Components of fitness: health-related components (aerobic capacity, muscular strength, muscular endurance, flexibility, body composition) and skill-related components (speed, power, agility, coordination, balance, reaction time), their assessment and their prioritisation for a chosen activity

What this dot point is asking

QCAA wants you to know the components of fitness, the validated tests used to measure them, and how to prioritise the components that matter most for a chosen physical activity. A strong Unit 4 answer is not a definitions dump; it identifies the activity, names the dominant components based on the activity's measured demands, recommends a valid test for each, and justifies the prioritisation. The IA3 task explicitly asks for this kind of activity-specific reasoning.

The answer

Health-related components of fitness

These five components are linked to general health and disease prevention as well as performance.

• Aerobic capacity (cardiorespiratory endurance). The ability of the cardiovascular and respiratory systems to supply oxygen for sustained activity, usually expressed as VO2 max in millilitres of oxygen per kilogram of body mass per minute. It is the dominant component for endurance sports.
• Muscular strength. The maximum force a muscle or muscle group can produce in a single contraction. Typically tested with a one-repetition maximum (1RM) lift.
• Muscular endurance. The ability of a muscle to sustain or repeat contractions against a sub-maximal load. Tested by counting repetitions to fatigue or by sustained-contraction time.
• Flexibility. The range of motion available at a joint. Tested with the sit-and-reach (for hamstrings and low back) or goniometric measurement at individual joints.
• Body composition. The proportion of body mass that is fat versus fat-free mass. Tested with skinfold calipers (in trained hands), bioelectrical impedance (less accurate), or DEXA in research settings.

Skill-related components of fitness

These six components are about sporting performance rather than general health.

• Speed. The rate at which a body or body part can move over a distance. Tested with timed sprints (10, 20, 40 metre sprints are common).
• Power. Force times speed, the rate of doing work. Tested with the vertical jump (countermovement or Sargent jump) or the standing long jump.
• Agility. The ability to change direction quickly while maintaining control. Tested with the Illinois Agility Test, the 5-0-5 test, the T-test, or the AFL Agility Test.
• Coordination. The ability to use multiple body parts together smoothly. Tested with the alternate-hand wall-toss test or sport-specific assessments.
• Balance. The ability to maintain equilibrium, either static (held position) or dynamic (during movement). Tested with the stork stand (static) or the Y-balance test (dynamic).
• Reaction time. The time from a stimulus to the start of a movement. Tested with the ruler-drop test or with electronic timing gates and a light or sound stimulus.

Validity, reliability, and specificity of fitness tests

Choosing a test is not arbitrary. Three criteria matter.

• Validity. The test measures the component it claims to measure. The 1RM bench press is a valid test of upper-body strength; it is not a valid test of upper-body endurance.
• Reliability. The test gives consistent results across repeated administrations with the same person. Reliability depends on standardised protocol, warm-up, and tester experience.
• Specificity. The test reflects the demands of the activity. The Yo-Yo Intermittent Recovery Test is more specific to AFL or soccer than a steady-state treadmill VO2 max because it includes the start-stop pattern of the sport.

Strong Unit 4 responses name the test, state why it is valid for the component, and explain why it is appropriate for the chosen activity.

Prioritising components for a chosen activity

Every activity has a fitness profile. The Unit 4 method is:

1. Describe the activity's demands using verifiable data (work-rest ratio, distance covered, number of high-intensity bursts, contact load).
2. Identify which components dominate (usually three to five components).
3. Choose a validated test for each priority component.
4. Set the assessment schedule (pre-season baseline, mid-season check, post-season).

