What makes up fitness, and how do we measure each part reliably?
The components of physical and skill-related fitness, their definitions and importance to performance, and valid, reliable fitness tests for each, including the evaluation of test data.
A focused WJEC A-Level PE answer on the components of physical and skill-related fitness, their definitions and importance, the recognised fitness tests for each, and how to judge validity, reliability and the use of test data.
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What this dot point is asking
WJEC wants you to define the components of physical and skill-related fitness, explain why each matters to performance, name a valid and reliable test for each, and evaluate test data in terms of validity, reliability and how the results should be used.
Components of fitness
Each component matters differently to different sports. A marathon runner relies on aerobic capacity; a weightlifter on maximal strength; a gymnast on balance, flexibility and power; a games player on agility, speed and reaction time. Defining each precisely is essential: for instance, power is the product of strength and speed (work done per unit time), and agility is changing direction quickly under control.
Tests for each component
A test should be matched to the component and follow a standard protocol:
- Aerobic capacity: the multi-stage fitness test (bleep test) estimates VO2 max; a direct VO2 max test using gas analysis is the most valid.
- Muscular strength: the grip dynamometer (hand strength) or a one-repetition maximum.
- Muscular endurance: the press-up or sit-up test counts repetitions to fatigue.
- Flexibility: the sit-and-reach test measures trunk and hamstring flexibility in centimetres.
- Speed: a 30 m or 40 m sprint timed with a stopwatch or timing gates.
- Power: the vertical jump (Sargent) test or standing broad jump.
- Agility: the Illinois agility run, timed through a cone course.
- Balance: the stork stand test, timing how long balance is held on one foot.
- Reaction time: the ruler drop test measures the distance a falling ruler is caught.
Results are compared against normative data tables for the performer's age and sex to rate the performance.
Validity, reliability and using the data
A test can be reliable but not valid, or vice versa. The multi-stage fitness test, for example, is reasonably reliable if standardised, but only predicts VO2 max rather than measuring it directly, so a direct gas-analysis test is more valid. To improve reliability, the protocol is standardised (same surface, equipment, instructions and motivation) and the test is repeated. Test data is then used to compare against norms, identify strengths and weaknesses, set training targets, and monitor progress by retesting after a training block.
Examples in context
Example 1. Sport-specific testing. A netball coach prioritises agility and reaction-time tests because the game demands repeated rapid changes of direction and quick responses, not steady aerobic running. This shows fitness testing must be matched to the demands of the sport.
Example 2. Monitoring a training block. A swimmer is retested with the same protocol after a six-week aerobic mesocycle, and the improvement in estimated VO2 max confirms the training worked. WJEC uses this to show fitness testing is a tool for evaluating training, not a one-off.
Try this
Q1. Define muscular endurance and name a test for it. [2 marks]
- Cue. The ability of a muscle or muscle group to contract repeatedly without fatigue; for example the press-up or sit-up test counting repetitions to fatigue.
Q2. Explain the difference between validity and reliability of a fitness test. [2 marks]
- Cue. Validity is whether the test measures the component it claims to; reliability is whether it gives consistent results when repeated under the same conditions.
Q3. Explain how a coach could improve the reliability of a fitness test. [3 marks]
- Cue. Standardise the protocol (same equipment, surface, instructions and motivation), warm up consistently, and repeat the test under the same conditions taking the best or mean result.
Exam-style practice questions
Practice questions written in the style of WJEC exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
WJEC 20194 marksDefine agility and describe a recognised test that could be used to measure it, explaining how the result is obtained.Show worked answer →
Agility is the ability to change direction quickly and under control while maintaining balance and speed.
A recognised test is the Illinois agility run. The performer sprints through a set course of cones (a fixed layout of length and width) that requires repeated changes of direction.
The time taken to complete the course is recorded with a stopwatch and compared against normative data tables for the performer's age and sex to rate their agility.
Markers reward a correct definition, a recognised agility test, the method (timed run through the cone course), and comparison with normative data.
WJEC 20216 marksA coach uses the multi-stage fitness test to measure aerobic capacity. Evaluate the validity and reliability of this test and suggest how results should be used.Show worked answer →
The multi-stage fitness test (bleep test) estimates VO2 max from the level and shuttle reached when the performer can no longer keep pace with the bleeps.
Reliability: it is reliable if the procedure is standardised (same surface, same audio, same encouragement) and repeated under the same conditions, but motivation and pacing can vary between attempts.
Validity: it is a maximal test that uses running, so it has reasonable ecological validity for games players, but it only estimates VO2 max rather than measuring it directly (a direct gas-analysis test is more valid). It is also a sub-maximal predictor, so it relies on the performer running to exhaustion.
Use of results: compare against normative data, set training targets, and retest after a training block to monitor progress, but treat the VO2 max figure as an estimate.
Markers reward describing the test, discussing both reliability and validity with reasons, and a sensible use of the data.
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