Sports Nutrition: Principles, Fueling, Recovery, and Hydration

Comprehensive vocabulary flashcards covering key definitions, metabolic principles, macronutrient protocols, hydration guidelines, and ergogenic aids from the Sports Nutrition lecture.

Physical activity

Movement resulting from the contraction of skeletal muscle.

Exercise

Physical activities that are usually planned and structured for a specific purpose.

Physical fitness

The ability to perform moderate to vigorous intensity activities without becoming excessively fatigued.

Genetic endowment

Inherited physical characteristics that can influence athletic performance.

Sports nutrition

The practice of applying nutrition principles and research findings to improving athletic performance and recovery following a training session.

Carbohydrate loading

The practice of manipulating physical activity and dietary carbohydrate intake to supercompensate and maximize muscle glycogen stores prior to endurance competition.

Sports gel

A concentrated, carbohydrate-rich gel formulated for athletes, particularly those engaged in prolonged endurance training and competition, providing easily digestible energy with minimal fluid.

Branched-chain amino acids (BCAAs)

Amino acids characterized by a unique branched molecular side chain that are preferentially taken up and utilized directly by muscle cells for energy.

Delayed onset muscle soreness (DOMS)

Muscular pain and discomfort that typically develops within $1$ to $2$ days following unaccustomed or intense exercise.

Whey protein

A nutrient-dense, rapidly digested protein fraction derived from milk during cheese manufacturing, constituting roughly $20\%$ of total milk protein and rich in essential amino acids and leucine.

Energy availability (EA)

The dietary energy intake remaining for physiological functions after accounting for exercise energy expenditure, normalized to fat-free mass ($\text{EA} = \frac{\text{Energy Intake} - \text{Exercise Energy Expenditure}}{\text{Fat-Free Mass}}$).

Relative Energy Deficiency in Sport (RED-S)

A syndrome of impaired physiological function—including metabolic rate, bone health, immunity, protein synthesis, and cardiovascular health—caused by chronic low energy availability in male and female athletes.

Dehydration

The dynamic physiological process of losing body water.

Hypohydration

The uncompensated, steady-state condition of body water deficit resulting from dehydration.

Heat cramps

Painful involuntary muscle spasms occurring during or after intense physical activity, designated as exercise-associated muscle cramps in National Athletic Trainers' Association (NATA) terminology.

Heat exhaustion

A heat-related condition marked by heavy sweating, weakness, dizziness, headache, or nausea following strenuous exertion, where core body temperature remains typically below $40.5^\circ\text{C}$.

Heatstroke

The most severe and life-threatening form of heat illness, characterized by profound central nervous system dysfunction and a core body temperature elevated above $40.5^\circ\text{C}$.

Hyponatremia

A potentially fatal electrolyte disturbance defined as a serum sodium concentration below $135\,\text{mmol/L}$, typically caused by excessive hypotonic fluid consumption exceeding sweat and urinary losses.

Total energy expenditure (TEE)

The overall daily energy expenditure of an individual, represented by the sum of basal metabolic rate ($\text{BMR}$), thermic effect of food ($\text{TEF}$), and thermic effect of activity ($\text{TER}$).

Thermic effect of activity (TER)

The component of total daily energy expenditure comprising planned exercise expenditure, spontaneous physical activity, and non-exercise activity thermogenesis ($\text{NEAT}$).

"Train low"

The deliberate practice of training with restricted endogenous or exogenous carbohydrate availability to promote metabolic cellular adaptations, despite impairing exercise intensity and duration.

"Hitting the wall"

A state of severe exhaustion, decreased work output, and heavy fatigue experienced during endurance events due to complete depletion of endogenous liver and muscle glycogen reserves.

Speedy refueling

An aggressive post-exercise recovery strategy specifying an intake of $1$ to $1.2\,\text{g/kg/hour}$ of carbohydrate over the first $4$ hours when subsequent training occurs within an $8$-hour recovery window.

Euhydration

A state of normal, optimal body water content, typically indicated by a first-morning urine specific gravity below $1.020$ or a urine osmolality below $700\,\text{mOsmol/kg}$.

Foot-strike hemolysis

The physical trauma and mechanical destruction of erythrocytes caused by repetitive impact of the feet on hard surfaces during running, contributing to elevated iron turnover.

Creatine

An evidence-based dietary supplement that enhances intramuscular phosphocreatine stores to improve performance during repeated bouts of high-intensity exercise with brief recovery intervals.

Caffeine (ergogenic aid)

A central nervous system stimulant that enhances athletic endurance and work output primarily by reducing the athlete's perception of effort and fatigue.

Sodium bicarbonate

An extracellular buffering supplement used to neutralize hydrogen ion accumulation and acid-base disturbances during high-intensity exercise lasting $1$ to $7$ minutes.

Beta-alanine

An amino acid supplement that increases muscle carnosine synthesis to enhance intracellular buffering capacity during high-intensity exercise lasting $60$ to $240$ seconds.

Dietary nitrate

A nutritional ergogenic supplement, commonly found in beetroot juice, that improves exercise economy and tolerance by promoting nitric oxide-mediated vasodilation and mitochondrial efficiency.