AQA · A-Level · Physical Education
Course version: 7582 · Version from Sept 2016
Drugs in sport: Erythropoietin (EPO).
Erythropoietin (EPO) is a hormone that stimulates red blood cell production in bone marrow.
Checked against the AQA 7582 specification (opens in a new tab) on .
- Point 3 of 10
- 4 key terms
Study notes
From the checked teaching notes for this specification point.
The idea
Erythropoietin (EPO) is a hormone that stimulates red blood cell production in bone marrow. More red blood cells raise haemoglobin concentration, so the blood carries more oxygen to working muscles. This can delay fatigue and improve endurance performance. However, EPO also raises blood viscosity, increasing the risk of blood clots, stroke and heart attack. It can suppress natural EPO production, and athletes may use it alongside blood doping. The performer's performance may improve in endurance events, but the health risk is serious and the effect is not unlimited. EPO is banned in sport.
What earns the marks
- EPO stimulates red blood cell production in bone marrow, increasing haemoglobin concentration and oxygen-carrying capacity.
- The physiological benefit is delayed fatigue and improved endurance performance because more oxygen reaches working muscles.
- EPO raises blood viscosity, increasing the risk of blood clots, stroke and heart attack.
- EPO can suppress natural EPO production, and it is banned in sport.
- The performance effect is specific to endurance events and is not unlimited; health risks can outweigh benefits.
Common mistakes and how to put them right
Misunderstanding: EPO directly increases muscle strength.
Put it right: EPO increases oxygen-carrying capacity, so its main performance benefit is in endurance, not maximal strength.
Misunderstanding: EPO is safe because it is a natural hormone.
Put it right: Raising red blood cell count increases blood viscosity and the risk of clots, stroke and heart attack.
Misunderstanding: EPO works immediately.
Put it right: It stimulates red blood cell production over time, so the effect develops gradually.
Misunderstanding: EPO improves performance in all sports equally.
Put it right: The benefit is greatest in endurance events where oxygen delivery limits performance.
Exam tips
- State the mechanism first: EPO stimulates red blood cell production, which raises haemoglobin and oxygen transport.
- Link the mechanism to a specific endurance performance outcome, such as delayed fatigue in a long-distance event.
- Include at least one serious health risk, such as increased blood viscosity leading to clots, stroke or heart attack.
Try the lesson
The start of the Drugs in sport: Erythropoietin (EPO). lesson, made from checked teaching notes for this specification point.
Have a go first
What is the main physiological effect of erythropoietin (EPO) that makes it attractive to endurance athletes?
Listen
Erythropoietin (EPO) is a hormone that stimulates red blood cell production in bone marrow. More red blood cells raise haemoglobin concentration, so the blood carries more oxygen to working muscles. This can delay fatigue and improve endurance performance. However, EPO also raises blood viscosity, increasing the risk of blood clots, stroke and heart attack. It can suppress natural EPO production, and athletes may use it alongside blood doping. The performer's performance may improve in endurance events, but the health risk is serious and the effect is not unlimited. EPO is banned in sport. A strong answer earns marks for these points. EPO stimulates red blood cell production in bone marrow, increasing haemoglobin concentration and oxygen-carrying capacity. The physiological benefit is delayed fatigue and improved endurance performance because more oxygen reaches working muscles. EPO raises blood viscosity, increasing the risk of blood clots, stroke and heart attack. EPO can suppress natural EPO production, and it is banned in sport. A common slip: Misunderstanding: EPO directly increases muscle strength. Instead, EPO increases oxygen-carrying capacity, so its main performance benefit is in endurance, not maximal strength. Exam tip: State the mechanism first: EPO stimulates red blood cell production, which raises haemoglobin and oxygen transport.
Key words
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Oxygen transport and endurance performance
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Hormonal control of red blood cell production
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Health risks of increased blood viscosity
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Banned substances in sport
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See every definition
- Oxygen transport and endurance performance
- More red blood cells raise haemoglobin concentration, so the blood carries more oxygen to working muscles, which can delay fatigue and improve endurance performance.
- Hormonal control of red blood cell production
- A hormone that stimulates red blood cell production in bone marrow, and it can suppress natural EPO production.
- Health risks of increased blood viscosity
- Raising blood viscosity increases the risk of blood clots, stroke and heart attack, so the health risk is serious.
- Banned substances in sport
- EPO is banned in sport, and athletes may use it alongside blood doping.
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