Lesson 16 · Judging the product
Supplements, micronutrients and ergogenic products
Four legal products, all marketed to athletes, all bought by people your age. Ranking them by how well they work is the easy half of the question. The half that carries the marks is what would have to be true about the athlete for any of them to help at all.
Four products sit on a shelf in a supermarket: a protein powder, a caffeine tablet, a creatine powder, and a multivitamin. All four are legal, all four are marketed to athletes, and all four are bought by people your age.
Rank them from most to least likely to improve a 17-year-old team-sport athlete's performance, and write the reason for your top choice and your bottom one. Then answer the question that matters more: for the one you ranked first, what would have to be true about the athlete for it to help?
- Apply the food-first principle, and say when a supplement is genuinely the right tool.
- Explain the role of micronutrients, and the key distinction between correcting a deficiency and supplementing an athlete who has none.
- Discuss protein supplements: what they do, what they do not do, and when a powder beats food.
- Explain the mechanisms and the limits of caffeine and creatine, the two with the strongest evidence.
- Weigh risks — contamination, regulation, cost and opportunity cost — against claimed benefits, which is what discuss requires.
- Supplement — a product taken in addition to the normal diet, intended to supply a nutrient or to produce an effect.
- Ergogenic aid — anything used with the intention of improving performance.
- Micronutrient — a vitamin or mineral required in small amounts, supplying no energy but essential to function.
- Deficiency — an intake or store low enough to impair normal function.
- Food-first principle — the position that nutritional needs should be met from food unless there is a specific reason they cannot be.
- Creatine phosphate — the compound that rapidly regenerates ATP during very short maximal efforts.
- Loading phase — a short period of higher intake used to saturate a store, most commonly with creatine.
- Placebo effect — an improvement produced by the expectation of benefit rather than by the substance.
- Contamination — the presence in a product of a substance not declared on its label.
- Inadvertent doping — returning a positive test from a substance the athlete did not know they had taken.
- Batch testing — independent analysis of a specific production batch for prohibited substances.
The starting position in sports nutrition is food first: meet requirements from food unless there is a specific reason you cannot. This is not conservatism. Food supplies nutrients together in forms the body handles well, it carries no contamination risk, it costs less, and — most importantly — it does not distract from the things that actually determine performance.
That last point is the one to carry, and it has a name worth using: opportunity cost. An athlete who is sleeping six hours, skipping breakfast and training inconsistently will gain far more from Lessons 6, 7 and 15 than from any product on a shelf. Spending attention and money on a supplement while those remain unaddressed is not neutral; it substitutes an easy action for a hard one.
Three situations genuinely override food first.
| Situation | Example | Why food alone is insufficient |
|---|---|---|
| A diagnosed deficiency | Low iron in an adolescent athlete, identified by a blood test and medical assessment | Correcting an established deficiency through diet alone can be slow or inadequate, and the deficiency is genuinely impairing performance and health |
| A practical constraint | A recovery drink between two matches on the same day, when appetite is suppressed and no food is available | The requirement is real and the opportunity to meet it with food is absent, which is a logistical problem rather than a nutritional one |
| A specific ergogenic effect | Caffeine or creatine, used for an effect that is not available in useful amounts from ordinary food | The dose that produces the effect is not practically reachable through diet, so this is the one genuinely pharmacological case |
Notice what is absent from that table: "because other athletes take it", "because the packaging says it aids recovery", and "as insurance in case my diet is not good enough". The last of those deserves particular scepticism, because insurance against an unknown gap is exactly the claim a product cannot be held to.
Ask what problem the supplement solves, and whether the athlete has that problem. Most supplement use fails at the second question rather than the first.
Quick check: Which is the strongest justification for using a supplement rather than food?
