Quick questions on Pre, during and post-performance nutrition: HSC PDHPE Core 2

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.

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

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:

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

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.

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.

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.

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.

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

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.

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.

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).