diet and nutrition and its effects on physical activity

• Balanced diet.


  A diet containing a variety of foods from each of the food groups so there is an adequate intake of nutrients.
• Glucose.


  A simple sugar and the major source of energy for the body's cells.
• Glycogen.


  The stored form of glucose found in the muscles and the liver.
• Glycaemic index.


  This ranks carbohydrates according to their effect on our blood and glucose levels.
• Cholesterol.


  A type of fat found in the blood.
• Low Density Lipoproteins (LPL)


  They transport cholesterol in the blood to the tissues and are classed a 'bad' cholesterol since they are linked to an increased risk of heart disease.
• High Density Lipoproteins (HDL)


  They transport excess cholesterol in the blood back to the liver where it is broken down. They are classed as 'good' cholesterol since they lower the risk of developing heart disease.
• Amino Acids.


  Used in all body cells to build proteins.
• Electrolytes.


  Salts and minerals found in the blood that can conduct electrical impulses in the body.
• Dehydration.


  Occurs when the body is losing more fluid than it is taking in.
• Glycogen loading.


  A form a dietary manipulation to increase glycogen stores over and above that which can normally be stored. It is used be endurance performers.
• Creatine.


  A compound the body can make naturally which supplies energy for muscular contraction; can also be used as a supplement to increase athletic performance.
• ATP-PC system.


  An energy system that provides quick bursts of energy and is used for high intensity exercise but it can only last up to 10 seconds.
• ATP (Adenosine tri-phosphate).


  Energy.
• Sodium Bicarbonate (NaHCO3)


  A white soluble compound used as an antacid. Increases buffering capacity of the blood so it can neutralise effects of lactic acid and hydrogen ions produced in the muscles during high intensity activity.

  It reduces acidity within the muscle cells in order to delay fatigue and allows performer to continue exercising at very high intensity for longer.
• Buffering.


  The ability of the blood to compensate for the build-up of lactic acid or hydrogen ions to maintain the pH level.
• Hydrogen ions.


  Responsible for the acidity of the blood.
• Lactic acid.


  A by-product of anaerobic respiration; as it accumulates it causes fatigue.
• Caffeine.


  A naturally occurring stimulant which can increase mental alertness and reduce fatigue. Improves mobilisation of fatty acids, sparing muscle glycogen stores. Used by endurance performers who rely on the aerobic system, since fats are the preferred fuel for low intensity long endurance exercise. FOund in coffee, tea, cola, chocolate.
• Diuretic.


  Increases the production of urine.
• Describe the importance of carbohydrates and fats for a games player.


  • Both are important energy sources.

  • Fats are important to last the match/used for

  long-duration, low-intensity work.

  • Fats are a good source of vitamins A, D, E and K.

  
  

  • Carbohydrates are the main energy provider.

  • Carbohydrates are the only food source that

  can be broken down anaerobically, which will

  be needed for high-intensity activity during a

  game, for example sprinting.
• Explain the importance of vitamin B6 for an elite performer.


  • Helps form haemoglobin, therefore increasing the oxygen-carrying capacity of the blood

  • Helps the body to use and store energy from

  protein and carbohydrate in food.
• Explain the importance of calcium for a sports performer.


  • Needed for strong bones

  • Needed for muscle contraction/nerve

  transmission (important during exercise)
• Describe on method of glycogen loading and outline the benefits to an elite performer. (5)


  Method A:

  • Reduce glycogen levels by endurance training/exercise.

  • For three days follow low-carbohydrate diet

  • combined with tapering/reduction in training.

  • Next few days follow high-carbohydrate diet

  • combined with little or no training.

  • Increase water intake (aids glycogen storage).

  
  

  Method B:

  • Day before competition complete 3 minutes of high-intensity exercise.

  • 'Carbo window' opens immediately after exercise.

  • Eat high-carbohydrate diet within 20 minutes

  of finishing exercise.

  • 'Carbo window' closes after 2 hours.

  • Increase water intake (aids glycogen storage).

  
  

  Method C:

  • Non-depletion protocol

  • where training intensity is reduced the week

  before competition.

