food classes

• Carbohydrates


  simple - fruit/processed - easily digestible

  complex - bread, pasta, rice. takes longer to digest

  main energy source, converted to glucose and enters the bloodstream.glucose stored in muscles as glycogen but these stores are limited so regular refuelling is needed

  carbs always being used but as intensity increases, energy from fat decreases and energy from carbs is primary source
• Fats


  saturated fats - mostly from animal sources. too much = excessive weight gain, worse stamina, limited flexibility and coronary heart disease, diabetes and high blood pressure

  trans fats - no more than 5g a day

  unsaturated fats - major energy source of body, used for low intensity

  fats not used for anaerobic work as O2 is required to break down fat
• Proteins


  amino acids - used in cells to build protein. important for muscle growth and repair and to make enzymes, hormones and haemaglobin

  minor source of energy

  used by power athletes that need to repair and develop muscle tissue

  protein will provide when glycogen and fat stores are low
• Vitamins


  fat soluble (A,D,E and K) - in fatty foods and animal products. stored in liver and fatty tissue for later date

  water soluble (B and C) - not stored in body so need to be taken daily
• minerals


  calcium - healthy bones

  iron - forms haemoglobin in red blood cells, lack of iron leads to anaemia

  sodium - keeps fluid levels regulated. too much leads to high blood pressure, increase risk of heart attack
• fibre


  slows down time it takes to break down food ensuring a slower release of energy eg bread and pasta
• water


  60% of body weight

  transports nutrients, hormones and waste products around the body. Regulates body temperature and prevents overheating through sweating
• dehydration


  sweating begins, water loss occurs. dehydration can lead to:

  • increase blood viscosity, blood flow to muscles and skin reduced
  • reduced sweating to stop water loss, increase in temperature
  • muscle fatigue and headache
  • reduction in exchange of waste products
  • incresed hart rate - lower cardiac output
  • decreased performance/reaction time