IB Sports, exercise and health science A.2 Hydration and Nutrition Key Definitions

A high-energy molecule that stores and provides energy for cellular processes, including muscle contraction and metabolism.

Adenosine triphosphate (ATP) is the primary chemical energy currency of the cell. Hydrolysis of ATP releases the energy used for muscle contraction, ion transport, and most other energy-requiring processes.

Body fat that stores energy and fat-soluble vitamins.

A type of exercise that improves the body's ability to sustain prolonged physical activity by enhancing cardiovascular and muscular efficiency.

A hormone that regulates sodium and potassium levels in the body, influencing water retention and blood pressure.

The metabolic process that builds complex molecules from simpler ones, using energy (e.g., muscle protein synthesis).

A hormone that increases water reabsorption in the kidneys to prevent dehydration.

A condition in which the immune system mistakenly attacks the body’s own cells

A diet that provides all essential nutrients (carbohydrate, lipid, protein, water, vitamins, minerals) in the right amounts to maintain health and prevent both nutrient deficiency and nutrient excess.

The amount of energy required by the body to maintain basic physiological functions at rest.

The process of releasing energy from fatty acids inside the mitochondria. Fatty acid chains are gradually broken down into acetyl CoA molecules, each cycle shortening the chain by two carbons and yielding energy.

The primary form of carbon dioxide transport in the blood, formed when CO₂ combines with water.

Essential amino acids (leucine, isoleucine, valine) that support muscle protein synthesis and recovery, influenced by gut microbiome activity.

Carbohydrate loading is a dietary strategy aimed at increasing muscle glycogen stores before endurance events.

The volume of blood the heart pumps per minute.

Cardiovascular drift is the gradual increase in heart rate (HR) observed during prolonged submaximal exercise, typically when the body is exposed to heat or thermoneutral conditions.

The metabolic process that breaks down complex molecules to release energy (e.g., breaking down glucose to produce ATP).

The controlled release of energy in the form of ATP from organic molecules inside cells. It takes place mainly in the mitochondria for aerobic respiration and in the cytosol for anaerobic glycolysis.

The process in which lactate is transported to the liver and converted back into glucose via gluconeogenesis.

A supplement that enhances ATP replenishment, muscle hydration, and recovery from high-intensity exercise.

A molecule stored in muscles that rapidly regenerates ATP from ADP during short, high-intensity activities.

The highest power output an individual can sustain over time without a rapid rise in blood lactate levels, closely related to endurance capacity.

The dynamic process of losing body water. It is the action that produces a state of hypohydration.

Substances that increase urine production, leading to fluid loss (e.g., caffeine, alcohol, certain medications).