Theme A explores how the body's physiological systems work together to support health, physical activity, and sporting performance . You will investigate communication between body systems, the maintenance of stable internal conditions, transportation of gases and nutrients, nutrition and hydration, energy production, training responses, and the health effects of physical activity.

This topic examines how different systems within the human body communicate and coordinate their functions.

This topic explores how food, water, and energy availability influence both health and performance .

Water and Electrolyte Balance

You will study why maintaining appropriate levels of water and electrolytes is essential for normal physiological function. Possible areas include:

• Fluid intake and loss
• Sweat and evaporation
• Electrolyte regulation
• Dehydration
• Hypernatremia
• Hyponatremia
• Body mass and urine measurements of hydration
• Cardiovascular drift during prolonged exercise

You will also examine how the hypothalamus, pituitary gland, and kidneys help regulate water and electrolyte balance.

The final topic in Theme A investigates how the body responds and adapts to training and physical activity.