Diet and Nutrition

• Balanced Diet 


  Essential for optimum performance in sporting activities
• Simple Carbohydrates 


  Found in fruits and are easily digested by the body.
• Complex Carbohydrates 


  Found in nearly all plant-based foods, and usually take longer for the body to digest.
• Carbohydrates 


  The principle store of energy used by the body. Carbohydrates in food is digested and converted into glucose and enters the bloodstream. Glucose is stored as glycogen in the muscles and liver.
• Saturated Fats 


  Found in both sweet and savoury foods. Too much leads to excessive weight gain, which will affect levels of stamina, limit flexibility and lead to health problems.
• Low-density lipoprotein 


  Too much can lead to fatty deposits developing in the arteries and can have a negative effect on blood flow.
• High-density lipoprotein


  Takes cholesterol away from the parts of the body where it has accumulated to the liver, where it is disposed of.
• Unsaturated Fats 


  Found in meat and dairy products but most are made from an industrial process that adds hydrogen to liquid vegetable oils, which causes the oil to become solid at room temperature.
• Proteins 


  A combination of chemicals called amino acids and are important for muscle growth and repair and to make enzymes, hormones and haemoglobin. They are a minor source of energy and tend to be used more by power athletes.
• Carbohydrates 


  Principle source of energy for both low intensity (aerobic) and high intensity (anaerobic) exercise.
• Fats 


  Used for long duration, low intensity exercise.
• Proteins 


  Minor source of energy and tend to be used more by power athletes.
• Fat-soluble vitamins - A, D, E and K 


  These vitamins are found in fatty foods and animal products such as milk, dairy foods, vegetable oils, eggs, liver and oily fish. The body stores fat-soluble vitamins in the liver and fatty tissues for use at a later date.
• Water-soluble vitamins - the B vitamins and vitamin C 


  They are found in a wide range of foods such as fruits, vegetable and dairy products. They are not stored in the body so they need to be taken daily. Excessive consumption will not have any beneficial effects as any additional amount will be excreted.
• Vitamin C

  • Protects cells and keeps them healthy
  • Helps in the maintenance of bones, teeth, gums and connective tissues such as ligaments
• Vitamin D

  • Has a role in the absorption of calcium, which keeps bones and teeth healthy
• Vitamin B1

  • Works with other B group vitamins to help break down and release energy from food
  • Keeps the nervous system healthy
• Vitamin B2

  • Works with other B group vitamins to help break down and release energy from food
  • Keeps the skin, eyes and nervous system healthy
• Vitamin B6

  • Helps form haemoglobin
  • Helps the body to use and store energy from proteins and carbohydrates in food
• Vitamin B12

  • Makes red blood cells and keeps the nervous system healthy
  • Releases energy from food
• Minerals 


  Assist in bodily functions. They tend to be dissolved by the body by ions and are called electrolytes.
• Functions of minerals 


  Facilitate the transmission of the nerve impulses and enable effective muscle contraction.
• Calcium 


  Needed for strong bones and teeth and is also necessary for efficient nerve and muscle function.
• Sodium 


  Helps regulate fluid levels in the body. Too much sodium is linked to an increase in blood pressure, which can increase the risk of stroke or heart attack.
• Iron 


  Helps in the formation of haemoglobin in red blood cells which helps transport oxygen. A lack of iron can leas to anaemia.
• Fibre 


  Slows down the time it takes for the body to break down food, which results in a slower, more sustained release of energy.
• Water 


  Transports nutrients, hormones and waste products around the body. It is the main component of many cells and plays an important part in regulating body temperature.
• Dehydration

  • Blood viscosity increases, reducing blood flow to working muscles
  • Reduced sweating to prevent water loss, which results in an increase in core temperature
  • Muscle fatigue and headache
  • Reduction in the exchange of waste products and transport of nutrients
  • Increased heart rate resulting in lower cardiac output
  • Decreased performance/Decreased reaction time/Decreased decision making
• Glycogen Loading 


  A form of dietary manipulation to increase glycogen stored over and above that which can normally be stored.
• Six Day Method 


  Six days before an important competition, a performer eats a diet high in protein for three days and exercises at a relatively high intensity to burn off any existing carbohydrate stores. This is followed by three days of a diet high in carbohydrates and some light training.
• Positive Effects of Glycogen Loading

  • Increased glycogen stores
  • Increased glycogen stores in the muscle
  • Delays fatigue
  • Increases endurance capacity
• Negative Effects of Glycogen Loading

  During the carbo-loading phase:

  • Water retention, which can result in bloating
  • Heavy legs
  • Affects digestion
  • Weight increases
• Negative Effects of Glycogen Loading

  During the depletion phase:

  • Irritability
  • Can alter the training programme through a lack of energy
• Creatine 


  A compound the body can make naturally, which supplies energy for muscular contraction. It can also be used as a supplement to increase athletic performance.
• Phosphocreatine 


  Used to furl the ATP-PC system, which provides energy.
• Positive Effects of Creatine Supplementation

  • Aims to provide ATP
  • Replenishes phosphocreatine stores
  • Allows the ATP-PC system to last longer
  • Improves muscle mass
  • Improve recovery times
• Negative Effects of Creatine Supplementation

  • Possible side-effects: muscle cramps, diarrhoea, water retention, bloating and vomiting
  • Hinders aerobic performance
• Sodium Bicarbonate 


  An antacid that can increase the buffering capacity of the blood so it can neutralise the negative effects of lactic acid and hydrogen ions that are produced in the muscles during high-intensity activity.
• 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