Diet and nutrition and their effect on physical activity and performance — AQA A-Level Physical Education

Diet and nutrition directly affect physical activity and performance by supplying the energy (ATP) needed for muscle contraction and by supporting recovery, hydration and body composition. AQA A-Level PE requires students to understand macronutrients (carbohydrates, fats, protein), micronutrients (vitamins and minerals), hydration, the glycaemic index, and how to manipulate diet for optimal performance in different sports.

This topic explores how diet and nutrition influence physical activity and sports performance. It covers the macronutrients (carbohydrates, fats, proteins), micronutrients (vitamins, minerals, water), and the role of each in energy production, recovery, hydration, and body composition. Students learn to apply nutritional principles to different sporting contexts, including pre-, during, and post-exercise nutrition, and to evaluate ergogenic aids such as creatine and caffeine.

Understanding diet and nutrition is essential for optimising performance, delaying fatigue, and preventing injury or illness. It links closely with energy systems, recovery strategies, and sports psychology (motivation and adherence). In AQA A-Level PE, this topic is examined through multiple-choice, short-answer, and extended-writing questions, often requiring students to analyse data or apply knowledge to a specific athlete's scenario.

• →Carbohydrates are the primary fuel for high-intensity exercise, stored as glycogen in muscles and liver; fats are the main fuel for low-intensity, long-duration exercise; protein is essential for muscle repair and growth but contributes minimally to energy production.
• →The glycaemic index (GI) ranks carbohydrates by their effect on blood glucose; low-GI foods provide sustained energy, high-GI foods provide rapid energy and aid recovery.
• →Hydration is critical for maintaining blood volume, regulating body temperature, and preventing dehydration, which can impair performance; electrolyte balance (sodium, potassium) is also important.
• →Micronutrients (vitamins and minerals) do not provide energy but are essential for energy metabolism, oxygen transport, bone health, and immune function; deficiencies can impair performance.
• →Nutritional strategies must be tailored to the sport, intensity, duration, and individual athlete, including carbohydrate loading, protein timing, and fluid replacement.

• 💡Always link the nutrient to its specific function and the energy system or recovery process it supports. For example, 'carbohydrates are broken down into glucose, which is used in glycolysis to resynthesise ATP'.
• 💡Use specific figures and timing where possible, such as '1.2-1.7 g/kg protein for strength athletes' or '500ml fluid 2 hours before exercise'. This demonstrates precise knowledge.
• 💡When evaluating ergogenic aids, consider both benefits and risks, and cite evidence or studies where appropriate. For example, 'creatine supplementation increases phosphocreatine stores, enhancing ATP-PC system performance, but may cause water retention and gastrointestinal distress'.

• Misconception: 'Protein is the main energy source for exercise.' Correction: Carbohydrates are the primary fuel for high-intensity exercise; fats fuel low-intensity exercise; protein is mainly for repair and growth.
• Misconception: 'All fats are bad and should be avoided.' Correction: Unsaturated fats are essential for health, hormone production, and provide energy for low-intensity exercise; only excessive saturated/trans fats are harmful.
• Misconception: 'You should drink as much water as possible during exercise.' Correction: Overhydration can cause hyponatraemia (low blood sodium), which is dangerous; fluid intake should match sweat loss, typically 150-250ml every 15-20 minutes.

1. 1Day 1-2: Learn the definitions and functions of macronutrients (carbohydrates, fats, proteins) and micronutrients (vitamins, minerals, water). Create a table summarising each nutrient's role, food sources, and recommended intake for athletes.
2. 2Day 3-4: Study the glycaemic index and its application to pre-, during, and post-exercise nutrition. Practice applying GI to different sporting scenarios (e.g., a footballer's pre-match meal vs. a marathon runner's during-race nutrition).
3. 3Day 5-6: Investigate hydration strategies, including fluid and electrolyte balance, and the effects of dehydration on performance. Calculate sweat rates and fluid replacement needs for a given athlete.
4. 4Day 7-8: Explore ergogenic aids (creatine, caffeine, bicarbonate, beta-alanine) and their mechanisms, benefits, and risks. Evaluate the evidence for each and consider ethical issues.
5. 5Day 9-10: Complete practice exam questions, including data analysis and 6-mark extended responses. Use mark schemes to identify gaps and refine exam technique.

• 📋Multiple-choice questions testing knowledge of nutrient functions, energy systems, or hydration guidelines. Advice: read all options carefully and eliminate obviously incorrect answers.
• 📋Short-answer questions (2-4 marks) requiring definitions, explanations, or calculations (e.g., carbohydrate requirement, sweat rate). Advice: show your working for calculations and use correct units.
• 📋Data analysis questions where you interpret a graph or table (e.g., blood glucose levels after consuming high vs. low GI foods) and explain the implications for performance. Advice: quote data from the graph and link it to physiological processes.
• 📋Extended-writing questions (6-9 marks) asking you to evaluate nutritional strategies or ergogenic aids for a specific athlete. Advice: structure your answer with an introduction, balanced arguments, and a conclusion, using specialist terminology.