Micronutrients are vitamins and minerals. They supply no energy, but without adequate amounts the systems that do supply energy cannot work. Three matter most in this context.
| Nutrient | Role | Who is at risk | Effect of supplementing someone who is not deficient |
|---|---|---|---|
| Iron | A component of haemoglobin and myoglobin, so central to oxygen transport and use | Adolescent female athletes especially, plus endurance athletes and those with restricted or vegetarian diets | No performance benefit, and excess iron is harmful, so supplementation should follow testing rather than assumption |
| Calcium | Bone structure, and nerve and muscle function | Athletes with low energy availability or restricted dairy intake | No performance benefit in a replete athlete |
| Vitamin D | Calcium absorption and bone health, with roles in muscle function | Athletes training indoors or with very limited sun exposure | No performance benefit in a replete athlete |
Read the last column down and one principle emerges, and it is the most examinable idea in this dot point: correcting a deficiency improves performance; adding more to an athlete who is not deficient does not. The dose-response is not a straight line. It rises steeply out of deficiency and then flattens, and for some nutrients it eventually turns harmful. That single sentence answers most multivitamin questions.
Protein follows the same logic in a different form. Protein supplies the material for the repair and hypertrophy of Lesson 8, so adequate protein is necessary for adaptation. But the stimulus is the training. Beyond an adequate intake, more protein does not produce more muscle; it is used for energy or stored. Most athletes eating enough total food already reach an adequate intake, which is why a protein powder is usually a matter of convenience — a portable, quickly consumed source when whole food is impractical — rather than a source of extra benefit.
The claim to be careful with
"Protein builds muscle" is true only with training and only up to adequacy. An answer stating that a higher protein intake produces greater muscle gain, independently of the training stimulus and above an adequate intake, is describing something the evidence does not support and is repeating marketing.
True or false: Correcting an iron deficiency can improve endurance performance, while giving iron to an athlete who is not deficient produces no performance benefit and can be harmful.
The syllabus names caffeine and creatine specifically, and it is worth knowing why: of the products marketed to athletes, these two have the strongest and most consistent evidence behind them. That does not make them right for every athlete, and both have real limits.
| Caffeine | Creatine | |
|---|---|---|
| Mechanism | Acts on the central nervous system, reducing perceived effort and improving alertness, concentration and reaction time. The effect is largely in how hard the work feels rather than in the muscle itself | Increases the muscle's store of creatine phosphate, the compound that rapidly regenerates ATP during very short maximal efforts, so more work can be done before that system is exhausted and it recovers faster between efforts |
| Where it helps | Broadly: endurance, repeated sprints, and sports requiring sustained concentration. One of the few aids with evidence across very different event types | Repeated short maximal efforts, and resistance training, where it supports greater training volume and therefore greater adaptation over time |
| Where it does not | It cannot replace sleep, and using it to mask fatigue creates the problem in Lesson 15 rather than solving it | Prolonged endurance events, where the limiter is glycogen rather than the phosphate system, and where added mass is a disadvantage |
| Practical use | Taken before the event, with the dose and timing trialled in training. Individual responses differ considerably | Taken daily, with or without a short loading phase, since the effect depends on saturating the store rather than on a single dose |
| Limits and side effects | Anxiety, tremor, gastrointestinal upset, raised heart rate, and disturbed sleep if taken late — which then damages recovery. Adolescents are generally advised to limit intake | Weight gain, largely from water drawn into muscle, which is a disadvantage in weight-category and endurance sports. Requires adequate hydration |
| Non-responders | Some athletes get little benefit and considerable side effect | Athletes whose stores are already high, often those with high dietary meat intake, respond much less |
Two points give an answer real precision. First, caffeine's main effect is on perception, not on the muscle. Work still costs what it costs; it simply feels easier, which is why it improves pacing and concentration and why it is not a substitute for the recovery that would have made the work genuinely easier. Second, creatine works by supporting more training, not by replacing it. The gains attributed to creatine over months are largely the gains from the extra quality work it made possible — which means an athlete not training hard has nothing for it to amplify.
And both carry a consideration specific to school-age athletes. Advice for adolescents is more cautious than for adults, long-term data in young people is thinner, and the same effort spent on sleep, fuelling and consistent training will produce a larger effect in almost every case.
