Nutritional considerations: pre-performance (including carbohydrate loading), during performance, post-performance; supplementation (vitamins/minerals, protein, caffeine, creatine products)

Nutrition is the second most-tested topic in HSC PDHPE Core 2 after the energy systems. The syllabus expects you to know the three timing windows (pre, during, post) and the four supplement categories. Strong responses give specific food, timing, and dosing detail rather than generic "eat carbohydrates" advice.

Pre-performance nutrition

The goal pre-performance is to top up fuel stores (especially muscle glycogen), arrive at the event well-hydrated, and avoid gastrointestinal upset during competition.

3-4 hours before performance

A normal pre-competition meal. Mostly carbohydrates with moderate protein and limited fat (fat slows gastric emptying). Familiar foods only - this is not the time to try new things.

Examples used by Australian athletes:

• Oats with banana and honey.
• Wholegrain toast with peanut butter and a small portion of yoghurt.
• Pasta or rice with a small portion of lean chicken or fish, low-fat sauce.
• A sandwich and a piece of fruit.

Typical guidance is roughly 1-4 g of carbohydrate per kg of body weight in the 1-4 hours before performance, scaling down as the event approaches.

1 hour before performance

A small snack to top up blood glucose and prevent hunger during early performance. Light, low-fibre, low-fat:

• A banana.
• A muesli bar.
• A sports drink.
• A piece of toast with jam.

Carbohydrate loading

For endurance events of 90+ minutes (marathon, long-distance cycling, triathlon, very long open-water swims), carbohydrate loading in the days before the event maximises muscle glycogen stores. The current evidence-based protocol is:

• Days 3-1 before competition. Reduce training volume substantially (taper).
• 48-24 hours before. Increase carbohydrate intake to roughly 7-12 g per kg of body weight per day.
• Day of competition. Standard pre-performance meal as above.

Older "classic" carb-loading involved an initial low-carbohydrate phase followed by a high-carbohydrate phase; this is no longer the recommended approach. The simpler high-carb taper produces comparable glycogen stores with less performance disruption.

Carb-loading does not help for events under 90 minutes. The athlete already has sufficient glycogen for shorter events; eating more does not add useful capacity, just stomach discomfort.

Nutrition during performance

The goal during performance is to maintain blood glucose, replace fluid lost to sweat, and replace some electrolytes (especially sodium for long events in heat).

Events under 60 minutes

Water is usually enough. Carbohydrate intake during the event is not typically performance-limiting for shorter durations.

Events 60-150 minutes

Sports drinks (a carbohydrate-electrolyte solution at around 4-8% carbohydrate concentration) provide fluid and a steady carbohydrate drip. Typical guidance is roughly 30-60 g of carbohydrate per hour, taken in small frequent doses rather than large infrequent ones.

Events over 150 minutes

Higher carbohydrate intake (up to 90 g per hour using multiple transportable carbohydrate sources - glucose plus fructose) to delay glycogen depletion. Solid foods (gels, bananas, sandwiches) and sports drinks combined. Sodium intake matters more: dilutional hyponatraemia (low blood sodium from drinking too much plain water) is a real risk in marathon and ultra events.

Hydration

The principle: drink to thirst plus a bit more for longer events. Pre-weigh and post-weigh in training to calibrate sweat rate. Replacing 100% of fluid lost is generally not necessary or even ideal during the event; modest dehydration (1-2% body mass loss) does not significantly impair performance in cool conditions.

Post-performance nutrition

The goal post-performance is to restore glycogen, repair muscle damage, and rehydrate.

The "recovery window"

The first 30-60 minutes post-exercise is when muscle is most receptive to glycogen restoration. The window is less critical than it was once thought - if the athlete will not train again for 24+ hours, total daily carbohydrate matters more than timing. But for athletes training twice a day or competing in tournaments, hitting the window matters.

