Drugs in sport: Physiological adaptations.

The idea

Physiological adaptations are the body's structural and functional changes in response to training or drug use. In the context of drugs in sport, anabolic steroids increase muscle protein synthesis, leading to muscle hypertrophy and increased strength. EPO stimulates red blood cell production, raising haemoglobin and oxygen-carrying capacity, which improves aerobic endurance. Human growth hormone increases muscle mass and bone density. Beta-blockers reduce heart rate and tremor, benefiting precision sports. Diuretics promote fluid loss, aiding weight loss but risking dehydration. Blood doping increases red blood cell count. Each adaptation affects performance differently and carries health risks. Understanding these adaptations helps explain why performers use drugs and how they enhance performance.

What earns the marks

• Anabolic steroids increase muscle protein synthesis, causing muscle hypertrophy and increased strength.
• EPO increases red blood cell production, raising haemoglobin and oxygen-carrying capacity for aerobic endurance.
• Human growth hormone increases muscle mass and bone density.
• Beta-blockers reduce heart rate and tremor, improving precision and reducing anxiety.
• Diuretics increase urine production, causing fluid loss and weight loss.
• Blood doping increases red blood cell count, improving oxygen delivery to muscles.
• Each adaptation carries health risks such as cardiovascular strain, liver damage or dehydration.

Common mistakes and how to put them right

• Confusing EPO with anabolic steroids.

  Put it right: EPO increases red blood cell production, while anabolic steroids increase muscle protein synthesis.

• Thinking beta-blockers increase heart rate.

  Put it right: Beta-blockers decrease heart rate and reduce tremor.

• Assuming diuretics improve performance by increasing hydration.

  Put it right: Diuretics cause fluid loss and can impair performance through dehydration.

• Believing all drugs have the same physiological effect.

  Put it right: Each drug class has a specific adaptation, such as muscle growth, oxygen transport or tremor reduction.

Exam tips

• Link each drug to its specific physiological adaptation and the performance benefit it provides.
• Remember that adaptations can be harmful; mention health risks where relevant.
• Use accurate terminology such as haemoglobin, oxygen-carrying capacity, muscle hypertrophy and protein synthesis.
• For MCQ, eliminate options that confuse the effects of different drugs.