Fill the gaps. Creatine works by increasing the muscle's store of creatine , which rapidly regenerates ATP in very short maximal efforts. Caffeine's main effect is to reduce , acting on the central nervous system. An improvement produced by the expectation of benefit rather than by the substance is called the effect.
The word discuss requires the other side of the ledger, and for supplements the risks are substantial and mostly invisible at the point of purchase.
| Risk | What it means | What reduces it |
|---|---|---|
| Contamination | A product may contain a substance not declared on its label, through cross-contamination in manufacturing or deliberate addition. This is the route to inadvertent doping, and in anti-doping the athlete is responsible for what is in their body regardless of intent | Using only products from independent batch-testing programs, and treating any product with a proprietary or incomplete ingredient list as unusable |
| Regulation | Australian sports supplements may be foods under the Food Standards Code or therapeutic goods under TGA rules; ingredients, form and claims affect classification. Food health claims need substantiation. Some oral products that claim to improve sports performance are declared therapeutic goods if they contain restricted ingredients (such as ingredients scheduled in the Poisons Standard or on the WADA Prohibited List) or are in tablet, capsule or pill form, except glucose-only products; they must be entered in the ARTG before supply. Requirements differ by class and risk, and no regulatory category guarantees a batch is free from contamination | Check the product's classification and ingredients, question performance claims, and use independently batch-tested products to reduce—but not eliminate—contamination risk |
| Side effects and interactions | Real effects with real costs: caffeine disturbing sleep, creatine adding mass, iron excess causing harm, and interactions with medication | Medical or dietetic advice before use, particularly for anyone under 18 or taking medication |
| Cost and opportunity cost | Money spent, and — more damaging — attention diverted from sleep, fuelling and consistent training, which have far larger effects | Fixing the basics first, and asking what the same effort would achieve if spent elsewhere |
Regulation sources: TGA sport-supplement guidance; FSANZ sports foods guidance and health-claims requirements. Classification for a particular product depends on its ingredients, form and claims.
The first row connects directly to Lesson 22. Under anti-doping rules the athlete is responsible for what is found in their sample, and "it was in my supplement and not on the label" is not a defence that removes that responsibility. A product that gives a small benefit and carries a real chance of a sanction is a poor trade, and saying so is exactly the weighing this dot point asks for.
One more consideration belongs in a discussion. The placebo effect is real and measurable, so an athlete may genuinely perform better because they believe a product works. That is not nothing — but it means an athlete's own testimonial is weak evidence about the substance, which is why controlled comparison exists and why "it worked for me" cannot settle the question.
Odd one out. Three of these are legitimate reasons to choose a supplement over food. Which one is not?
This dot point names five things — supplements generally, micronutrients, protein, caffeine and creatine — and asks you to discuss their use for improved performance. A discussion has a shape, and it is the same one every time: for each product, state the claim, the mechanism, the evidence, the limits and risks, and then a judgement about who it is actually for.
| Product | Evidence for a performance effect | Who it is genuinely for |
|---|---|---|
| Caffeine | Strong and consistent across event types, with the effect on perceived effort well established | Athletes who have trialled it in training, do not suffer significant side effects, and are not using it to cover inadequate sleep |
| Creatine | Strong for repeated short maximal efforts and for supporting resistance-training volume | Athletes in power and repeated-sprint sports already training hard, where added mass is not a penalty |
| Micronutrients | Clear benefit when correcting a diagnosed deficiency; no performance benefit otherwise | Athletes with a deficiency identified by testing and managed medically |
| Protein supplements | Adequate protein is necessary for adaptation; extra protein above adequacy adds nothing | Athletes who cannot practically reach an adequate intake from food, for whom the value is convenience |
| Most other marketed supplements | Weak, absent, or drawn from small studies of laboratory markers rather than performance | Very few athletes, and rarely school-age ones |
That table also answers card 01. Ranked by likely benefit to a 17-year-old team-sport athlete, caffeine and creatine sit above protein powder and a multivitamin — but the ranking is almost beside the point, because for every one of them the honest answer is it depends on the athlete. The multivitamin ranks last not because vitamins do not matter but because a replete athlete gains nothing from more of them. And the condition attached to the top-ranked product is the real content of the question: caffeine helps an athlete who has trialled it, tolerates it, and is not using it to paper over a recovery problem that Lesson 15 would fix properly.
