Diet and nutrition

• Healthy balanced diet


  Eating the right nutrients the body needs to be healthy
• Healthy balanced diet composition

  • 55% carbohydrates
  • 15% protein
  • 30% fats
  • Portions of fruit and vegetables per day
  • 2 litres of water
• Nutrient


  A substance that provides nourishment essential for life and growth
• Types of nutrients

  • Macronutrients (carbohydrates, proteins, fats)
  • Micronutrients (vitamins, minerals)
  • Fibre
  • Water
• Carbohydrates

  • Provide the body with a primary source of energy in ATP from glucose and glycogen
  • Needed for the glycolytic and aerobic system
  • Endurance athletes carb load before an event to maximise their fuel stores
• Carbohydrate-rich foods

  • Potatoes
  • Pasta
  • Fruit
• Protein

  • Made of amino acids which build and repair muscles
  • Can be used as an energy source after carbohydrates and fats
  • Strength athletes require more protein than endurance athletes
• Protein-rich foods

  • Milk
  • Eggs
  • Meat
  • Soya
  • Cheese
• Fats

  • Provide the body with a secondary fuel source of energy after carbohydrates
  • Form a protective cushion for organs
  • Unsaturated fats are healthy, saturated fats are unhealthy
  • Broken down into glycerol and fatty free acids which provide energy for low intensity aerobic exercise
• Fat-rich foods

  • Avocado
  • Bacon
• Fibre

  • Made up of indigestible compounds of plants
  • Prevent over eating, CHD and diabetes
• Fibre-rich foods

  • Cereal
  • Bread
• Functions of vitamins and minerals

  • Boost the immune system
  • Support normal growth and development
  • Help cells and organs function healthily
• Vitamin A


  • Aids growth and development
• Vitamin B

  • Helps are red blood cells and convert glycogen to energy
• Vitamin C

  • Forms collagen for healthy bones
• Calcium


  • Builds strong bones
• Iron


  • Helps haemoglobin carry oxygen
• Water

  • Regulates body temperature and heart rate
  • Transports essential nutrients
  • Hydration decreases blood viscosity which increases cardiac output
  • Dehydration decreases performance and impairs concentration
• Water-rich foods

  • Sports drinks
  • Watermelon
• Energy intake

  The total energy/calories consumed in food and drink, measured in joules/calories
• Energy expenditure

  The total energy/calories used daily
• Components of energy expenditure

  • Basal metabolic rate
  • Physical activity
  • Thermic effect
• Basal metabolic rate

  The lowest rate of energy expenditure needed to sustain the body's essential physiological processes at rest after 8 hours of sleep and 12 hours fasting
• Resting metabolic rate

  The lowest rate of energy expenditure needed to sustain the body's essential physiological processes at rest. Weight (kg) / 22
• Energy balance

  The relationship between energy intake and energy expenditure
• Possible energy balance states

  • Positive energy balance (EI>EE, weight gain)
  • Negative energy balance (EE>EI, weight loss)
  • Neutral energy balance (EE=EI, weight maintained)
• Positive energy balance


  Can result in increases muscle mass, increased intensity/duration of exercise, improved recovery and increased fat mass that can result in increased risk of lifestyle diseases
• Negative energy balance

  Can result in weight/muscle loss, decrease intensity/duration of exercise, slow recovery rate and increased risk of fatigue/injury/illness
• Ergogenic aid is a technique or substance used to enhance performance or recovery.
• Nutritional aid is a supplement or drug that enhances performance by increasing the levels of naturally produced hormones, e.g pre/during/post event meals, hydration, carbohydrate/glycogen loading, creatine, caffeine, bicarbonate and nitrate.
• Pharmaceutical aid is a technique that enhances performance by directly influencing the physiological capacity of a particular body system, e.g anaerobic steroids, erythropoietin and human growth hormone.
• Physiological aid is a supplement, food or drink that is consumed to enhance performance or recovery, e.g blood doping, intermittent hypoxic training and cooling aids.
• Pre event meals:

  For events lasting more than an hour, more than 1g/kg body mass of carbohydrates should be consumed, usual range is 1 to 4g/kg.

  1 to 6 hours before an event low glycemic index carbohydrates should be consumed, 1 to 2 hours before an event high glycemic index carbohydrates should be consumed.

  To top up carbohydrate stores, to maintain liver/muscle glycogen stores, to maintain blood glucose levels and to prevent glycogen depletion.
• During event meals


  1. If event is less than 45 minutes, nothing is required

  2. If event is 45 minutes to 75 minutes, small amounts/possibly in fluid form can be consumed

  3. If event is more than 60 minutes, 30 to 60g per hour can be consumed (more important on training days)
• Carbohydrate intake recommendations


  • Medium intensity up to an hour a day = 5 to 7g/kg body mass/day
  • High intensity 1 to 3 hours per day = 6 to 10g/kg body mass/day
• Depends on the event when they will be used
• To sustain carbohydrate availability

  To maintain blood glucose levels and to prevent glucose depletion
• Post event meals:

  Consume 1g/kg body mass/hour of carbohydrates, in solid or liquid form, include protein and other nutrients in meal.

  First 2 hours after an event = body is most susceptible to glycogen synthesis, the optimal time is 30 minutes post event as this is the metabolic window.

  To replenish glycogen stores and including protein produces a higher rate of glycogen synthesis than carbohydrates alone.
• Hydration evaluation:

  Regulate body temperature, regulate heart rate, maintain blood volume and regulate transport of essential nutrients. Increased blood viscosity, decreased blood flow, increased lactic acid production, early OBLA, thermoregulation and increased core body temperature.