Exercise Physiology: Nutrition, Training Adaptations, and Altitude

Comprehensive practice flashcards detailing sports nutrition, hydration, detraining, overtraining syndrome, and high-altitude physiology from lecture notes.

Water Balance at Rest

The physiological state where water intake equals water output, with daily intake averaging $33\,\text{ml/kg}$ per day.

Avenues of Water Loss

The four physiological pathways through which the body eliminates fluids: evaporation from the skin, evaporation from the respiratory tract, excretion from the kidneys, and excretion from the large intestines.

Exercise Water Loss Rate

Fluid loss accelerated by sweating during physical activity, reaching rates of $2\text{--}3\,\text{L/hour}$, which impairs performance by reducing blood pressure and muscle blood flow.

Sports Drink Formulation

A fluid replacement solution containing $6\text{--}8\%$ sugar and sodium to facilitate fluid intake, improve performance, and reduce dehydration risk in endurance and burst activities.

Dehydration Symptoms ($1\text{--}2\%$ Loss)

The initial symptoms of body water deficit, characterized by thirst, fatigue, and weakness.

Dehydration Symptoms ($3\text{--}4\%$ Loss)

The progressive signs of fluid loss manifested as a decline in athletic performance, dry mouth, and decreased urine output.

Dehydration Symptoms ($5\text{--}6\%$ Loss)

Moderate-level dehydration symptoms marked by a decrease in concentration, headache, and increased breathing rate.

Dehydration Symptoms ($7\text{--}10\%$ Loss)

Severe dehydration symptoms presenting as dizziness, muscle spasms or cramps, and loss of balance.

Iron

A micromineral present at $35\text{--}50\,\text{mg/kg}$ of body weight that is crucial for oxygen transport and the synthesis of hemoglobin and myoglobin.

Electrolytes (Sodium, Potassium, and Chloride)

Minerals that establish the separation of electrical charge across neuron and muscle cell membranes, maintain body water balance and distribution, and support normal osmotic equilibrium, $\text{pH}$, and cardiac rhythm.

Post-Exercise Rehydration Rate

The recommended practice of consuming $20\text{--}24\,\text{fl oz}$ of fluid for every $1\,\text{lb}$ of body weight lost during physical exercise.

Macrominerals vs. Microminerals

A mineral classification based on required intake: macrominerals are needed in daily amounts $> 100\,\text{mg}$, whereas microminerals are needed in amounts $\le 100\,\text{mg}$.

Calcium

The body's most abundant mineral, constituting $40\%$ of bone mineral, found in milk, sardines, tofu, and leafy greens.

Phosphorus

A dietary mineral linked to calcium in calcium phosphate that gives structural strength to bones and helps maintain blood $\text{pH}$.

Vitamin E

A fat-soluble antioxidant residing in muscle and fat that prevents the oxidation of vitamins A and C and neutralizes free radicals.

Fat-Soluble Vitamins

Vitamins A, D, E, and K, which are absorbed from the digestive tract bound to lipids.

Water-Soluble Vitamins

The vitamin class comprising the B complex vitamins and Vitamin C.

Vitamin C

A water-soluble nutrient essential for collagen formation, amino acid metabolism, iron absorption, and the synthesis of epinephrine, norepinephrine, and anti-inflammatory corticoids.

Protein Intake Upper Limit

An intake exceeding $1.7\,\text{g/kg}$ per day, which provides no athletic performance advantage and may cause dehydration and/or kidney damage.

Glycemic Index

An indicator that quantifies the blood glucose response to the ingestion of a particular food.

Dietary Fat Intake Guidelines

A recommended intake of $0.5\text{--}1.0\,\text{g/kg}$ of body weight per day that supplies approximately $70\%$ of energy at rest and should never drop below $15\%$ of daily calories.

Protein Intake Recommendations

Daily intake standards set at an RDA of $0.8\text{--}1.0\,\text{g/kg/day}$, with endurance athletes requiring $1.2\text{--}1.4\,\text{g/kg/day}$ and strength training athletes requiring $1.6\text{--}1.7\,\text{g/kg/day}$.