Claim, mechanism, evidence, risk, judgement. Five steps, one product at a time. An answer that names products and their claimed effects has done the first step only.
Two truths and a lie. One of these statements is false. Find it.
Activities · judge the product, not the packaging
For each athlete, decide whether you would support the supplement, and give the claim, the mechanism, the risk and your judgement. A defensible "no" is worth as much as a defensible "yes".
A 16-year-old distance runner, frequently tired, whose blood test shows low iron stores.
A 17-year-old rugby player who sleeps six hours a night and wants to start taking caffeine tablets before training.
A 19-year-old sprinter in a structured resistance program, eating well, considering creatine.
A 15-year-old who eats a varied diet and wants a daily multivitamin "as insurance".
Match each term to its meaning.
- Ergogenic aid
- Inadvertent doping
- Batch testing
- Placebo effect
- Anything used with the intention of improving performance
- Returning a positive test from a substance the athlete did not know they had taken
- Independent analysis of a specific production batch for prohibited substances
- An improvement produced by the expectation of benefit rather than by the substance
A product page for a recovery powder makes the following claims.
| # | Claim on the page |
|---|---|
| 1 | "Clinically proven to accelerate recovery." |
| 2 | "In a study, users showed a 23 per cent improvement in a recovery marker." |
| 3 | "Contains a proprietary performance blend." |
| 4 | "Used by professional athletes." |
| 5 | "Extra protein for maximum muscle growth." |
Evaluate each claim. What exactly is being asserted, what would you need to know to judge it, and what is the specific weakness? Then answer three further questions. Which claim is the most dangerous for an athlete subject to drug testing, and why? Which is the most misleading rather than merely unsupported? And if a teammate reports that it works for them, explain precisely what that testimonial can and cannot establish.
Lock it in. In one sentence, explain why correcting an iron deficiency improves performance while giving iron to a replete athlete does not.
Discuss the use of supplements, protein, caffeine and creatine products for improved performance.
Discuss requires arguments on both sides and an informed position. Supplements are a topic where students often argue only one side; the marks require both.
Plan: define the issue, argue the case for use, argue the case against, name the tension, then take a position.
A supplement is a product taken in addition to the normal diet with the intention of improving performance or recovery. The issue is whether the measured benefit justifies the cost and risk, and whether the answer is the same for every product grouped under the term.
For a small number of products the evidence is genuinely good. Creatine reliably increases intramuscular creatine phosphate stores, improving repeated high-intensity efforts and supporting gains in lean mass, and its safety profile in healthy adults is well established. Caffeine reduces perceived exertion and improves endurance and alertness across a range of activities at modest doses. Protein supplements do not outperform food, but they deliver a known quantity conveniently at a time when appetite is suppressed after training, which supports adherence to a target intake. And where a genuine deficiency exists — iron in female endurance athletes, vitamin D in indoor athletes — correcting it produces a real performance improvement.
Evidence and regulation vary across the market. Some sports supplements are foods under the Food Standards Code, where health claims must meet substantiation requirements; others are therapeutic goods under TGA rules. Listed medicines require sponsor-held evidence for their permitted indications, but the TGA does not individually assess each listed medicine's efficacy before listing; assessed listed and registered medicines receive pre-market assessment of efficacy. These rules do not make every product risk-free or guarantee that a particular batch is free from contamination. An advertised claim still needs evidence, and multivitamin supplementation in an athlete with an adequate diet produces no performance benefit while some fat-soluble vitamins are harmful in excess. The most serious risk for tested athletes remains contamination: even though regulation and label rules apply, undeclared prohibited substances can enter a product, and strict liability makes the athlete responsible for what is in their sample regardless of intent. Supplements also displace attention and money from sleep, training and whole-diet factors that produce far larger effects.
