cream form.
Who uses ANABOLIC STEROIDS?
This type of substance is associated with maximal and explosive strength based performers such as sprinters, throwers, baseball and rugby players.
What are benefits of ANABOLIC STEROIDS?
- Increased muscle mass and strength
- Increased speed of recovery
- Increased intensity and duration of training
What are risks of ANABOLIC STEROIDS?
Irritability, aggression and mood swings
Liver damage, heart failure
Acne and hormonal disturbances
What is ERYTHROPOIETIN?
PO is a naturally produced hormone responsible for the production of red blood cells.
A synthetic copy ‘RhEPO’ (Recombinant) can be supplemented to increase red blood cell production.
How is ERYTHROPOIETIN used?
When athletes inject it, the increase red blood cell count increased oxygen capacity/transport and aerobic capacity
Benefits of ERYTHROPOIETIN?
Increased red blood cell and haemoglobin count
Increased oxygen transport and aerobic capacity
Increased intensity and duration of performance before fatigue
Who uses ERYTHROPOIETIN?
EPO is associated with endurance athletes such as marathon runners, triathletes and most notably – Tour de France cyclists!
What are the risks of ERYTHROPOIETIN?
Increase in blood viscosity Decreased cardiac output Increased risk of blood clots Increased risk of heart failure Decrease in the natural production of EPO
What is the HUMAN GROWTH HORMONE ?
HGH is a synthetic product copying the naturally produced growth hormone.
As the natural hormone decreases with age, the synthetic product increases protein synthesis for muscle growth, recovery and repair.
Who uses HUMAN GROWTH HORMONE?
Performers associated with this are maximal and explosive strength athletes such as power lifters, bodybuilders, sprinters, and throwers.
Why is HUMAN GROWTH HORMONE hard to detect?
HGH is also difficult to detect due to naturally occurring levels in the blood – some athletes prefer this method over testosterone as there are fewer side effects!
Performance benefits of HUMAN GROWTH HORMONE?
Increased muscle mass and strength
- Increased fat metabolism and decreased fat mass
- Increase blood glucose levels
- Increased speed of recovery
- Increased intensity and duration of training
Performance risks of HUMAN GROWTH HORMONE?
Abnormal bone and muscle development
Enlargement of the vital organs leading to potential organ failure
Increased risk of cancers and diabetes
What are PHYSIOLOGICAL AIDS?
Examples..
A group of ergogenic aids used to increase the rate of adaptation by the body to increase performance.
Blood doping – ILLEGAL
Intermittent hypoxic training (IHT)
Cooling aids
What is BLOOD DOPING?
Blood doping is an illegal method of increasing red blood cell content.
How does BLOOD DOPING take place?
Step 1: A volume of blood is removed from the body around 4 weeks before competition.
Step 2: The body will naturally replenish the lost blood.
Step 3: Then, a couple of hours before the event, the previously removed blood is reinfused.
Benefits of BLOOD DOPING?
Increased red blood cell and haemoglobin count
- Increased oxygen transport and aerobic capacity
- Increased intensity and duration of performance before fatigue
Risks of BLOOD DOPING?
Increased blood viscosity
Decreased cardiac output
Increased risk of blood clots and heart failure
Risk of infection – hepatitis/HIV
What athletes blood dope?
Endurance athletes
What is Intermittent hypoxic training?
A method where athletes live at sea level, but train under low oxygen pressure environments (hypoxic conditions)
What athletes use Intermittent hypoxic training?
Endurance performers use this method such as marathon runners, triathletes as well as team game players.
How can hypoxic training be performed?
HT can be performed with aerobic and high intensity anaerobic intervals, with athletes wearing a mask supplying low levels of 02.
Benefits of Intermittent hypoxic training?
Acclimatisation for events at altitude
Increased red blood cell, haemoglobin and oxygen carrying capacity
Increased intensity and duration before fatigue
Increased mitochondria and buffering capacity, delaying OBLA.
Risks of Intermittent hypoxic training?
Easily reversible – any benefit of IHT lost when stopped
- May lose motivation and disrupt training patterns
- Hard to reach normal work rates
- Decrease immune function and increase risk of infection
- Dehydration
What is OBLA?
The point where there is a dramatic rise in blood lactate levels causing the onset of fatigue
What are COOLING AIDS?
Cooling aids are a range of products used to reduce core temperature, treat injury and speed up recovery.
Why would you use COOLING AIDS pre event?
Cooling aids such as ice vests and cold towel wraps can be used before an event to reduce core body temperature.
By reducing core body temperature, an athlete can sustain intensity and speed whilst reducing thermal strain and cardiovascular drift.
How can COOLING AIDS be used as injury treatment?
Cooling aids, ice packs and sprays can be used to treat injuries by reducing pain and swelling.
Nerve endings are numbed to reduce pain and arterioles vasoconstrict to reduce blood flow and minimise swelling.
Common with games players, especially in contact sports.
Why would you use COOLING AIDS post event?
Ice baths can be used to speed up recovery by reducing exercise-induced muscle damage and delaying DOMS.
Blood vessels constrict, removing waste and lactic acid from muscle tissue.
Associated with games players and endurance athletes
Benefits of COOLING AIDS?
Reduced core body temperature Decreased sweating, dehydration and early fatigue Decreased injury pain and swelling Increased speed of recovery and repair Decreased DOMS
Risks of COOLING AIDS?
Difficult to perceive exercise intensity Ice burns and pain Hidden injuries Chest pain Dangerous for those with heart conditions (if used on chest area)
Glycaemic index (GI) - What is it?
