Testing aerobic endurance and body composition – Physical Fitness (Senior 6 Physical Education) | Ganzaa

Physical Fitness

Lessons

Senior 6 · Physical Education

Physical Fitness

4 lessons

Lesson 2 of 4

Testing aerobic endurance and body composition

30 min

Measuring the engine

The best single measure of aerobic fitness is VO₂max, the most oxygen the body can take in and use each minute during hard exercise. In a laboratory it is measured by collecting a runner's breath on a treadmill. A school has no such laboratory, but it has a field, cones, a tape measure and a phone that can play a recording, and that is enough for two well-studied field tests that estimate VO₂max: the 20 m shuttle run and the Cooper 12-minute run. This lesson also covers body composition, using the body mass index (BMI), and its limits.

Definition

VO₂max: the maximum rate at which the body can take in and use oxygen, in millilitres of oxygen per kilogram of body mass per minute (mL kg⁻¹ min⁻¹).

Field test: a fitness test that needs little equipment and can test many people at once outside a laboratory.

Maximal test: a test in which the person works until they can go no further.

Body mass index (BMI): body mass in kilograms divided by the square of height in metres, used to screen for under- and over-weight.

Resting heart rate: the number of heartbeats per minute at complete rest; it usually falls as aerobic fitness improves.

The 20 m shuttle run (multistage fitness test)

The test was designed by Luc Léger and colleagues (1988). Runners go back and forth between two lines 20 m apart, keeping pace with beeps from a recording. Each minute the beeps come closer together, so the runner must go faster. The score is the last level and shuttle completed, which gives the final speed. Several versions of the recording exist, with slightly different speeds, so always note which version you used and use the same one when you retest.

Estimating VO₂max (Léger and others, 1988), with $S$ the final speed in km/h and $A$ the age in years:

\text{Ages 6 to 18:}\quad \mathrm{VO_2max} = 31.025 + 3.238\,S - 3.248\,A + 0.1536\,S A

\text{Adults:}\quad \mathrm{VO_2max} = -24.4 + 6.0\,S

The Cooper 12-minute run

On a measured track, run (or walk if necessary) as far as possible in 12 minutes. Cooper (1968) showed that the distance $d$ , in metres, gives an estimate of VO₂max:

\mathrm{VO_2max} = \frac{d - 504.9}{44.73}

Both tests are maximal: screen pupils first, choose a cool time of day, and stop anyone who feels chest pain, faint or dizzy.

Rating (illustrative, ages 16 to 19)	Shuttle run level, boys	Shuttle run level, girls	Cooper distance, boys	Cooper distance, girls
Excellent	12 or more	10 or more	over 3,000 m	over 2,300 m
Good	10 to 11	8 to 9	2,700–3,000 m	2,100–2,300 m
Average	8 to 9	6 to 7	2,300–2,699 m	1,800–2,099 m
Below average	6 to 7	4 to 5	2,100–2,299 m	1,700–1,799 m
Poor	5 or fewer	3 or fewer	under 2,100 m	under 1,700 m

These ratings are illustrative, for teaching only. Published norms differ between populations, ages and test versions; a school can build its own norms by recording its pupils' results over several years.

Heart rate and body composition

Resting heart rate: count the pulse at the wrist (radial) for 60 seconds after at least 5 minutes of sitting quietly, or on waking. Retest under the same conditions.
Maximum heart rate is often estimated as $220 - \text{age}$ , the formula you used in Senior 3. A study of many adults by Tanaka and colleagues (2001) found $208 - 0.7 \times \text{age}$ more accurate. Both are only estimates: real values vary by 10 or more beats per minute between people of the same age.
BMI $= \frac{\text{mass (kg)}}{\text{height (m)}^2}$ . The World Health Organization classifies adults as underweight below 18.5, normal weight from 18.5 to 24.9, overweight from 25.0 to 29.9 and obese at 30.0 or more. For young people aged 5 to 19, WHO uses BMI-for-age charts instead, because BMI changes as children grow.
Limits of BMI: it cannot tell fat from muscle, so a muscular athlete may be classed as overweight, and it says nothing about where fat is stored. Waist measurement adds information about fat around the abdomen.

Worked example

Worked example 1: from shuttle run to VO₂max. A 17-year-old stops at level 7 (final speed 11.5 km/h). Estimate his VO₂max.

\mathrm{VO_2max} = 31.025 + 3.238(11.5) - 3.248(17) + 0.1536(11.5)(17)

= 31.025 + 37.237 - 55.216 + 30.029 = 43.1\ \mathrm{mL\,kg^{-1}\,min^{-1}}

At level 7, each 20 m must be covered in $\frac{20}{11.5 \div 3.6} = 6.3\,\mathrm{s}$ . On the illustrative table he is "below average" for his age; his own next result is the more useful comparison.

Worked example

Worked example 2: Cooper run. Aline runs 2,600 m and Eric 2,200 m in 12 minutes.