The tension is that the products with the best evidence are marketed alongside those with none, under the same category name and often by the same retailers, so an athlete deciding rationally about creatine encounters the same claims and the same contamination risk as one buying an unevidenced product. The category makes the good decision and the bad one look alike.
The defensible position is that supplement use is justified only where three conditions hold together: a specific evidenced benefit for that athlete's event, a demonstrated deficiency or performance need that food cannot practically meet, and a batch-tested product from a recognised testing program. On that test creatine and caffeine are defensible for the sports they suit, targeted correction of a diagnosed deficiency is clearly justified, and the great majority of the remaining market is not.
A supplement is a product taken in addition to the normal diet intending to improve performance or recovery, and the issue is whether the measured benefit justifies the cost and risk, and whether the answer is the same for every product grouped under the term. For a small number the evidence is genuinely good: creatine reliably increases intramuscular creatine phosphate stores, improving repeated high-intensity efforts and supporting lean mass gains with a well-established safety profile in healthy adults; caffeine reduces perceived exertion and improves endurance and alertness at modest doses; protein supplements do not outperform food but deliver a known quantity conveniently when appetite is suppressed after training, supporting adherence; and correcting a genuine deficiency such as iron in female endurance athletes or vitamin D in indoor athletes produces real improvement. Evidence and regulation differ across product classes: food health claims must meet Food Standards Code substantiation requirements, while some performance-claim sports supplements are therapeutic goods under TGA rules and must be entered in the ARTG. Listed medicines rely on sponsor-held evidence and are not individually assessed by the TGA for efficacy before listing, while some other medicine classes receive pre-market assessment. These controls do not remove every risk: contamination and inaccurate contents remain possible, and a compliant product is not automatically safe or effective for every athlete. Multivitamin use by an athlete with an adequate diet produces no benefit while some fat-soluble vitamins are harmful in excess; and most seriously, a contaminated product can lead to a strict-liability anti-doping violation, because the athlete is responsible for whatever is in their sample regardless of intent. Supplements also displace attention and money from sleep, training and whole-diet factors producing far larger effects. The tension is that the best-evidenced products are marketed alongside unevidenced ones under the same category name and often by the same retailers, so the category makes a good decision and a bad one look alike. The defensible position is therefore that use is justified only where three conditions hold together: a specific evidenced benefit for that athlete's event, a need that food cannot practically meet, and a batch-tested product from a recognised testing program — on which test creatine, caffeine and targeted correction of a diagnosed deficiency are defensible and the great majority of the market is not.
Explain why an athlete may inadvertently commit an anti-doping violation through supplement use.
Explain asks for the mechanism by which an honest athlete ends up in violation. The answer turns on how the rule is written, not on the athlete's intent.
Plan: name the principle, build linked pairs through the supply chain and the rule, then answer directly.
Anti-doping codes operate on strict liability: an athlete is responsible for any prohibited substance found in their sample regardless of how it arrived there or whether they intended to take it. Intent may affect the sanction, but it does not affect whether a violation occurred.
Australian sports supplements may be foods under the Food Standards Code or therapeutic goods under TGA rules, depending on their ingredients, form and claims. Some oral sports-performance products that contain restricted ingredients—such as ingredients scheduled in the Poisons Standard or WADA Prohibited List—or come as tablets, capsules or pills (except glucose-only products) are declared therapeutic goods and must be entered in the ARTG before supply. Food health claims have substantiation rules; listed medicines require sponsors to hold evidence for their indications, although the TGA does not individually assess each listed medicine's efficacy before listing. The regulatory category and label still cannot guarantee that a particular batch is uncontaminated or that a claim demonstrates a performance benefit.
Contamination then occurs through the supply chain: raw ingredients may be sourced from suppliers who also handle prohibited compounds, and shared manufacturing equipment can transfer trace amounts between production runs, so a product formulated without a prohibited substance can still contain one.
