Quick questions on Nutrition, hydration, supplementation and sleep for performance: HSC Health and Movement Science Focus Area 2

The dominant fuel for moderate-to-high-intensity exercise; refills muscle glycogen between sessions. Recommendations from groups such as the Australian Institute of Sport (AIS) and the International Olympic Committee position statement scale CHO intake to training load:

Supports recovery, repair and synthesis of new muscle protein. Commonly cited ranges in the strength and endurance literature sit around 1.2-2.0 g/kg/day for endurance athletes and 1.6-2.2 g/kg/day for strength and power athletes. Spreading intake across 4-5 meals of ~0.3 g/kg of high-quality protein each is more effective for muscle protein synthesis than a single large dose.

Provides essential fatty acids, fat-soluble vitamins and the dominant fuel for low-intensity work. Generally the residual macronutrient after CHO and protein targets are met, typically ~20-35 percent of total energy.

Iron (especially in female endurance athletes), calcium and vitamin D (bone health), B vitamins (energy metabolism) are common areas of concern. Deficiency screening with a sports physician is preferable to blanket supplementation.

Aim to start exercise euhydrated. Practical approach: ~5-10 mL/kg in the 2-4 hours pre-exercise; pale-yellow urine as a rough indicator.

Replace ~125-150 percent of body-mass loss (i.e. ~1.25-1.5 L per kg lost) over the hours after exercise, with sodium to retain the fluid. A quick check: weigh before and after; the body-mass change is mostly fluid.

Drinking large volumes of plain water without sodium during long events can cause exercise-associated hyponatraemia. Sodium intake matters in long-duration / hot conditions.

~7-9 hours per night.

Often need toward the upper end and beyond; sleep is when much of the recovery (growth hormone release, muscle protein synthesis, central nervous system recovery, memory consolidation) occurs.

A regular sleep-wake schedule (similar bedtime and wake time most days) supports circadian rhythm and reduces sleep debt across a week.

Adding 1-2 hours per night (or a 20-90 min afternoon nap) can improve reaction time, mood and some performance measures in athletes who are sleep-restricted.

Cool dark room, limit screens and caffeine close to bedtime, consistent routine. Travel, late evening competition and early morning training all challenge sleep and need to be planned for.

Travelling across multiple time zones produces circadian disruption; rough rule of thumb is one day of adjustment per time zone crossed. Pre-travel adjustment of sleep timing, controlled light exposure, strategic caffeine and short naps on arrival are common management strategies.

Most athletes do not need most supplements. Food first; supplements only with evidence, dietitian input and batch-testing for banned-substance risk.

Identify the carbohydrate intake range for an athlete on a moderate training day and explain why intake is matched to training load. [3 marks]