Exercise Physiology Final Exam Study guide

What is the definition of obesity?

Excessive body fat that negatively affects health and increases disease risk.

What are the BMI categories and their values?

Underweight <18.5; Normal 18.5-24.9; Overweight 25-29.9; Obese ≥30.

What are the downsides of using BMI?

It does not distinguish fat vs muscle, has a weak relationship with fatness, and varies by age/sex/athletic population.

What is the 2-compartment model in body composition?

A model dividing the body into fat mass (FM) and fat-free mass (FFM).

What is the underlying principle needed for weight loss?

A negative energy balance (calories out > calories in).

What is conduction in thermoregulation?

Heat transfer through direct contact with an object.

What is convection in thermoregulation?

Heat transfer by the movement of air or liquid across the skin.

What is radiation in thermoregulation?

Transfer of heat via infrared rays without physical contact.

What is evaporation in thermoregulation?

Heat loss when sweat turns to vapor; the primary heat loss during exercise.

Which modes of heat transfer involve dry heat exchange?

Conduction, convection, radiation.

Which mode of heat transfer involves wet heat exchange?

Evaporation.

What factors affect the rate of evaporation?

Air movement, amount of exposed skin, temperature, and humidity.

What must occur with vapor pressure for evaporation to take place?

Skin vapor pressure must be greater than environmental vapor pressure.

What core temperature leads to nervous system dysfunction?

Above 40°C (104°F).

What physiological responses occur with heat acclimation?

Earlier sweating, more sweat, lower core temp, lower skin temp, lower HR, higher plasma volume, increased skin blood flow.

What is the role of the hypothalamus in thermoregulation?

Acts as the body's thermostat and maintains the temperature set point.

What do thermoreceptors do in the body?

Central receptors monitor blood temperature; peripheral receptors monitor environmental temperature.

What are the primary effectors that alter body temperature?

Sweat glands, arterioles, skeletal muscles, and endocrine glands.

What happens to the body when sweat rate increases?

Blood volume decreases, electrolytes are lost, dehydration increases, and aldosterone and ADH are released.

At what percentage of bodyweight loss does performance begin to decline?

At 2% bodyweight loss.

What adaptations to heat acclimation improve exercise capacity?

Earlier sweating, increased sweat rate, increased plasma volume, lower HR, lower temperatures, increased skin blood flow.

What stimulates aldosterone, and what is its function?

Stimulated by low blood pressure/volume; increases sodium reabsorption.

What stimulates ADH, and what is its function?

Stimulated by increased plasma concentration; increases water reabsorption.

What is the complement system made of and what does it do?

Proteins that bind bacteria, form membrane holes, and tag pathogens for destruction.

What components make up innate immunity?

Skin, mucosa, phagocytes, NK cells, and complement proteins.

What is the role of cytokines in the immune system?

They signal and coordinate immune responses and attract immune cells.

Which cells release cytokines?

Macrophages, neutrophils, and NK cells.

What is chemotaxis?

The movement of immune cells toward chemical signals at an infection site.

What are neutrophils and what do they do?

First-responder phagocytes that circulate in the blood.

What are monocytes and what do they do?

Blood cells that migrate into tissues and become macrophages.

What are macrophages and what is their role?

Tissue phagocytes that engulf pathogens and release cytokines.

What are Natural Killer Cells and what do they do?

Cells that kill infected or cancerous cells and release cytokines.

What are antibodies and what is their function?

Proteins from B cells that bind to specific antigens.

What are antigens?

Foreign substances that trigger an immune response.

What are cytokines?

Proteins that regulate immune communication and attract immune cells.

How does moderate-intensity exercise affect immunity?

It lowers URTI risk and increases NK cells, neutrophils, and antibodies.

How does high-intensity or long-duration exercise affect immunity?

It increases URTI risk, suppresses immune cells, raises cortisol, and creates an "open window" of vulnerability.

What factors increase infection risk in athletes?

High intensity training, long duration, stress, poor sleep, poor nutrition, and environmental stress.

Where is the chest skinfold site located?

A diagonal fold between the armpit and nipple (men: midpoint; women: 1/3 distance).

Where is the abdomen skinfold site located?

A vertical fold 2 cm to the right of the umbilicus.

Where is the thigh skinfold site located?

A vertical fold halfway between the hip and knee.

Where is the triceps skinfold site located?

A vertical fold midway between the acromion and elbow.

Where is the suprailiac skinfold site located?

A diagonal fold above the iliac crest.

Where is the midaxillary skinfold site located?

A vertical fold on the midaxillary line at the level of the xiphoid process.

Where is the subscapular skinfold site located?

A diagonal fold just below the inferior angle of the scapula.

What are concerns when exercising in hot and humid environments?

Reduced evaporation, overheating, dehydration, and hyperthermia.

What are concerns when exercising in hot and dry environments?

Rapid evaporation, high sweat loss, dehydration, and heat gain when air temp exceeds skin temp.

What is the J-shaped curve relating exercise to URTI risk?

Sedentary = average risk; moderate exercise = lower risk; high intensity = higher risk.

What is the formula for desired body weight?

FFM ÷ (1 − desired body fat percentage).