Testing sensitivity closes the trap: modern assays detect quantities far below any pharmacologically active dose, so a trace contaminant that could not have improved performance is still sufficient to produce a positive result and therefore a violation.
An athlete can therefore commit a violation having read the label accurately, bought from a reputable retailer and intended no advantage — which is why the recognised mitigation is not care in reading labels but restricting use to products from independent batch-testing programs, and why many sporting organisations advise against non-essential supplementation altogether.
Anti-doping codes operate on strict liability: an athlete is responsible for any prohibited substance found in their sample regardless of how it arrived or whether they intended to take it, so intent may affect the sanction but not whether a violation occurred. Australian sports supplements may be foods under the Food Standards Code or therapeutic goods under TGA rules, depending on ingredients, form and claims. Some oral sports-performance products with restricted ingredients, including substances scheduled in the Poisons Standard or on the WADA Prohibited List, or products in tablet, capsule or pill form (except glucose-only products), must be entered in the ARTG before supply. Food health claims and therapeutic goods have different requirements, and listed medicines rely on sponsor-held evidence rather than individual pre-market efficacy assessment by the TGA. Neither category guarantees that a particular batch is free of contamination or that a supplement is safe and effective for every athlete. Contamination can occur through the supply chain: raw ingredients may come from suppliers who also handle prohibited compounds and shared manufacturing equipment can transfer trace amounts between production runs. Testing sensitivity then closes the trap: a trace contaminant can produce a positive result and therefore a violation even when it could not improve performance. An athlete can consequently commit a violation having read the label accurately, bought from a reputable retailer and intended no advantage — which is why independent batch-testing programs can reduce, but cannot remove, the risk, and why many sporting organisations advise against non-essential supplementation altogether.
Go back to card 01. On the evidence, caffeine and creatine sit above the protein powder and the multivitamin for a 17-year-old team-sport athlete — but the ranking was never the real question. For every one of the four, the answer is conditional on the athlete: caffeine helps someone who has trialled it, tolerates it and is not using it to cover a sleep problem; creatine helps someone already training hard in a sport where added mass is not a penalty; protein powder helps someone who cannot otherwise reach adequacy; and a multivitamin helps someone who is actually deficient. Write down what condition you attached to your top-ranked product, and whether you can now name a specific athlete for whom your bottom-ranked one would be the right choice.
Multiple choice · 5 questions
MC 1. The food-first principle states that:
- A. supplements should never be used by any athlete
- B. food should be eaten before any training session
- C. protein should be prioritised over carbohydrate
- D. nutritional needs should be met from food unless there is a specific reason they cannot be
MC 2. Caffeine improves performance mainly by:
- A. increasing the muscle's store of creatine phosphate
- B. acting on the central nervous system to reduce perceived effort and improve alertness
- C. increasing haemoglobin concentration
- D. replacing the need for sleep before competition
MC 3. Creatine supplementation is most likely to benefit:
- A. a sprinter in a structured resistance program, where added mass is not a penalty
- B. a marathon runner in the final week before a race
- C. an athlete in a weight-category sport close to the limit
- D. an athlete who trains inconsistently and rarely reaches maximal efforts
MC 4. Giving iron supplements to an athlete who is not iron deficient will:
- A. improve endurance performance by increasing oxygen carriage
- B. improve recovery between sessions
- C. produce no performance benefit, and excess iron can be harmful
- D. increase muscle hypertrophy from resistance training
MC 5. A supplement label lists a "proprietary performance blend" without stating its full contents. For an athlete subject to drug testing, the main problem is that:
- A. proprietary blends are always less effective than named ingredients
- B. the athlete cannot know what is in it, and remains responsible for any prohibited substance found in their sample
- C. proprietary blends are illegal to sell in Australia
- D. the price is likely to be higher than for a named product
Short answer · exam style
SA 1. Understand Band 4 Explain the difference between correcting a micronutrient deficiency and supplementing an athlete who is not deficient, using iron as your example. (4 marks)
SA 2. Analyse Band 5 Compare caffeine and creatine, referring to their mechanisms, the type of performance each supports, and one limitation of each. (6 marks)
SA 3. Evaluate Band 6 Discuss the use of supplements for improved performance in school-age athletes. Refer to micronutrients, protein and at least one named ergogenic aid, and weigh benefits against risks. (7 marks)
📖 Comprehensive answers (click to reveal)
Multiple choice: 1 → D. 2 → B. 3 → A. 4 → C. 5 → B.