Worked profiles:

• Marathon runner. Aerobic capacity is the dominant component. Muscular endurance in the legs and body composition also matter. Power, speed, and agility are low priority.
• AFL midfielder. Aerobic capacity, anaerobic power (repeat-sprint), agility, and muscular strength all matter. Flexibility supports injury reduction. Reaction time supports contested play.
• Powerlifter. Muscular strength is dominant. Power matters in the explosive phase of the lift. Aerobic capacity, agility, and reaction time are low priority for the sport, though useful for general health.
• Tennis player. Aerobic capacity, anaerobic power (especially repeat-effort), speed, agility, coordination, and reaction time all matter. The profile is mixed because matches mix long rallies, short bursts, and constant decision-making.
• Wheelchair basketball player (NWBL). Upper-body muscular strength and endurance, anaerobic power, aerobic capacity (chair-based), agility (chair handling), reaction time, and coordination dominate. Test selection uses wheelchair-specific protocols.

Australian context for fitness profiling

Australian institutions publish reference data and protocols that students can draw on.

• The Australian Institute of Sport (AIS) maintains physiological reference values and protocols for elite athletes, with sport-specific profiles for many Olympic and team sports.
• AusPlay (Sport Australia) reports participation rates rather than physiological data, but it grounds the population-level discussion in real Australian numbers.
• Sport-specific bodies (the AFL, NRL, and Cricket Australia high-performance units) publish or release general demand data through coach-education materials and conference presentations.

When citing year-pinned data, hedge with words like "approximately", "around", or "in recent years" because the published figures evolve season by season.

Examples in context

Example 1. A QCE student profiles a Queensland junior netball goal shooter. The dominant components are power (for the rebound), balance (for the stable release inside the circle), coordination (hand-eye for shooting and ball control), agility (for getting open inside a small space), and aerobic capacity for the full quarter. Tests are the vertical jump for power, the stork stand and Y-balance for balance, the alternate-hand wall-toss for coordination, the 5-0-5 agility test, and the beep test for aerobic capacity. The student notes that reaction time and muscular strength matter less than for invasion sports because the position is confined to the circle.

Example 2. A student profiles a swimming sprinter (50 metre freestyle). The dominant components are anaerobic power (the entire race is around 22 to 28 seconds in elite competition), upper-body muscular strength and endurance, flexibility (especially shoulder and ankle), and reaction time at the start. Aerobic capacity matters less for the 50 free than it does for the 400 or 1500, where the dominant component shifts to aerobic capacity. The student uses a swim-specific tethered force test for power, 1RM bench pull and pull-up tests for strength, sit-and-reach for flexibility, and a starting-block reaction time measurement.

Example 3. A student profiles a U18 male rugby league forward. The dominant components are muscular strength (for the contact), anaerobic power (for repeat carries and tackles), aerobic capacity (for the volume of work), and agility (for evasion and defensive footwork). The student uses 1RM bench press and squat for strength, a vertical jump for power, the Yo-Yo Intermittent Recovery Test for aerobic capacity in a stop-start format, and a repeat-sprint test for anaerobic power. Reference data from NRL high-performance materials grounds the prioritisation.

Try this

Q1. List the five health-related components of fitness and one validated test for each. [5 marks]

• Cue. Aerobic capacity = beep test or Yo-Yo Intermittent Recovery Test. Muscular strength = 1RM bench press, squat, or deadlift. Muscular endurance = push-ups to fatigue or abdominal stage test. Flexibility = sit-and-reach. Body composition = skinfold caliper assessment by a trained tester.

Q2. For a chosen activity, prioritise three components of fitness and justify your prioritisation with reference to the activity's demands. [6 marks]

• Cue. Name the activity, then name the three components and justify each. For example, for an AFL midfielder: aerobic capacity (high running volume), anaerobic power (high-intensity bursts), and agility (change of direction). Justifications must tie to the activity, not be generic.

Q3. Explain why the Yo-Yo Intermittent Recovery Test is more specific to AFL than a continuous treadmill VO2 max test, even though both measure aerobic capacity. [3 marks]

• Cue. AFL is a stop-start sport with repeated high-intensity bursts and partial recovery. The Yo-Yo test uses a similar shuttle pattern with short recoveries, so it captures both aerobic capacity and the ability to recover between high-intensity efforts. A continuous treadmill test measures steady-state aerobic capacity but misses the recovery-between-efforts demand of the sport.