Diet and nutrition 2

• Exercise fuel usage- Carbohydrates are main source of fuel during moderate to high intensity exercise.
• Carbohydrates require 15% less oxygen to be metabolised compared to fats
• It takes up to 20 minutes of low intensity exercise for energy to be released from fats due to their long chain structure and the extra oxygen required to break them down
• During rest and low-intensity, long duration exercise, fats are mainly main source of energy
• When are carbohydrates main source of energy?

  During moderate to high intensity exercise
• When are fats main source of energy?

  During rest and low intensity, long duration exercise
• As intensity increases, more carbohydrates are used as fat usage decreases
• Fats can never provide more than 50-60% of total fuel
• During high intensity anaerobic exercise, (e.g long jump) phosphocreatine is the main fuel source
• When is phosphocreatine (PCr) the main fuel source?

  during high intensity anaerobic exercise
• what is phosphocreatine derived from?

  amino acids
• How quickly does phosphocreatine run out?

  after 10-12 seconds
• Phosphocreatine is a naturally occurring compound derived from amino acids that produces energy extremely quickly, but runs out after 10-12 seconds
• The higher the individual's levels of aerobic fitness (VO2 max) the longer the fats will be metabolised- saving important carbohydrate stored for high intensity bursts of exercise
• Aerobic fitness can be improved through continuous, long interval and fartlek training
• How can aerobic fitness be improved?

  • Continuous training
  • long interval
  • fartlek training
• The higher the individuals level of anaerobic fitness, the greater the PCr and glycogen stores, which allow individual to exercise at a high intensity for a longer period of time
• Anaerobic fitness can be improved through plyometrics, HIIT and weight training
• What can improve anaerobic training?

  • plyometric training
  • HIIT
  • weight training
• Training at anaerobic threshold will increase what?

  glycogen stores- allow athlete to exercise at higher intensity for longer
• What is anaerobic threshold?

  The intensity just before lactic acid production gets to critical levels
• Training at anaerobic threshold- the intensity just before lactic acid production gets to critical levels, will increase glycogen stores and allow the athlete to exercise at a higher intensity for longer
• Glycogen loading is manipulation of an athlete's diet, allowing them to delay fatigue and avoid ' hitting the wall'
• What is glycogen loading

  Manipulation of athletes diet to delay fatigue and avoid 'hitting the wall'
• Glycogen loading: Depletion stage (1)

  Reducing muscle glycogen stores- starts 6 days prior
• When does the depletion stage start in carbohydrate (glycogen) loading?

  6 days prior to race day
• Glycogen loading: Tapering stage (2)

  Reducing the intensity and volume of training
• Glycogen loading: Loading stage (3)

  Increasing consumption of carbohydrates- starts 3 days prior
• When does the loading stage start in glycogen (carbohydrate) loading?

  3 days prior to race day
• How does carbohydrate loading enhance performance?

  • delays fatigue
  • enables athlete to work at high intensity for longer
• carbohydrate loading boosts glycogen stores in the muscles/liver thus enhancing performance for endurance athletes by delaying fatigue and enabling the athlete to work at a higher intensity for longer
• elite athletes need to refuel the body as soon as possible in order to re-synthesise muscle and liver glycogen stores and aid growth and repair of muscles
• Why do elite athletes need to refuel the body as soon as possible?

  • to re-synthesise muscle and liver glycogen stores
  • aid growth and repair of muscles
• A meal or shake containing a mixture of GI foods should be eaten within 30 minutes of finishing competition/exercise to start the recovery process
• When should a meal with a mixture of GI foods be eaten after finishing a competition or exercise?

  within 30 minutes