Energy Systems Adaptations Worksheet

Name:

Date:

📚 Part 1: Multiple Choice & Matching

1. Which energy system primarily powers a single maximal sprint lasting 6–8 seconds?

Aerobic (oxidative) system

ATP-PC (phosphocreatine) system

Anaerobic glycolysis (lactic) system

2. A key long-term adaptation to aerobic endurance training is:

Increased phosphocreatine stores in muscles

Increased mitochondrial density and capillary density

Increased glycolytic enzyme activity only

3. Check all adaptations that are typical of repeated high-intensity interval training (HIIT) targeting the anaerobic glycolysis system:

Increased buffering capacity (resistance to acidosis)

Increased mitochondrial density to the same extent as continuous endurance training

Increased glycolytic enzyme activity

Improved lactate tolerance and removal

4. Match each energy-system adaptation (left) with the correct description (right). Draw a line between the matching items.

A. Increased myoglobin

B. Increased creatine kinase activity

C. Increased lactate threshold

D. Increased capillary density

1. Supports faster ATP resynthesis from phosphocreatine

2. Improves oxygen delivery and exchange in muscles

3. Helps transport oxygen inside muscle fibres for aerobic metabolism

4. Allows higher intensity exercise before fatigue from lactic acid

✏️ Part 2: Short Answer & Applied Tasks

5. Briefly explain one cellular adaptation in muscle that improves aerobic energy production. Include the benefit to performance. (2–3 sentences)

6. Coaches want to develop a rugby forward's ATP-PC system. Suggest one specific training drill, state the work:rest ratio, and explain why this develops ATP-PC adaptations. ____

7. Calculate: A hockey player performs repeated 30-second high-intensity efforts relying largely on anaerobic glycolysis. If each 30 s effort produces 40 mmol·L−1 of blood lactate and recovery brings lactate down by 25% each 3 minutes, what approximate lactate level remains after one 3-minute recovery? Show your working.

8. Describe two cardiovascular adaptations from long-term aerobic training and give one measurable test or metric to assess each adaptation (e.g. VO2max, resting heart rate).

9. Practical planning: For an athlete aiming to increase aerobic capacity, list the recommended frequency (times per week), typical session duration, and intensity zone (use % of maximal heart rate or perceived exertion). Keep it concise.

10. Sketch (labelled) a simple diagram showing where the three energy systems dominate during an 800 m run (start, middle, finish). Indicate approximate time ranges and primary adaptations for each phase.