Slide 1 of 7 · Settling starter · Science · Year 9
5 minutesEvaluating Online Claims about Sports Recovery Drinks
Social media posts often use scientific-looking graphs and percentages to sell fitness products. Today you will test a viral influencer post for “HydraMax Pro” against a real laboratory trial and nutrition table.
While the register is called: write your name, class and date on your worksheet, then read Section 1 of the stimulus sheet and answer the starter question in rough.
Starter question: Look at the fine print at the bottom of @FitWithRhys_CW’s social media post. Spot two warning signs that this post might not be neutral scientific advice.
Slide 2 of 7 · Today’s brief and key words · Science · Year 9
5 minutesToday’s brief and key vocabulary
Your school sports council has been asked whether to stock HydraMax Pro in the gym vending machine at £2.80 a bottle. You will audit the method, calculate the real percentage changes, expose a misleading graph, and write a science fact-check post.
Method and bias
- Sample size: how many people were tested (6 vs 60).
- Control group: a comparison group drinking plain water or squash.
- Funding bias: when the company selling the product pays for the test.
Data and graphs
- Percentage change: (change ÷ original value) × 100.
- Truncated axis: a vertical axis that does not start at zero, exaggerating small differences.
Slide 3 of 7 · Step 1: Method and credibility audit · Science · Year 9
10 minutesStep 1: Auditing the two trials
Compare the influencer’s mini-test (Section 1) with the independent Cardiff Sports Science Lab trial (Section 2). We have completed the first row on the board together.
| Feature | Influencer post (HydraMax mini-test) | Independent lab trial | Why this matters for validity |
|---|---|---|---|
| Sample size | 6 gym members | 60 runners (20 per group) | 6 is too small; one unusual person skews the average. 60 reduces the effect of chance. |
| Control group | Complete this row and the remaining rows on your worksheet... | ||
Slide 4 of 7 · Step 2: Percentage change and nutrition · Science · Year 9
10 minutesStep 2: Checking the maths and the sugar content
Use the formula below to test whether sprint times really improved by 40%, or by only 2%. Show every step of your calculation.
Formula: Percentage change = (change ÷ original value) × 100
Worked example (Water group sprint time): Original = 50.0 s, After = 49.5 s.
Change = 50.0 − 49.5 = 0.5 s improvement.
Percentage improvement = (0.5 ÷ 50.0) × 100 = 1.0%.
Now calculate the percentage improvement for HydraMax Pro (50.0 s to 49.0 s) and diluted orange squash (50.0 s to 49.1 s), then complete the sugar and cost calculations in Step 2(b) and 2(c).
Slide 5 of 7 · Step 3: Truncated graph & fact-check post · Science · Year 9
12 minutesStep 3 and Step 4: Exposing the graph and writing your fact-check
First complete Step 3 by comparing the bar heights on Graph A (truncated axis covering 49.6 s to 48.8 s) and Graph B (full axis starting at 0 s). Then write your 4-part science fact-check reply in Step 4.
Structure for your Step 4 fact-check post (100 to 140 words):
- Headline verdict: State clearly that the “40% faster recovery” claim is misleading.
- Method & bias: Contrast the 6-person paid test with the 60-person double-blind lab trial.
- Real numbers & graph trick: Quote the 2.0% vs 1.8% sprint improvement and explain the truncated y-axis starting at 49.6 s.
- Recommendation: Give the school sports council a clear decision using the 36 g sugar figure and £2.80 price.
Slide 6 of 7 · Partner and self check · Science · Year 9
5 minutesCheck your work against the success criteria
Swap worksheets with your partner or check your own sheet carefully. Tick each box in the success criteria table only if you can point to the exact evidence on the page.
- Have you explained why sample size (6 vs 60), a control group, and funding independence matter?
- Have you shown the full working for the 2.0% and 1.8% sprint improvements and the 36.0 g (120%) sugar calculation?
- Have you explained how the truncated axis on Graph A distorts a 2% difference?
- Does your Step 4 fact-check post quote at least four figures from the data and keep a formal, objective scientific tone?
Slide 7 of 7 · Plenary quick-check · Science · Year 9
3 minutesPlenary: Quick-check answers
Check your key numbers before handing in your worksheet.
| Question | Correct answer |
|---|---|
| Real sprint time improvement with HydraMax Pro vs squash | 2.0% (50.0 s to 49.0 s) vs 1.8% for diluted squash with a pinch of salt (50.0 s to 49.1 s) |
| Sugar in one 500 ml bottle of HydraMax Pro | 36.0 g (7.2 g × 5), which is 120% of the 30 g NHS daily maximum for free sugars |
| How Graph A exaggerates the result | Truncated y-axis covers only 49.6 s to 48.8 s instead of starting at 0 s, making a 2.0% difference look 5 times bigger (50 mm vs 10 mm bar) |
| Cost comparison per 500 ml serving | £2.80 vs £0.14 (HydraMax Pro is 20 times more expensive) |