The standard guidance:

• Carbohydrate. Roughly 1-1.2 g per kg body weight in the first hour post-exercise. Easy targets: a sports drink plus a banana, a recovery shake, a sandwich, or a normal meal if available.
• Protein. Roughly 20-40 g of high-quality protein within 1-2 hours of exercise to support muscle protein synthesis. Easy targets: a glass of milk, Greek yoghurt, a chicken sandwich, a protein shake.
• Fluid. Replace roughly 150% of fluid lost (because some of what is drunk is excreted as urine). Pre- and post-weigh to calibrate.

The 3-R framework (refuel, repair, rehydrate) is a useful shorthand.

Supplementation

Most athletes do not need supplements if their diet is well-constructed. A small group of supplements have credible evidence of performance benefit. The Australian Institute of Sport (AIS) maintains a four-group classification based on evidence: Group A (evidence-supported), Group B (under research), Group C (no benefit), Group D (banned).

Vitamins and minerals

Athletes can usually meet vitamin and mineral needs from a varied diet. Targeted supplementation is justified in three cases:

• Iron for female endurance athletes, vegetarian and vegan athletes, and athletes in heavy training. Iron deficiency anaemia significantly impairs aerobic performance.
• Vitamin D for athletes who train indoors or live at higher latitudes with limited sun exposure.
• Calcium for adolescent athletes still building peak bone mass and for athletes at risk of low energy availability (especially female endurance athletes).

General multivitamins have minimal evidence of performance benefit for athletes who already eat well.

Protein

Protein supplements (whey, casein, plant-based blends) are convenient ways to hit post-exercise protein targets. They do not contain anything that whole food does not contain; they are practical, not magical.

Daily protein targets for athletes are roughly 1.4-2.0 g per kg body weight depending on training type and goals. Most athletes can hit this through normal meals if they are paying attention.

Caffeine

Caffeine is one of the most evidence-supported ergogenic aids. It reduces perceived effort, improves endurance performance, sharpens reaction time, and supports concentration. Typical effective dose is 3-6 mg per kg body weight, taken 30-60 minutes before performance. For a 70 kg athlete that is 210-420 mg, roughly two strong coffees or a pre-workout product with caffeine.

Caffeine is on the WADA monitoring list but not banned (it was banned in elite Olympic sport until 2004, when WADA removed it). Effects vary by individual; some athletes are caffeine-sensitive and perform worse with it.

Creatine

Creatine monohydrate is the most-researched supplement in sports nutrition. It increases muscle creatine phosphate stores, improving ATP-PC system performance. Benefits are best documented for repeated high-intensity efforts (sprint repeats, weight training, team sport sprint repeats).

Standard protocol is 5 g per day for at least 4 weeks (the "loading phase" of 20 g/day for a week is now considered unnecessary). Creatine causes initial water retention (1-2 kg increase in body mass), which is performance-neutral for most sports but worth knowing for weight-classed sports.

Creatine is safe in normal doses and is not banned at any level of sport.

A practical day-of-competition example

A 70 kg HSC PDHPE student competing in a soccer grand final at 2 pm.

• Breakfast at 8 am. Toast with peanut butter, banana, glass of milk, water. Around 80 g carbohydrate, 20 g protein.
• Light lunch at 11 am. Wholegrain sandwich (chicken, salad), banana, water. Around 70 g carbohydrate, 20 g protein.
• 30 minutes pre-kickoff. Sports drink (small dose), short caffeinated coffee. Around 20 g carbohydrate.
• At half-time. Water, sports drink, half an orange. Around 20 g carbohydrate, 250 mL fluid.
• Post-game. Chocolate milk (or a smoothie with banana, milk, oats, honey). Around 60 g carbohydrate, 20 g protein, 600 mL fluid. Normal dinner within the next 2 hours.

That covers all three timing windows in proportion. The strongest HSC answers walk through a similar specific example rather than listing nutrition principles in the abstract.