  • Then three days before the competition a

  high-carbohydrate diet is followed

  • with light-intensity exercise.
• What problems will an athlete face if they dehydrate? (4)


  • Increased body temperature/overheating

  • Reduced sweating/reduced blood flow to skin

  • Increased blood viscosity/blood becomes thicker

  • Increased heart rate/cardiovascular drift

  • Lower cardiac output

  • Transportation of oxygen/carbon dioxide less efficient

  • Decreased performance/slower reaction time

  • Headaches/dizziness/cramp
• Explain why an elite performer may choose to take sodium bicarbonate. (4)

  • Sodium bicarbonate is an antacid

  • Increases the buffering capacity of the blood/neutralises the negative effects of lactic acid and hydrogen ions

  • Reduces acidity in the muscle cells

  • Delays fatigue

  • Allows the performer to continue exercise at a very high intensity for longer
• Evaluate the importance of sodium in an athlete's diet. (2)

  • Pros - regulates fluid levels in the body

  
  

  • Against - linked to an increase in blood pressure

  • which can increase the risk of a stroke or heart attack
• Why should a games player have a diet rich in fat?


  Energy source.

  Important to last the match.

  Good source of vitamins A, D, E and K.

  
  

  Can gain weight.

  Limited flexibility.

  Limits stamina.

  Causes health problems such as coronary heart disease/diabetes/high blood pressure.
• Give the exercise-related function of vitamins C and D.


  C:

  Protects cells and keeps them healthy.

  Helps in the maintenance of bones, teeth, gums and connective tissue such as ligaments.

  
  

  D:

  Has a role in the absorption of calcium, which keeps bones and teeth healthy.
• Eating a diet with sufficient calcium and iron would have physiological benefits for an athlete. State the importance of these two minerals for the athlete.


  Iron helps production of red blood cells/haemoglobin which helps transport oxygen and improves stamina.

  Calcium for bones.

  Calcium for muscle contraction/nerve transmission which is important during exercise.
• What are the possible physiological effects of a lack of water on the performer?


  Increased body temperature.

  Reduced sweating.

  Increased blood viscosity.

  Increased HR/CV drift.

  Lower BP.

  Lower cardiac output.

  Transportation of oxygen and carbon dioxide less efficient.

  Possible cramp.

  Headaches/dizziness.
• Which of the following statements about vitamin D is true?

  a) Helps absorb calcium, which keeps bones and teeth healthy.

  b) Helps form haemoglobin.

  c) Makes red blood cells and keeps the nervous system healthy.

  d) Keeps the skin, eyes and nervous system healthy.

  (1)

  a) Helps absorb calcium, which keeps bones and teeth healthy.
• Footballers need stamina to play the game effectively. State two classes of food that are most suitable for players who require stamina and explain why they are needed in their diet. (3)

  Carbs and fats.

  Carbs are the principal source of energy used for both high and low intensity exercise.

  Fats are an energy source for long duration, low intensity exercise.
• Which class of food is most important for a weightlifter? Give reasons for your answer. (2)

  Protien.

  For muscle growth and repair which will be needed after a training session where the performer has worked at high intensity.
• Discuss the potential benefits and harmful effects to an athlete in taking caffeine supplements. (4)

  Increase alertness.

  Improves decision making and reaction time.

  Can benefit aerobic performance.

  Fats can be used as an energy source.

  
  

  Side effects e.g. dehydration, insomnia, muscle cramps, vomiting, irregular heartbeat, diarrhoea.
• Simple carbs

  Quickest source of energy.

  Easily digested by the body.

  Fruits and processed foods.
• Complex carbs

  Take longer for body to digest.

  Found in bread, pasta, vegetables.
• Carbs

  Principal source of energy used by the body.

  Main fuel for high-intensity or anaerobic work.

  Digested and converted into glucose and enters bloodstream.

  Glucose stored in muscles and liver as glycogen but is limited.
• What are the 3 types of fats

  Saturated fats

  Cholesterol

  Trans-fats
• Saturated fats

  Come from sweet and savoury foods but most comes from animal sources

  Too much leads to weight gain, reducing stamina, flexibility and casues health problems e.g. coronary heart disease, atherosclerosis, diabetes and high blood pressure.