Energy systems (ATP-PC, anaerobic glycolysis, aerobic), fitness components, and the integration of energy and fitness principles into training programs for a chosen physical activity

What this dot point is asking

QCAA wants you to integrate the three energy systems, the fitness components, and the training principles into a coherent training program for a chosen physical activity. The marks come from matching the energy system and fitness demands of a specific activity to the right training methods, and from justifying choices with named training principles, rather than describing the systems in isolation.

The answer

The three energy systems

All three systems run at the same time; their relative contribution shifts with intensity and duration.

• ATP-PC system. Fuel is creatine phosphate. It powers very short, explosive efforts of roughly 10 to 12 seconds (a sprint, a maximal jump). It resynthesises ATP very rapidly but has a small capacity; it recovers about half its capacity in around 30 seconds and fully in a few minutes.
• Anaerobic glycolysis system. Fuel is muscle glycogen broken down without oxygen. It dominates high-intensity efforts from about 30 seconds to roughly 3 minutes (a 400 m run, a 100 m swim). It is faster than the aerobic system but inefficient, and fatigue is associated with the build-up of hydrogen ions and falling muscle pH (acidosis).
• Aerobic system. Fuel is carbohydrate and fat fully oxidised with oxygen. It dominates sustained efforts beyond about 3 minutes (a distance run, a soccer or AFL match). It produces a large amount of ATP per fuel molecule but slowly; fatigue comes from glycogen depletion, dehydration, and heat over long durations.

Fitness components

• Health-related components. Aerobic capacity (cardiorespiratory endurance), muscular strength, muscular endurance, flexibility, and body composition.
• Skill-related components. Speed, power (force times speed), agility, coordination, balance, and reaction time.

Different activities prioritise different components: a marathon is aerobic-capacity dominant, a 100 m sprinter is power and speed dominant, soccer demands aerobic capacity plus speed, agility, and power, and powerlifting is strength dominant.

Training principles

• Specificity. Train the muscles, energy systems, movement patterns, and speeds the sport demands.
• Progressive overload. Gradually and systematically increase the training stimulus over time.
• Reversibility. Adaptations are lost when training stops or reduces.
• Variety. Different sessions and modes to prevent staleness.
• Individuality. Programs reflect the individual athlete's response.
• Periodisation. Structured planning across phases (base, specific, competitive, transition).
• FITT. Frequency, Intensity, Time, and Type as the prescription framework.

Training methods

Methods are matched to the targeted energy system and fitness component.

• Aerobic. Continuous training (sustained moderate intensity), fartlek (continuous with intensity changes), aerobic intervals, and circuit training.
• Anaerobic. Short intervals (about 10 to 30 seconds with full recovery) for the ATP-PC system; long intervals (about 30 to 120 seconds with limited recovery) for the glycolytic system.
• Strength and power. Resistance training and plyometric training (the stretch-shortening cycle for power).
• Flexibility. Static stretching, dynamic stretching, and PNF (contract-relax).

Integration into a training program

A QCE Unit 4 program for a soccer player integrates all three energy systems (aerobic via continuous runs and intervals; glycolytic via long intervals and game work; ATP-PC via sprints and skills), multiple fitness components (aerobic capacity, speed, agility, power, muscular endurance), and all the principles (specificity to soccer, progressive overload across a pre-season block, FITT, variety, and periodisation). The key is that the elements work together rather than in isolation.

Examples in context

Example 1. A QCE student designs a pre-season block for a rugby league player. The activity is intermittent and high-intensity, so the program develops the ATP-PC system with short maximal sprints and full recovery, the glycolytic system with repeat-sprint sets at limited recovery, and the aerobic base with continuous and interval running to support repeated efforts and recovery between bursts. Progressive overload is applied by increasing the number of sprint repeats each week, and specificity is met by using game-realistic distances and change-of-direction patterns.

Example 2. A 1500 m runner's program is aerobic-capacity dominant but still needs the glycolytic system for the finishing kick. The program uses continuous runs and aerobic intervals for the base, then adds long anaerobic intervals near the competition phase to develop tolerance to acidosis for the final lap. Periodisation moves the emphasis from base aerobic work to event-specific speed across the season, with a transition phase to allow recovery.

Try this

Q1. Identify the dominant energy system for a 100 m sprint and explain why the ATP-PC system suits this event. [3 marks]

• Cue. ATP-PC system; it resynthesises ATP very rapidly from creatine phosphate to power an explosive, near-maximal effort lasting roughly 10 seconds, before its small capacity is exhausted.

Q2. Explain the training principle of specificity and apply it to the design of an aerobic training session for a distance cyclist. [4 marks]

• Cue. Specificity = training the energy systems, muscles, movement patterns, and intensities the sport demands; for a distance cyclist this means continuous and interval cycling at race-relevant intensities and cadence, not running or general aerobic work.

Q3. A soccer player needs to develop repeat-sprint ability. Recommend a training method, identify the energy systems it develops, and justify the choice with two training principles. [6 marks]

• Cue. Repeat-sprint or long-anaerobic interval training; develops the ATP-PC and glycolytic systems (with an aerobic recovery component); justified by specificity (matches soccer's repeated high-intensity bursts) and progressive overload (increase repeats or reduce recovery over the block).