Nutrition Flashcards
What are the 7 nutrients?
- protein
- carbohydrates
- fats
- minerals
- vitamins
- fibre
- water
What are the energy providers?
- carbohydrates
- fat and protein
Where is carbohydrate- glucose/glycogen stored?
- in muscle, liver and blood
What is excess carbohydrate converted to?
Triglycerides
What is glycolysis?
The breaking down of glycogen
How many kcal are in 1g of glycogen?
4 kcal
What is fatty acids and glycerol stored as?
Triglycerides or adipose tissue
What is the breaking down of fat?
Beta oxidation
How many kcal are in 1 gram of fats?
- 9 kcal
What can only be used aerobically (medium intensity)?
Fat
How many kcal are in 1g of protein?
- 4 kcal
What does carbohydrate loading involve?
It involves depleting the glycogen stores/ levels seven days prior to the event by doing endurance based training and then starving the body of carbohydrate over the following 3 days
- for the remaining days eat high carbohydrate meals to boost glycogen muscle stores form up to double normal capacity
- increased water intake is also required
Glycogen loading
- up to 1.5-2 hrs
- endurance athletes
- delays fatigue
- aim is to increase glycogen levels
Carbohydrate loading (method)
- reduce glycogen levels for the first few days (1-3) out of 7
- eat low carb diet
- continue to exercise
- then reduce training and eat high carb diet for few days (bodies response is thankful so stores 4.5-4hrs of glyocgen)
- super compensation- body is forced into storing more glycogen
Advantages of carbohydrate loading
- increased glycogen stores
- delays fatigue
- increased time to exhaustion by up to 30%
Disadvantages of carbohydrate loading
- poor recovery in first 3 days
- high irritability in 3 days (not enough fuel to function)
- increased risk of injury
- reduces self confidence and affects mental preparation
How is energy measured?
In kilojoules (KJ) or kilo calories (Kcal)
Obesity
A person is considered obese if they have a body mass index (BMI) of 30 or greater
Calculation of BMI
Body weight (kg)/ height (m^2)
What is priming?
- high intensity for part of the warm-up (sustained) before the race
- improves how quickly your body can process oxygen and deliver more oxygen to muscles
- effect can last for half an hour or more
- boosts oxygen kinetics and increases time to exhaustion
- its where you do a. Hard bursts of exercise above your normal threshold before you do your exercise
- effects of this last half an hour
- if you prime to hard then you will deplete your anaerobic energy stores slowing you down
What are the forms of energy?
- potential
- kinetic
Potential
- (stored energy)
- it has the ability (potential) to do something e.g. batteries and phosphocreatine and ATP
- stored energy within its bond (chemical)
- energy isn’t released until bond is broken
Kinetic
- energy during an objects motion
E.g. throwing a ball, walking
Types of energy
- mechanical
- electrical
- chemical
Chemical energy
- Carbon rates, such as sugar/ starch are broken down into glucose- this is the body’s main form of chemical energy
- it comes from the food we eat and can be transformed into many other forms of energy
Electrical energy
- our cells are specialised to conduct electrical currents
- in our bodes, we have sodium, potassium, calcium and magnesium and these all have a specific electrical charge
- almost all of our cells can use these charged elements (called ions) to generate electricity
Mechanical energy
- the chemical energy we get from the food we eat gets changed into mechanical energy of moving muscles
Basal metabolic rate
- the energy you need to stay alive, awake and warm, while at rest
Working energy
- the extra energy you need to perform all other activities e.g. move, work, exercise
Total energy needed
Basal metabolic rate + working energy
Basal metabolism
- involuntary activities that your body does to stay alive and maintain function
- digestion
- respiration
- circulation
- removing waste products
- regulating body temperature
65-70% of your total energy intake (daily) accounts for this
Water
- 70% of body mass is attributed to water
- without it, death will occur within a matter of days
- almost all bodily functions require a water solution
Water usage
- digestion
- via urine (1.5l) per day
- in faeces (0.11)
- via perspiration (sweating)- 0.85l per day
- expelled air- bi product of respiration (0.35l per day)
Perspiration and expelled air change with exercise
Consequences of dehydration
- increased viscosity of blood
- blood move slow
- increase in heart rate due to reduced blood volume
- increase on body temp
- accompanying electrolyte loss through sweating
What is the leading cause of muscle cramps?
Dehydration
Hyperthermia
- hotter than 37 degrees
Heat exhaustion
- usually experienced when unacclimatised, caused by dehydration owing to excessive sweating
Heat stroke
- complete failure of the heat regulating mechanism brought on by high temperatures
- sweating fails. Means there is a medical emergency
What are the 3 aims of sport drinks?
- hydration
- provide energy
- electrolyte replacement
Isotonic drinks
- 5-7% concentration
- make sure they have the same amount of glucose compared to the blood glucose levels so it can be digested quickly
- gastric emptying is fast
- aids absorption
Hypotonic drinks
- less glucose levels compared to the bloods glucose levels
- less than 4% concentration and quickly replaces bodily fluids
Hypertonic
- higher amount of glucose levels compared to the blood glucose levels
- gastric emptying is slow
- > 20%
- beneficial post exercise for glycogen replenishment
Water content
- coke: low
- lucosade (sport): medium
- water: high
Electrolyte content
- coke: low
- lucosade (sport): medium
- water: low/m
Energy content
- coke: high
- lucosade (sport):medium
- water: low
Speed of digestion
- coke: slow
- lucosade (sport)- fast
- water: fast
Hypertonic/ hypotonic/ isotonic
- coke: hypertonic
- lucosade (sport): isotonic
- water: hypotonic
Why is staying hydrated a challenge of sports performers
- because they sweat when exercise is getting harder to maintain their body temperature
- respiration (bi-product= water)
- climate
Phosphocreatine
- substance found in muscle that supports anaerobic energy provision
What5 does it do? - increase bodies PC stores
- delays lactate production
- supports power/ speed performance
Drawbacks - cramps
- water rentention/ weight gain
Herbal remedies- ginseng
- increases mental alertness
- boost entry levels
- increase VO2 max/ reduce OBLA
Herbal remedies- glucosamine
- joint stiffness/ inflammation
Herbal remedies- arnica
- sooth inflammation, bruising, pain
Herbal remedies- camomile
- reduce stress, support sleep and promote tissue repair
Cherry juice
- helps post-workout recovery
- fights inflammation and arthritis pain
- reduces swelling
- boosts immunity
- regulated metabolism and fights fat
- helps sleep and blocks cancer growth
Bicarbonate soda
- alkali
- neutralises the acidity of lactic acid
- reduces fatigue
Drawbacks
- sickness
- bloating
Caffeine
- stimulant
-stimulates central
nervous system - also a diuretic
- promotes fat metabolism
Drawbacks:
disrupt sleep - nervousness
Staying the same weight
- eating and using the same amount of calories
Losing weight
Eating less and burning more calories
Gaining weight
Eating more and burning less