Aline: $\frac{2600 - 504.9}{44.73} = 46.8\ \mathrm{mL\,kg^{-1}\,min^{-1}}$ .
Eric: $\frac{2200 - 504.9}{44.73} = 37.9\ \mathrm{mL\,kg^{-1}\,min^{-1}}$ .
Each extra 100 m in the test adds $\frac{100}{44.73} = 2.2$ units to the estimate. The estimate assumes a steady, all-out effort: a pupil who walks the first half because they paced badly scores lower than their true fitness.

Worked example

Worked example 3: interpreting BMI. Two adults: (a) 62 kg, 1.70 m tall; (b) a rugby forward of 81 kg, 1.75 m tall.

(a) $\frac{62}{1.70^2} = \frac{62}{2.89} = 21.5$ : in WHO's normal range.
(b) $\frac{81}{1.75^2} = \frac{81}{3.0625} = 26.4$ : "overweight" by the WHO cut-off.
Analysis: a rugby forward carries a lot of muscle, so BMI may overstate his fatness. A waist measurement or skinfold test would show whether the extra mass is fat or muscle.

Video: "20 Meter Shuttle Run (Beep Test)", joinLASD. A demonstration of runners keeping pace with the beeps between two lines 20 m apart; notice how they turn on the line and do not set off before the beep.

Warning

Common mistakes. Treating the VO₂max from a field test as exact: it is an estimate. Comparing results from different versions of the beep recording. Starting fast in the Cooper run and walking later. Calling a muscular athlete "overweight" from BMI alone, or using adult BMI cut-offs for a 15-year-old. Running a maximal test on a hot afternoon without water.

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Practice

What does VO₂max measure, and in what units?
Describe the set-up and scoring of the 20 m shuttle run.
A runner's final speed is 13.0 km/h. How long does she have to cover each 20 m at that level?
Use the adult equation to estimate VO₂max for a final speed of 12.0 km/h.
Estimate VO₂max for a Cooper distance of 2,850 m.
Calculate the BMI of a person of 55 kg and 1.62 m, and classify it using the WHO adult categories.
Compare the estimates of maximum heart rate for a 17-year-old from $220 - \text{age}$ and $208 - 0.7 \times \text{age}$ .
A school wants to test 120 pupils' aerobic fitness in one PE lesson. Evaluate whether the shuttle run or the Cooper run is more practical.

Show answersHide answers

The maximum rate of oxygen uptake and use; mL of oxygen per kg of body mass per minute.
Two lines 20 m apart on a flat, non-slip surface; runners keep pace with recorded beeps that speed up each minute; a warning for the first missed line and the test ends after two misses in a row; the score is the last level and shuttle completed.
$\frac{20}{13.0 \div 3.6} = 5.5\,\mathrm{s}$ .
$-24.4 + 6.0 \times 12.0 = 47.6\ \mathrm{mL\,kg^{-1}\,min^{-1}}$ .
$\frac{2850 - 504.9}{44.73} = 52.4\ \mathrm{mL\,kg^{-1}\,min^{-1}}$ .
$\frac{55}{1.62^2} = \frac{55}{2.6244} = 21.0$ : normal weight.
$220 - 17 = 203$ beats per minute; $208 - 0.7 \times 17 = 196$ beats per minute. They differ by about 7; both are estimates.
The Cooper run needs a measured track and a recorder for each runner's laps, but many pupils can run at once. The shuttle run needs only a 20 m lane per small group and is easy to score, but takes up to 20 minutes per group. With limited space and helpers, running the Cooper test in two big groups, with partners counting laps, may be the more practical choice; either way, the result is an estimate.

Remember

Shuttle run: 20 m, 8.5 km/h rising 0.5 km/h a minute; two misses end it.
Cooper: $\mathrm{VO_2max} = \frac{d - 504.9}{44.73}$ .
BMI = mass ÷ height²; WHO adult normal range 18.5 to 24.9; BMI-for-age under 19.
Field tests give estimates; compare like with like.

Sources and credits

Léger LA, Mercier D, Gadoury C and Lambert J, "The multistage 20 metre shuttle run test for aerobic fitness", Journal of Sports Sciences 6 (1988) 93–101: protocol and VO₂max equations.
Cooper KH, "A means of assessing maximal oxygen intake", Journal of the American Medical Association 203 (1968) 201–204: the 12-minute run equation.
Tanaka H, Monahan KD and Seals DR, "Age-predicted maximal heart rate revisited", Journal of the American College of Cardiology 37 (2001) 153–156.
Obesity and overweight, World Health Organization fact sheet: BMI categories for adults and BMI-for-age for children and adolescents.
Photo: Peterson SFB students aim high in new Presidential Fitness Test pilot, U.S. Space Force, public domain.
Video: "20 Meter Shuttle Run (Beep Test)", joinLASD, embedded from YouTube.
Shuttle-run diagram, illustrative norms, worked examples and practice: written by Ganzaa.

1Measuring the engine

2The 20 m shuttle run (multistage fitness test)

3The Cooper 12-minute run

4Heart rate and body composition

Measuring the engine

The 20 m shuttle run (multistage fitness test)

The Cooper 12-minute run

Heart rate and body composition