Physiology - Exercise Physiology

Prolonged life

Main benefit of maintaining fitness through exercise

100%

Metabolism increase during a high fever

2000%

Metabolism increase during a marathon

Physiologic stress

Form of stress that exercise represents

Limits of physiological mechanisms under stress

Main focus of exercise physiology

False

T/F: Exercise has no upper limit for safe performance.

True

T/F: High-intensity exercise can be fatal under extreme conditions.

False

T/F: Exercise always improves metabolism regardless of duration.

True

T/F: A marathon increases metabolism more than a fever.

True

T/F: Exercise is considered a stressor to the body.

Testosterone

Hormone responsible for greater muscle mass in males

Women have ⅔–¾ the strength of men

Typical muscle strength difference between sexes

3-4 kg/cm2

Muscle strength per unit area (kg/cm²)

More muscle mass, not greater contractile force

Anatomical reason for greater male muscle strength

Swimming across the English Channel

Event where females outperform males due to buoyancy

True

T/F: Males and females have equal maximal force per muscle unit.

False

T/F: Testosterone increases fat deposition.

False

T/F: Estrogen enhances upper body strength.

False

T/F: Most muscle strength difference is due to contractile force.

True

T/F: Men have more muscle mass due to hormonal effects.

Strength

Maximal contractile force of a muscle

Power

Work done per unit time

Endurance

Duration muscles can sustain activity

~40% more

Holding strength compared to contractile strength

High-carbohydrate diet

Diet that provides the longest endurance

False

T/F: Power is the same as strength.

True

T/F: Endurance depends heavily on glycogen stores.

False

T/F: Holding strength is always less than contractile strength.

False

T/F: A high-fat diet improves endurance better than a mixed diet.

True

T/F: Quadriceps muscle strength can reach up to 840 kg in holding strength.

ATP

Immediate energy source for muscle contraction

Phosphagen system

System with the highest ATP generation speed

Aerobic system

System that sustains long-term energy

Lactic acid

Main energy product of glycogen breakdown without oxygen

~8-10 seconds of activity

ATP yield of Phosphocreatine-Creatine system

False

T/F: Glycogen-lactic acid system requires oxygen.

True

T/F: Aerobic system produces ATP slower than anaerobic systems.

True

T/F: Muscle contains enough ATP to last ~3 seconds.

True

T/F: The aerobic system can regenerate phosphocreatine.

False

T/F: Anaerobic systems are optimal for long endurance sports.

Oxygen debt

Term for extra oxygen consumed after exercise

Alactacid and lactic acid debts

Two components of oxygen debt

Liver

Primary organ for converting lactic acid to glucose

~2 days

Time to replenish glycogen on high-carb diet

Provides ~30-40% of energy

Effect of glucose drinks in marathon

False

T/F: Muscle glycogen can be restored within hours post-exercise.

True

T/F: Alactacid debt restores phosphagen system.

False

T/F: Lactic acid is completely excreted in urine.

True

T/F: Glucose and fat are both used during recovery.

True

T/F: No food intake delays glycogen recovery.

100-110 L/min

Maximum pulmonary ventilation in exercise

Cardiovascular system

Main limiting factor in oxygen delivery

40% higher in athletes

Cardiac output of trained athletes vs non-athletes

Low HR, High SV

Change in heart rate and stroke volume in athletes

Cilia paralysis and bronchiole constriction

Smoking effect on lungs

False

T/F: Trained athletes have higher resting cardiac output.

False

T/F: Respiratory system is often the limiting factor in maximal exercise.

True

T/F: Cardiac hypertrophy occurs with endurance training.

False

T/F: Smoking improves respiratory function in athletes.

True

T/F: Blood oxygen levels remain normal even during maximal exercise.

Heat

Main byproduct of metabolism during exercise

41–42°C

Temperature range in heat stroke

~20-25%

Efficiency of energy converted into work

Ice water immersion

Heat stroke treatment method

Confusion, collapse, unconsciousness

Symptoms of heat stroke

False

T/F: All energy used for muscle work becomes mechanical output.

True

T/F: Heat production is proportional to O₂ consumption.

True

T/F: Heat stroke can be fatal if untreated.

False

T/F: Body temperature never exceeds 40°C in athletes.

True

T/F: Brain cells are sensitive to extreme heat.

>3% body weight loss

Main cause of performance drop from dehydration

Aldosterone

Hormone responsible for salt retention

Low NaCl loss

Effect of sweat gland acclimatization

Drinking hypotonic fluids

Main cause of exercise-associated hyponatremia

Brain edema

Result of excessive water intake with low salt

False

T/F: Athletes always benefit from salt tablets during exercise.

False

T/F: Sweating decreases potassium loss.

True

T/F: Aldosterone increases sodium reabsorption.

False

T/F: Acclimatized athletes lose more salt through sweat.

True

T/F: Hyponatremia is caused by drinking too much water with low sodium.

Caffeine

Drug linked to improved running time (inconsistent findings)

Androgens

Steroids that increase muscle mass and heart risk

Amphetamines

Substance that may interact dangerously with catecholamines

Hypertension

Potential cardiovascular side effect of steroids

Ventricular fibrillation

Consequence of stimulant overdose in sports

False

T/F: Caffeine consistently enhances performances in all athletes.

True

T/F: Steroid use may increase LDL and decrease HDL.

False

T/F: Cocaine boosts long-term athletic performance.

True

T/F: Amphetamine overuse can lead to cardiac arrest.

False

T/F: Androgens have no effect on cardiovascular health.

50-70 years old

Age group with 3× less mortality in fit individuals

Respiratory and cardiovascular

Key systems with increased reserve from fitness

Low LDL, High HDL

Effect of fitness on lipid profile

Type 2 cancer, diabetes, obesity

Diseases reduced by fitness

Pneumonia in elderly

Cardiac condition that benefits from increased reserve

True

T/F: Fitness lowers the risk of cardiovascular disease.

False

T/F: Increased fitness increases the risk for Type 2 diabetes.

True

T/F: Physical fitness improves recovery during illness.

False

T/F: Fitness has no effect on cancer risk.

True

T/F: Fit older adults have lower mortality.