Quick questions on Recovery strategies for VCE Physical Education Unit 4 AoS 2

Active recovery is light aerobic exercise (typically 30 to 60 per cent of HR max) performed in the minutes to roughly an hour after a hard effort. Examples include light jogging, easy cycling, or pool swimming.

Passive recovery is rest with no exercise. Sitting, lying or standing still.

Hydration replaces fluid lost through sweat. Sweat rates in trained athletes can reach approximately 1 to 2 L per hour in cool conditions and 2 to 3 L per hour in hot conditions. Even a 2 per cent loss of body mass through dehydration measurably impairs aerobic performance; larger losses impair cognitive function and skill execution as well.

Nutrition replaces fuel stores depleted during training. The targets vary by training mode.

Sleep is the primary recovery period for any athlete. Adolescents require approximately 8 to 10 hours per night (Sleep Health Foundation guidance). Most VCE athletes get less than this and most accumulate sleep debt across the school week.

Cold water immersion involves submerging in cold water (commonly approximately 10 to 15 degrees Celsius for 10 to 15 minutes) shortly after exercise. Contrast bathing alternates cold and warm immersion.

Compression garments apply graduated pressure to limbs. They are worn during exercise, in the recovery window post-exercise, or both.

Massage is manipulation of soft tissue, performed by a therapist or self-administered with foam rollers and similar tools.

The light contraction maintains the skeletal-muscle pump, which sustains venous return and elevated cardiac output. Sustained blood flow through muscle delivers oxygen for re-oxidation of lactate and accelerates lactate clearance. Lactate is shuttled to other muscle fibres, the heart and the liver, where it is re-oxidised to pyruvate and either re-enters the Krebs cycle or is converted back to glucose.

Active recovery does not appear to add benefit beyond the first hour or so post-exercise. After that, what is needed is rest, nutrition and sleep.

Muscle glycogen is the primary fuel for moderate to high-intensity exercise. After exercise that depletes glycogen substantially, intake of approximately 1.0 to 1.2 g of carbohydrate per kg body mass per hour for the first 4 hours accelerates glycogen restoration. The "glycogen window" (a period of elevated glycogen synthesis in the 1 to 2 hours post-exercise) is real but smaller in magnitude than is often claimed.

Resistance training, eccentric loading and prolonged exercise produce muscle protein breakdown that must be balanced by protein synthesis. Intake of approximately 0.25 to 0.4 g of protein per kg body mass (typically 20 to 40 g for a 70 to 90 kg athlete) every 3 to 5 hours across the day supports protein synthesis. Sources include lean meat, fish, dairy, eggs, soy and legumes.

A meal containing both carbohydrate and protein in the post-exercise period supports glycogen restoration and protein synthesis. AIS Nutrition guidance recommends a recovery meal within roughly 1 to 2 hours of finishing a hard session.

Cold water immersion produces a small but measurable reduction in perceived muscle soreness and improved short-term recovery of performance after eccentric or high-impact training. The effect on performance recovery is modest. There is consistent evidence that cold water immersion immediately after resistance training can blunt some of the molecular signalling that drives hypertrophic adaptation, so it should not be used immediately after sessions where hypertrophy is the goal.

Explain the mechanism by which active recovery accelerates lactate clearance after a 400 m race. [3 marks]