IB SEHS: Exercise Responses Explained for Exam Marks

Identify the response (be specific)

Your first line should signal clarity. In IB SEHS, precision helps examiners award marks quickly.

Good starters:

• “Heart rate increases with exercise intensity to…”

• “Minute ventilation increases because…”

• “Stroke volume increases during submaximal exercise due to…”

Avoid foggy openers like “the body changes” or “the system responds.”

For terminology support, RevisionDojo’s SEHS resources hub and Exercise Physiology notes are a solid reset.

Explain why it happens (show the mechanism)

This is where IB SEHS answers separate understanding from memorisation. Causes usually connect to:

• Higher oxygen demand in working muscles

• Increased carbon dioxide production

• Increased energy requirement (ATP turnover)

• Need to maintain blood pH and homeostasis

Example (cardiovascular): heart rate rises to increase cardiac output (CO = HR × SV), delivering more oxygen and removing metabolites.

Example (respiratory): breathing rate and tidal volume increase to raise ventilation, helping meet oxygen demand and expel CO2.

If you need quick clarity on the systems behind those explanations, use A.1.2 Maintaining homeostasis notes and Respiratory system and gas exchange notes.

Link to performance (the “so what” mark)

Many students stop one sentence early. In IB SEHS, that last link often equals the difference between mid marks and top marks.

Performance links can include:

• Improved oxygen delivery and aerobic metabolism

• Faster CO2 removal to support pH balance

• Delayed fatigue by meeting energy demand efficiently

• Better ability to sustain a given exercise intensity

To practise this in exam style, use the A.1.3 Transport Questionbank and the A.3 Response Questionbank. RevisionDojo’s AI Chat can also help you tighten wording when your explanation is correct but too vague.

Common IB SEHS mistakes that cap your score

• Listing without explaining: “HR increases, SV increases” isn’t a mechanism.

• Mixing acute and chronic: exercise responses happen during a bout; adaptations happen after weeks of training.

• No intensity link: many prompts want “as intensity increases,” not a generic statement.

This is where RevisionDojo’s loop works well: Study Notes for clarity, Flashcards for key terms, then Questionbank to repeat the structure until it becomes automatic.

Final takeaway: write like an IB SEHS examiner is reading fast

In IB SEHS, exercise responses are predictable, but marks aren’t automatic. The exam rewards students who write with intention: identify the change, explain the physiology, link it to performance. If you want that structure to feel natural under pressure, RevisionDojo is built for the full loop: Study Notes, Flashcards, Questionbank, AI Chat, Grading tools, Predicted Papers, Mock Exams, a Coursework Library, and Tutors.

Make your next practice set a simple challenge: every answer must include the full IB SEHS chain--what changes, why it changes, and why it matters.

IB SEHS goal setting in sport made simple: goal types, SMART targets, common mistakes, and exam-ready tips using RevisionDojo practice tools.