Activity 1, indicative answers: 1 → Support, with medical management. Claim: correcting low iron will reduce fatigue and improve endurance performance. Mechanism: iron is a component of haemoglobin and myoglobin, so a deficiency impairs oxygen transport and use. Risk: excess iron is harmful, so dose and duration must be medically supervised and re-tested rather than self-managed; the cause of the deficiency also needs investigating. Judgement: this is the clearest legitimate case, because a diagnosed deficiency is a real problem that the supplement genuinely solves. 2 → Do not support, at least not yet. Claim: caffeine will reduce perceived effort and improve alertness, which is true. Mechanism: central nervous system. Risk: taken before training it will further disturb sleep in someone already on six hours, which worsens the underlying problem; adolescents are advised to limit caffeine; and side effects include anxiety and raised heart rate. Judgement: the athlete has a recovery problem, not a caffeine deficiency, and the intervention with the larger effect is the one in Lesson 15. Using caffeine here masks the signal that something needs fixing. 3 → Support, with conditions. Claim: creatine will support repeated maximal efforts and greater training volume. Mechanism: raises muscle creatine phosphate, so ATP is regenerated faster in very short maximal work and recovery between efforts improves. Risk: weight gain from water drawn into muscle, which does not matter for a sprinter but would in a weight-category sport; contamination, so a batch-tested product only; and it amplifies training rather than replacing it, which is satisfied here because the athlete already trains hard. Judgement: a reasonable choice, and the strongest of the four cases after the iron. 4 → Do not support. Claim: insurance against unidentified dietary gaps. Mechanism: none, in a replete athlete — the dose-response is flat through adequacy. Risk: cost, the possibility of exceeding safe intakes for some nutrients, and the opportunity cost of believing the nutrition problem is solved. Judgement: no. What would change the answer is a specific identified gap — a restricted diet, a diagnosed deficiency, or a medical reason — at which point it stops being insurance and becomes a targeted correction.
Activity 2, indicative answers: Claim 1 asserts causation with the phrase "clinically proven", but names no study, no comparison group, no population and no measured outcome; "proven" is not a standard any single study meets. Claim 2 quotes a percentage change in a recovery marker, which is not the same as a change in performance; you would need to know what the marker was, who was studied, whether there was a control condition, how variable the results were, and who funded the work. Claim 3 conceals the contents, so neither the dose of any ingredient nor the presence of a prohibited substance can be checked. Claim 4 is an appeal to testimonial: professional athletes are paid to endorse products, and use by anyone is not evidence of effect. Claim 5 asserts that more protein produces more muscle, which is false above an adequate intake and independently of a training stimulus. The most dangerous for a tested athlete is claim 3, because an undisclosed blend cannot be checked and the athlete remains responsible for whatever is found in their sample; batch testing is the only mitigation and even that is not absolute. The most misleading rather than merely unsupported is claim 2, because it presents a real number in a way designed to be read as a performance improvement when the measured outcome was a laboratory marker. A teammate's testimonial establishes that they believe it helped and, at most, that they improved; it cannot establish that the product caused the improvement, because nothing was controlled, training and other factors changed at the same time, and the placebo effect is real and measurable — which is precisely why controlled comparison exists.
