Interpret heart-rate change and recovery data
Calculate activity increases and describe recovery without making unsupported health judgements.
Exam scope and assessment notes
Core and Extended · Biology 0970, 2026–2028. Use the stated specimen features and evidence. Diagrams are schematic. Written practice is self-checked; human subject-teacher review, supervised practical competence and cumulative assessment remain pending. Cambridge states that IGCSE 0970 has the same subject content as IGCSE 0610, with 9–1 grading. This StudyForA pathway maps the 2026–2028 syllabus only. This 9–1 graded qualification is available only in a limited number of administrative zones. Confirm that your centre can enter you for this code and exam series with Cambridge International. Cambridge has published a separate syllabus for 2029. StudyForA has not reconciled that version yet; this page supports exams in 2026, 2027 and 2028 only.
Before you begin
- Recall mean, rate units and percentage change.
Work on paper. Try each question before revealing help, and explain why your method works.
Quick readiness check
What is the mean of 70, 72 and 74?
What you will learn
- Compare activity with the resting baseline
- Describe the pattern and its limits
Activity and recovery records
| Trial | Rest | After activity | After 2 min |
|---|---|---|---|
| 1 | 70 | 118 | 82 |
| 2 | 72 | 120 | 84 |
| 3 | 74 | 122 | 86 |
| Mean | 72 | 120 | 84 |
Compare activity with the resting baseline
The supplied teaching table shows three trials: resting rates 70, 72 and 74 beats per minute, immediate post-activity rates 118, 120 and 122, and two-minute recovery rates 82, 84 and 86. These are invented teaching records, not measurements from a named learner.
The mean resting rate is (70 + 72 + 74) ÷ 3 = 72. The immediate mean is 120 and the recovery mean is 84 beats per minute. The immediate increase above rest is 120 − 72 = 48 beats per minute. Keep an increase and a total rate separate.
Describe the pattern and its limits
The records show a rise after activity, followed by a fall towards the resting baseline during recovery. Recovery at two minutes is 84, still 12 beats per minute above the mean baseline, so the data do not show complete return to rest by that time.
A percentage increase uses the resting value as the denominator: 48 ÷ 72 × 100 ≈ 66.7%. A higher rate alone does not show disease or prove one learner is fitter than another. The design, activity intensity, timing and baseline matter, and the table supports only the stated comparison.
Pause and explain
What does the recovery mean of 84 show?
Worked example
Calculate the mean immediate increase from the supplied table.
Show the worked solution
- Mean resting rate is 72 and mean immediate rate is 120.
- Subtract baseline from immediate rate: 120 − 72.
Answer 48 beats per minute; immediate mean rate itself is 120 beats per minute.
Try a topic test
Choose Easy, Normal or Difficult. Save your answers and open worked review after finishing.
Test this topic →From guided practice to a new situation
Write your answer and reasoning first. Use a hint only if you are stuck. The model solution is for self-checking; your written work is not automatically marked.
Calculate the mean resting and immediate rates, then the increase.
Give me a hint
Find the means before comparing them.
Compare my reasoning
- Rest: 216 ÷ 3 = 72; immediate: 360 ÷ 3 = 120.
- Increase: 120 − 72 = 48.
Rest 72; immediate 120; increase 48 beats per minute.
Look for these in your work
- Correct means
- Distinguish rate and increase
Calculate the percentage increase from mean rest to immediate post-activity rate to one decimal place.
Give me a hint
Divide the change by the resting rate.
Compare my reasoning
- Change is 48 and baseline is 72.
- 48 ÷ 72 × 100 = 66.666…%.
66.7% increase.
Look for these in your work
- Use baseline denominator
- Correct rounding
A report says “the heart rate fully recovered within two minutes and the person has no heart disease”. Evaluate both claims using the table.
Give me a hint
Check the recovery value and the scope of the evidence.
Compare my reasoning
- 84 remains above the 72 resting mean.
- Supplied rate data do not establish a medical diagnosis.
Neither claim is established: recovery is incomplete at two minutes, and these records do not diagnose health.
Look for these in your work
- Compare recovery with baseline
- Respect the diagnostic limit
Common mistakes
- Calling 48 the final heart rate.
- Claiming the two-minute measurement equals rest.
What can you explain now?
What does the recovery mean of 84 show?
Compare with the explanation
Rate fell but remained 12 beats per minute above rest
84 − 72 = 12.
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Make it stick
Describe the rise and recovery in words, then distinguish the total rate from its increase.
If you needed the solution, close it and solve the problem again from a blank page. A correct answer is stronger when you can explain the reason for each step.