Training schedule

The heptathlon is an athletics competition consisting of 7 events. Can you make sense of the scoring system in order to advise a heptathlete on the best way to reach her target?

Age

14 to 16

Challenge level

Secondary

ALGEBRA

Equations & Formulae

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Problem

Training Schedule printable sheet

The heptathlon is an athletics competition consisting of 7 events:

200m sprint
800m run
100m hurdles
high jump
long jump
shot put
javelin

The scoring system uses two types of equation:

$y=a(b-x)^c$ (1)

$y=a(x-b)^c$ (2)

$a$, $b$ and $c$ are constants, $x$ is the competitor's time or distance and $y$ is the number of points they are awarded.

Which events do you think use equations of type (1)? Why?

Which events do you think use equations of type (2)? Why?

For the running events, $x$ is the time in seconds. For the jumping events, $x$ is the distance/height in centimetres. For the throwing events, $x$ is the distance in metres.

The values for a, b, and c in each event are given below:

Event	a	b	c
200 meters	4.99087	42.5	1.81
800 meters	0.11193	254	1.88
100 metres hurdles	9.23076	26.7	1.835
High Jump	1.84523	75	1.348
Long Jump	0.188807	210	1.41
Shot Put	56.0211	1.5	1.05
Javelin Throw	15.9803	3.8	1.04

In the table below are the best times and distances of an Olympic hopeful in training, as well as the World Records for each heptathlon event (as of April 2011).

Event	Olympic hopeful	World records
200m	25.34s	21.34s
800m	2min 13.00s	1min 53.28s
100m hurdles	13.65s	12.21s
High jump	1.43m	2.09m
Long jump	5.67m	7.52m
Shot put	12.45m	22.63m
Javelin	45.05m	72.28m

In order to work out a suitable training schedule for her, work out her score in each event.

The world record for each event can be taken as a theoretical maximum/minimum.

Suppose she could close the gap between her current performance in each event and the world record by 10%. How would that affect her progress towards her target heptathlon score of 6000 points?

Instead, she could put together an alternative training schedule aiming to close the gap by 20% in some events. However, this extra training would have to be at the expense of her training for other events (so for every event she chooses to improve by 20%, she must choose another where she forfeits the 10% gain and instead maintains her current level).

Could this training strategy lead to a better score?

Can she reach the target of 6000 points?

NOTES AND BACKGROUND

Data source: http://en.wikipedia.org/wiki/Heptathlon

Teachers' Resources

Why do this problem?

When we watch sports coverage of the multi-discipline events such as the heptathlon, the scoring mechanism is not usually made explicit. This problem explores some of the maths behind the scoring system and invites students to optimise an athlete's performance by choosing a suitable training schedule. Along the way, students can practise substituting into formulas, make sense of functions, and use spreadsheets to repeat routine calculations quickly.

Possible approach

Set the scene by introducing the seven heptathlon events (perhaps asking students if they can name the events). Then display the two equations:

$y=a(b-x)^c$ (1)

$y=a(x-b)^c$ (2)

"These are the equations used to calculate the points scored in the different heptathlon events. Why do you think there are two equations? Which equation do you think is used for each event?"

Give students time to discuss their answers in pairs, and then share as a class.

Now display the rest of the problem and/or hand out this worksheet. Before they get started, take some time to talk through the problem, and check students understand the task.

As there is quite a bit of repeated computation involved, it may be useful to use spreadsheets if computers are available. Alternatively, students could work in small groups and share out the calculations among themselves.

Finally, gather the class together to share the different training schedules they have devised.

Key questions

What happens to the number of points given by each equation as $x$ increases/decreases?

Possible support

Students may opt to use a calculator to solve this problem, but it is much more efficient to use a spreadsheet. In order to make the most of the task, it may be worthwhile spending some time with the whole class talking about how to set up formulas in a spreadsheet and how to make changes to investigate different training schedules.

Possible extension

Imagine the heptathlon was to become an octathlon. Choose an eighth event and design and justify a scoring formula which would allocate points consistent with the other events.

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