Fiducia TogetherEnergy systems and the body
How the body fuels exercise, and what happens to it during and after.
Please note: This page explains a word or a process in education. It is general information about the system, the law and the guidance in England — not advice about your child, your school or your exam. If a decision is going against you, get advice from one of the free services we link to before you agree to anything or miss a deadline. If you are revising, check your own exam board's specification: boards word things differently and yours is the one that marks you.
What it is
Aerobic exercise uses oxygen and suits long duration and lower intensity. Anaerobic exercise works without sufficient oxygen, suits short high-intensity effort, and produces lactic acid.
Where it applies
GCSE PE and BTEC sport.
How it works
Short-term effects of exercise include raised heart rate, breathing rate and temperature. Long-term adaptations include a lower resting heart rate, increased stroke volume, stronger respiratory muscles and greater muscle hypertrophy.
EPOC — the oxygen debt repaid after exercise — explains continued heavy breathing after stopping.
How to use it in your work
Distinguish short-term effects from long-term adaptations. Questions ask for one and students give the other.
Use the correct terms: hypertrophy, stroke volume, cardiac output, tidal volume.
Link the system to the activity: a marathon is aerobic, a 100m sprint anaerobic, a football match both.
Where to get help
Your teacher and your board's specification — these qualifications vary more between boards than the traditional GCSEs do, and much of the grade is coursework marked against stated criteria.
Revise this with a song
These are ours. We write revision songs because a lot of people remember a tune when they cannot remember a page, and because revising out loud in the kitchen beats staring at a highlighter.
- The PE Song The GCSE PE topics, set to music.
Where to read more
Last reviewed 2026-08-28 by Fiducia Together · Next review due 2027-08-28
Please note: This page explains a word or a process in education. It is general information about the system, the law and the guidance in England — not advice about your child, your school or your exam. If a decision is going against you, get advice from one of the free services we link to before you agree to anything or miss a deadline. If you are revising, check your own exam board's specification: boards word things differently and yours is the one that marks you.