Position Statement

• Carbohydrate loading would not improve 100-metre sprint performance.

Primary Evidence

• 100-metre races use the ATP-PCr system, which relies on creatine phosphate, not carbohydrates.
• This system provides energy for activities lasting 10-15 seconds without requiring glycogen.
• The race intensity and duration mean carbohydrate stores remain unused.

Secondary Evidence

• Carbohydrate loading benefits endurance events exceeding 90 minutes where glycogen depletion occurs.
• Sprint events do not deplete muscle glycogen stores, making carbohydrate loading irrelevant for performance enhancement.

Reinforcement

• Evidence confirms carbohydrate loading offers no benefit since sprinting operates independently of carbohydrate metabolism.

Sample Answer

Sample Answer

Similarities:

• Both pre and post-training nutrition:
• • Require carbohydrate intake to support energy needs.
  • Need appropriate timing for optimal benefit.
  • Support the demands of explosive anaerobic movements.
  • Contribute to improved performance.
  • Require adequate hydration with electrolytes.

Differences:

• Pre-training requires low glycaemic index carbohydrates for sustained energy while post-training needs protein for muscle repair.
• Pre-training focuses on maximising energy stores whereas post-training emphasises glycogen replenishment and recovery.
• Pre-training timing is several hours before while post-training window is within 1-2 hours.
• Pre-training requires moderate portions to avoid discomfort while post-training can include larger intake for recovery.
• Pre-training hydration ensures optimal starting status while post-training replaces significant fluid losses.

Specific Needs:

• Triathletes engage in prolonged aerobic training requiring sustained energy pre-training and comprehensive recovery post-training due to extended duration.

Sample Answer

Similarities:

• Both carbohydrates and fats
• • Fuel the aerobic energy system during the marathon.
  • Contribute to ATP production for sustained movement.
  • Are broken down through aerobic metabolism requiring oxygen.
  • Work together throughout the event with changing ratios.

Differences:

• Carbohydrates provide immediate energy throughout the marathon while fats release energy more slowly.
• Carbohydrates are the primary fuel at higher intensities whereas fats dominate at lower intensities.
• Carbohydrate stores deplete after extended running while fat stores remain abundant throughout.
• Carbohydrates provide less energy per gram while fats provide more concentrated energy.
• Carbohydrates support varying pace changes while fats cannot meet rapid energy demands.

Key Relationship:

• As marathon pace increases, carbohydrate usage increases while fat usage decreases.
• After prolonged running, fat becomes increasingly important as carbohydrate stores deplete.

Sample Answer

• B vitamins assist converting carbohydrates to usable energy, which enables the aerobic energy system to function efficiently throughout endurance events.
• Because they act as catalysts without containing energy themselves, this leads to continuous ATP production needed for sustained prolonged exercise.
• Daily B vitamins from wholegrains and legumes therefore support efficient carbohydrate metabolism, resulting in maintained energy release as carbohydrates fuel aerobic activities.

Evaluation Statement:

• Micronutrient supplementation is moderately effective compared to whole foods for elite athletes.
• Each approach offers distinct advantages depending on specific circumstances and individual needs.

Criterion 1 – Nutrient Absorption and Use:

• Whole foods strongly meet nutritional needs as vitamins function optimally when consumed naturally with other nutrients.
• B vitamins from wholegrains assist carbohydrate-to-energy conversion, crucial for aerobic energy systems.
• Iron from lean meat provides superior absorption for haemoglobin formation and oxygen transport.
• Food sources deliver micronutrients alongside fibre, antioxidants and other beneficial compounds.
• Supplementation partially fulfils requirements but may have lower absorption rates without these supporting nutrients.

Criterion 2 – Deficiency Correction:

• Supplementation effectively addresses diagnosed deficiencies requiring rapid intervention for performance.
• Female endurance athletes with iron deficiency benefit from targeted supplementation when dietary intake proves insufficient.
• Blood tests identify specific micronutrient gaps needing immediate correction before competition.
• Whole foods cannot correct severe deficiencies quickly enough within competitive training cycles.
• Medical supervision ensures appropriate dosing for deficiency correction.

Criterion 3 – Practical Application:

• Supplementation satisfactorily meets convenience needs during travel, competition and intensive training periods.
• Elite athletes maintain consistent micronutrient intake regardless of food availability or preparation time.
• However, contamination risks with banned substances pose serious concerns for competitive athletes.
• Whole foods require meal planning but eliminate contamination risks while providing complete nutrition.

Final Evaluation:

• Both approaches prove moderately effective when used appropriately for different purposes.
• Whole foods should form the nutritional foundation due to better absorption and comprehensive health benefits.
• Supplementation becomes valuable for addressing diagnosed deficiencies and overcoming practical constraints.
• Elite athletes achieve optimal results combining nutrient-dense foods with professionally-guided targeted supplementation based on individual needs.

Sample Answer

Similarities:

• Both athletes require: 
• • The equivalent carbohydrate intake in the hours before competition.
  • Protein for muscle repair and recovery.
  • Planned nutrition timing to optimise performance.
  • Adequate hydration before competing.

Differences:

• Marathon runners require low glycaemic index carbohydrates for sustained energy while sprinters need high glycaemic index carbohydrates for quick energy.
• Marathon runners need significantly higher daily carbohydrate intake plus loading protocols, whereas sprinters require moderate amounts without loading.
• Marathon runners must consume carbohydrates during events for sustained energy, while sprinters only need pre-event intake.
• Sprinters require more protein for explosive muscle damage repair than marathon runners.
• Marathon runners need continuous hydration with electrolytes throughout events, while sprinters focus on pre-event hydration status.

Sample Answer

Judgment Statement:

• Iron intake is highly important for female endurance athletes due to compound risks from training demands and menstruation.

Oxygen Transport Efficiency:

• Iron forms haemoglobin which transports oxygen to working muscles, essential for aerobic cellular respiration.
• Female endurance athletes with adequate iron maintain optimal oxygen delivery throughout prolonged exercise.
• This demonstrates high importance as oxygen transport directly determines aerobic performance capacity.

Menstruation and Depletion Risks:

• Female athletes face dual iron loss through menstruation and training-induced depletion.
• Low iron levels cause decreased haemoglobin, resulting in fatigue and reduced aerobic efficiency.
• This shows substantial importance as deficiency significantly impairs training and competition performance.

Overall Assessment:

• Iron intake proves highly important for female endurance athletes who face greater deficiency risks than other populations.
• Adequate iron through lean meat or supplementation maintains performance capacity.
• The compound effect of gender-specific and training losses makes iron intake critical for sustaining endurance performance.

Sample Answer

• Carbohydrate loading involves substantially increasing carbohydrate intake over 2-4 days while tapering training. This leads to maximised muscle glycogen stores.
• Because glycogen is the primary fuel for the aerobic energy system, this enables marathon runners to maintain energy throughout events lasting over 90 minutes.
• The increased glycogen storage results in delayed onset of fatigue. This occurs because runners have more fuel available before depletion begins.
• Therefore, carbohydrate loading prevents the performance decline known as “hitting the wall” which happens when glycogen stores become exhausted.

Sample Answer

• Consuming 20g protein within 1-2 hours post-exercise maximises muscle repair and supports muscle gain from resistance training.
• Protein intake immediately after training provides essential amino acids when muscles are most receptive to nutrient uptake for recovery.
• Consuming a small protein meal before bed enhances acute recovery and promotes muscle growth during overnight rest periods.