Balanced Athletic Macronutrient Distribution

A dietary balance consisting of $55\text{--}60\%$ carbohydrate, no more than $35\%$ fat (with less than $10\%$ saturated fat), and $10\text{--}15\%$ protein.

Precompetition Meal

A pre-event meal containing $200\text{--}500\,\text{kcals}$ of easily digestible carbohydrates with no sugar, accompanied by $400\text{--}600\,\text{ml}$ of fluids, eaten at least $2\,\text{hours}$ before competition.

Preexercise Glycogen Loading

A dietary strategy involving $3\,\text{days}$ of consuming a $10\,\text{g/kg/day}$ carbohydrate diet to elevate and maintain high muscle glycogen stores for $3\text{--}5\,\text{days}$.

Sequence of Detraining Losses

The physiological order in which capacities decline following cessation of training: cardiorespiratory endurance is lost first, flexibility second, and strength and power third.

Detraining

The partial or complete loss of training-induced adaptations resulting from the cessation of training or a substantial decrease in training load.

Tapering

A systematic reduction in training intensity and volume lasting $4\text{--}28\,\text{days}$ that restores energy reserves, increases strength, and improves performance by $3\%$ without decreasing $\text{VO}_2\,\text{max}$.

Bed Rest Adaptations (20 Days)

Physiological changes resulting from prolonged inactivity, including increased submaximal heart rate, a $25\%$ reduction in stroke volume, a $25\%$ drop in maximal cardiac output, a $27\%$ reduction in $\text{VO}_2\,\text{max}$, and decreased plasma volume.

Detraining Prevention Threshold

The maintenance guideline requiring at least $3$ training sessions per week at a minimum intensity of $70\%\,\text{VO}_2\,\text{max}$ for cardiovascular fitness, and $1\text{--}2\,\text{days}$ of resistance exercise for strength.

Undertraining

The low level of training stimulus that an athlete performs during the off-season or active rest.

Acute Overload

Systematically stressing the body during training to stimulate physiological adaptation and improve performance.

Overreaching

A systematic approach to overstressing the body with heavy training loads and minimal recovery, causing short-term decrements the next day followed by rebound increases in physiological performance.

Overtraining Syndrome

An unexplained, chronic decline in athletic performance accompanied by physiological maladaptations that cannot be resolved by short-term training reductions or nutritional alterations.

Sympathetic Overtraining

A form of overtraining linked to anaerobic exertion characterized by increased resting heart rate, increased resting blood pressure, appetite loss, weight loss, sleep disturbances, emotional instability, and elevated resting metabolic rate.

Parasympathetic Overtraining

A form of overtraining linked to aerobic exertion characterized by early onset fatigue, decreased resting heart rate, abnormally rapid heart rate recovery post-exercise, and decreased resting blood pressure.

Fixed-Pace Exercise Bout

The primary field detection method used by coaches and athletes to identify early overtraining by monitoring for higher-than-normal heart rate responses.

Hypoxic High-Altitude Environment

Environmental conditions found above $1500\,\text{m}$ above sea level, characterized by reduced barometric pressure, decreased partial pressure of oxygen ($\text{P}_{\text{O}_2}$ dropping from $159\,\text{mmHg}$ at sea level to $110\,\text{mmHg}$ at $10000\,\text{ft}$), drier air, and increased solar radiation.

Respiratory Alkalosis at Altitude

The excessive expiration of carbon dioxide ($\text{CO}_2$) triggered by the acute increase in ventilation rate and depth as peripheral chemoreceptors sense hypoxic conditions.

Altitude Acclimatization Timeline

A physiological adjustment requiring $2\,\text{weeks}$ for moderate altitudes plus $1\,\text{week}$ per each additional $1000\,\text{ft}$, with all acquired benefits dissipating within $2\text{--}3\,\text{weeks}$ upon return to sea level.

Hematological Acclimation to Altitude

Blood changes initiated by erythropoietin release from the kidneys, resulting in increased red blood cell production, elevated hemoglobin concentration, expanded blood volume, and increased oxygen-carrying capacity.

Live-High, Train-Low

The evidence-based altitude strategy wherein athletes reside at moderate-to-high altitudes to stimulate physiological acclimatization while training at low altitudes to maintain high workout intensity.