Worked example · PE · Year 8
DCF: Data and computational thinking → Data and information literacy
A secure Year 8 response, annotated so you can see which success criterion each part meets. It is also your answer key: the four averages are 73, 155, 114 and 41. Show it after pupils have plotted their own graph.
| Day | Resting (bpm) | Straight after (bpm) | After 1 minute (bpm) | Recovery (beats) | Working |
|---|---|---|---|---|---|
| Monday | 74 | 158 | 118 | 40 | 158 − 118 |
| Tuesday | 72 | 152 | 110 | 42 | 152 − 110 |
| Wednesday | 76 | 165 | 127 | 38 | 165 − 127 |
| Thursday | 77 | 160 | 125 | 35 | 160 − 125 |
| Friday | 73 | 150 | 106 | 44 | 150 − 106 |
| Saturday | 70 | 146 | 100 | 46 | 146 − 100 |
| Sunday | 69 | 154 | 112 | 42 | 154 − 112 |
| Average | 73 | 155 | 114 | 41 | 511 ÷ 7, 1085 ÷ 7, 798 ÷ 7, 287 ÷ 7 |
Every recovery figure is the subtraction shown alongside it, and all four averages divide exactly, so the arithmetic checks out. Evidences criterion 1.
I counted 19 beats in 15 seconds, so 19 × 4 = 76 bpm. That is inside the normal resting range of 60 to 100 bpm, and 3 beats a minute above Ffion's weekly average of 73. That gap is smaller than the gap between her own best and worst day (69 to 77), so I would not read anything into it at all.
Uses the 15-second method correctly and compares the two figures against the week's own variation rather than declaring a winner. Evidences criteria 1 and 3.
Three lines on one scale, each distinguishable without colour alone, plus a key, labelled axes and a title naming the test. The vertical gap between the top two lines is the recovery. Evidences criterion 2.
(a) She recovered fastest on Saturday, dropping 46 bpm in the first minute, from 146 to 100. She recovered slowest on Thursday, dropping only 35 bpm, from 160 to 125. The difference between her best and worst day is 11 beats per minute.
(b) No. Her resting rate only moves between 69 and 77 bpm, which is a range of 8 bpm, and that is ordinary day-to-day variation rather than a trend. One week is nowhere near long enough for training to change a resting heart rate — that takes weeks or months of regular exercise. To show a real change she would need to keep the same step test and the same measuring routine and compare, say, September with November.
(c) On Thursday she had slept only 5 hours. Her resting rate was the highest of the week at 77 bpm and her recovery the worst at 35 beats, which fits: being short of sleep raises resting heart rate and makes the same work feel harder. It is a reminder that a heart rate reading measures the state of the whole person that day, not only their fitness.
(d) Estimated maximum heart rate = 220 − 13 = 207 bpm. On Wednesday she reached 165 bpm, and 165 ÷ 207 = 0.797, so about 80% of her estimated maximum. That was her football training day, which is why it is the highest reading of the week. Saturday's 146 bpm is 146 ÷ 207 = 0.705, about 71%, which is the easiest day.
Values are quoted with units, the flat resting line is interpreted honestly instead of being turned into a fitness claim, the outlier is explained from the data, and the percentages are worked out correctly. Evidences criteria 3, 4 and 5.