– A rating scale showing how quickly a carbohydrate affects blood glucose levels.
Hypoglycaemia – what is it?
– low blood glucose levels associated with dizziness, shaking and raised heart rate.
What is GLYCOGEN LOADING?
Also known as CARBOHYDRATE LOADING!
Athletes alter their carbohydrate intake during the week before their event to maximise glycogen stores in the muscles and liver. Associated with endurance performers!
Benefits of GLYCOGEN LOADING?
Increased glycogen stores
Increased endurance capacity
Delays fatigue
Increased time to exhaustion by up to 30%
Risks of GLYCOGEN LOADING?
Hypoglycaemia in the depletion phase Poor recovery rates in depletion phase Lethargy and irritability Gastrointestinal problems Increased risk of injury Affects mental preparation
GLYCOGEN LOADING PROTOCOL –
Day 1: glycogen-depleting bout of endurance exercise
Day 2-3: high protein, high fat
Day 4: glycogen-depleting bout of endurance exercise
Day 5-7: high carbohydrate diet while training is tapered or reduced to resting.
What does DEHYDRATION cause?
Decrease heat regulation and increase in temperature
Increase blood viscosity
Increased heart rate
Increased fatigue
Decreased cognitive function and skill level
Also…Loss of electrolytes (salt and minerals) through sweat can also cause fatigue and cramping.
What can losing 2% of body weight in sweat cause?
Losing 2% of body weight in sweat can cause up to a 20% decrease in performance!
What are hypertonic solutions?
What sort of athletes use them?
Hypotonic solutions:
Contain lower concentration of glucose than the blood stream (4% glucose).
Replaces fluids lost by sweating – providing small amounts of glucose for energy.
Used by athletes for hydration WITHOUT energy boost such as jockeys and gymnasts.
What are isotonic solutions?
What athletes use them?
Contains equal concentration of glucose in the blood stream (5-8% glucose).
Absorbed at same rate as water – quick to rehydrate and provide energy.
Used by middle to long distance athletes and games players.
What are hypertonic solutions?
Hypertonic solutions:
Drinks contain higher concentration of glucose than the blood stream (15%). Absorbed slower than water, consumed POST exercise to maximise glycogen replenishment.
What is Creatine supplementation?
Consumption of creatine monohydrate to increase stores of PC to increase intensity and duration of performance.
How is creatine produced?
Is produced naturally in the body from amino acids and can be consumed by eating meat. Almost all creatine is stored in the muscle tissues as phosphocreatine (PC) and used to fuel very high intensity energy production.
What does creatiene do?
Increases muscles stores of PC by up 50%, allowing a performer to train at a higher intensity for longer.
Benefits of Creatine?
Increased PC stores
Increased fuel for very high intensity energy production (ATP-PC system)
Increased energy and duration of training
Increased maximum and explosive strength
Risks of Creatine?
Increased weight gain Increased water retention Muscle cramps Gastrointestinal problems Long term effects on health and unclear
What is caffeine?
A stimulant used to heighten the central nervous system and mobilise fats to prolong aerobic energy production.
What does consuming 2-6 cups of coffee one hour before performance do?
Consuming 2-6 cups of coffee one hour of performance can increase the aerobic capacity of endurace performers. The increased fats as fuel preserves the glycogen stores for higher intensity bouts of activity, delaying fatigue.
What can high levels of caffeine lead too?
Gastrointestinal problems, insomnia and anxiety, and can act as a diuretic, leading to dehydration.
Benefits of Caffeine?
Increased nervous stimulation Increased focus and concentration Increased mobilisation of fats Preservation of muscle glycogen Increased endurance performance
Risks of caffeine?
Diuretic effect leading to dehydration
Insomnia and anxiety
Gastrointestinal problems
What is Bicarbonate?
An alkaline which acts as a buffers to neutralise the rise in lactic acid associated with intense anaerobic activity. Its use is known as soda loading.
What does Bicarbonate do?
When our bodies demand for oxygen exceeds the available supply of oxygen, our body must work anaerobically. Anaerobic exercise results in the formation of by-products including lactic acid and hydrogen ions. These by-products increase the acidity within the muscles, causing pain and fatigue. Sodium bicarbonate is an alkaline, which can buffer the impact of lactic acid and hydrogen ions, allowing the performer to work for longer at higher intensities without fatigue.
Benefits of Bicarbonate?
Reduces acidity in the muscles, delaying fatigue
Bicarbonate increases the buffering capacity of the blood and neutralises the negative effect of lactic acid and hydrogen ions (maintain blood Ph). Whilst running a 400 m race, our bodies are forced to work anaerobically for an extended period of time, leading to a build-up of lactic acid and hydrogen ions, which could cause fatigue on the final straight.
Increases the time in which an athlete can work at high intensities.
Risks of Bicarbonate?
Some people have reported stomach cramps and diarrhea
Unpleasant taste causing nausea
What are nitrates?
Inorganic compounds which dilate blood vessels, reducing blood pressure and increasing blood flow to the muscles.
What do nitrates do?
They are stored in the body as nitrites and under low oxygen, acidic conditions such as during exercise converted into nitric oxide which plays and important role in vascular and metabolic control.
Benefits of nitrates?
Reduced blood pressure
Increased blood flow
Increased intensity of performance
Delays fatigue
Risks of nitrates?
Headaches, dizziness of light headedness
Long term effects on health unclear
Possible carcinogenic risk
