Creatine, sodium bicarbonate, caffeine, Glycogen loading.

The idea

This topic covers four ergogenic aids: creatine, sodium bicarbonate, caffeine and glycogen loading. Creatine increases phosphocreatine stores, aiding short, explosive efforts such as sprint starts or repeated jumps. Sodium bicarbonate acts as a buffer, neutralising hydrogen ions that lower muscle pH during high-intensity work, so it can delay fatigue in events lasting roughly one to several minutes. Caffeine is a stimulant that can reduce perceived exertion and increase alertness, benefiting endurance and some team sports. Glycogen loading raises muscle glycogen before endurance events by tapering training while increasing carbohydrate intake, extending time to exhaustion. Each aid has evidence-based benefits, side effects and legal or ethical considerations, and effects vary with dose, timing, individual response and event demands.

What earns the marks

• Creatine increases phosphocreatine stores, supporting ATP resynthesis during short, explosive efforts such as sprinting or jumping.
• Sodium bicarbonate buffers hydrogen ions, reducing the acidity that contributes to fatigue in high-intensity exercise lasting about one to several minutes.
• Caffeine is a stimulant that can lower perceived exertion and improve alertness, benefiting endurance performance and some team-sport activities.
• Glycogen loading raises muscle glycogen stores before endurance events by tapering training and increasing carbohydrate intake, delaying fatigue.
• Each aid has side effects and legal or ethical considerations, and effectiveness depends on dose, timing, individual response and the demands of the event.

Common mistakes and how to put them right

• Misunderstanding: creatine directly provides energy for endurance events.

  Put it right: Creatine increases phosphocreatine stores, which support short, explosive efforts, not prolonged aerobic performance.

• Misunderstanding: sodium bicarbonate works by increasing oxygen delivery.

  Put it right: It acts as a buffer, neutralising hydrogen ions that lower muscle pH during high-intensity work.

• Misunderstanding: caffeine is banned in all sport.

  Put it right: Caffeine is permitted by WADA at all times, though it remains a stimulant with side effects and individual variability.

• Misunderstanding: glycogen loading means eating more protein.

  Put it right: Glycogen loading involves tapering training while increasing carbohydrate intake to raise muscle glycogen stores.

Exam tips

• Link each aid to the specific energy system or fatigue mechanism it targets, such as phosphocreatine for creatine or buffering for sodium bicarbonate.
• Use precise terms like phosphocreatine, hydrogen ions, perceived exertion and muscle glycogen rather than vague phrases like 'gives energy'.
• When evaluating, consider dose, timing, individual response, side effects and the legal or ethical context of each aid.