SA 1 (4 marks): Role of iron [1]: it is a component of haemoglobin and myoglobin, so it is central to the transport of oxygen in blood and its use in muscle. In deficiency [1]: oxygen carriage and use are impaired, producing fatigue and reduced endurance performance, so correcting the deficiency restores capacity and improves performance. In a replete athlete [1]: additional iron produces no performance benefit, because oxygen transport was not the limiting factor, and excess iron can be harmful. The general shape [1]: the relationship between intake and performance is not linear — it rises steeply out of deficiency, flattens through adequacy, and can turn downwards in excess — which is why supplementation should follow testing and medical assessment rather than assumption.
SA 2 (6 marks): Caffeine [3]: acts on the central nervous system, reducing perceived effort and improving alertness, concentration and reaction time, so the effect is on how hard the work feels rather than on what the muscle can do [1]; it therefore benefits a wide range of performance, including endurance, repeated sprints and sports requiring sustained concentration [1]; its limitations include considerable individual variation with non-responders, side effects such as anxiety, tremor and gastrointestinal upset, and disturbed sleep if taken late, which damages the recovery of Lesson 15 [1]. Creatine [3]: increases the muscle store of creatine phosphate, the compound that rapidly regenerates ATP in very short maximal efforts, so more work can be done before that system is exhausted and recovery between efforts improves [1]; it therefore benefits repeated short maximal efforts and resistance training, where it supports greater training volume and hence greater adaptation over time [1]; its limitations include weight gain from water drawn into muscle, which penalises endurance and weight-category athletes, reduced response in athletes whose stores are already high, and the fact that it amplifies training rather than replacing it [1]. The contrast worth stating: caffeine changes perception acutely, creatine changes a metabolic store over weeks.
SA 3 (7 marks): Food first [1]: nutritional needs should be met from food unless there is a specific reason they cannot be, because food is familiar and does not introduce the additional contamination risk of a supplement; the legitimate exceptions are a diagnosed deficiency, a genuine practical constraint, and a specific ergogenic effect unavailable from ordinary food. Micronutrients [1]: correcting a diagnosed deficiency such as low iron improves performance because oxygen transport was impaired, while supplementing a replete athlete produces no benefit and can be harmful — the dose-response rises out of deficiency and then flattens. Protein [1]: adequate protein is necessary for the repair and hypertrophy that training stimulates, but above adequacy more protein does not produce more muscle, and most athletes eating enough total food already reach adequacy, so a powder is a matter of convenience rather than additional benefit. A named ergogenic aid [2]: for example caffeine, which acts on the central nervous system to lower perceived effort and improves a wide range of performance, but varies greatly between individuals, causes side effects, and disturbs sleep if taken late; or creatine, which raises muscle creatine phosphate and benefits repeated maximal efforts and resistance training, but adds mass and only amplifies training that is already being done. Risks [1]: contamination with undeclared substances, with the athlete remaining responsible for what is in their sample; regulation depends on classification and risk, with food health claims subject to substantiation requirements and therapeutic goods subject to TGA and ARTG requirements; real side effects and interactions, particularly for those under 18; and the opportunity cost of attention diverted from sleep, fuelling and consistent training. Judgement for school-age athletes [1]: apart from a medically managed deficiency, and possibly a practical recovery product, the case is weak — advice for adolescents is more cautious, long-term data is thinner, and the interventions in Lessons 6, 7 and 15 will produce a larger effect for the same effort. A response reaching the top band also notes that the placebo effect is real, so an athlete's own testimonial cannot establish that a product works.
This completes the fourth inquiry question. Lessons 14, 15 and 16 move outwards from fuelling a performance, to the recovery system that supports a week of them, to the products that are marketed as shortcuts through both.
Two ideas do the heavy lifting. The dose-response shape — steep out of deficiency, flat through adequacy, sometimes turning down — answers most micronutrient and protein questions on its own. And the five-step discussion — claim, mechanism, evidence, risk, judgement — is the structure that turns a list of products into an argument. Lesson 17 begins the final inquiry question, on sustained movement and performance, starting with biomechanics.
Mark lesson as complete
Tick when you've finished the practice and review.