Energy Systems & Exercise Physiology Flashcards

In exercise physiology, the Fick equation is used to calculate:

Answer: Oxygen consumption (VO2)

The Fick equation states that VO2 equals cardiac output multiplied by the arteriovenous oxygen difference, linking cardiovascular and muscular oxygen extraction.

Zone 2 (low-intensity aerobic) training in an indoor cycling class primarily relies on which energy system?

Answer: Oxidative system using fat as the primary fuel

Zone 2 corresponds to low-intensity aerobic exercise where the oxidative system, burning predominantly fat, supplies the majority of ATP.

How does exercising at altitude primarily affect aerobic performance?

Answer: It reduces oxygen partial pressure, decreasing aerobic capacity

At altitude, lower atmospheric pressure reduces oxygen partial pressure, limiting oxygen delivery to working muscles and impairing aerobic performance.

The phosphocreatine (PCr) energy system can sustain maximal effort for approximately:

Answer: 8–10 seconds

Phosphocreatine stores in the muscle are depleted within approximately 8–10 seconds of all-out maximal effort.

Which hormone plays the most critical role in preventing blood glucose from dropping too low during prolonged cycling exercise?

Answer: Glucagon

Glucagon is released by the pancreas when blood glucose falls, stimulating the liver to break down glycogen and release glucose into the bloodstream.

Mitochondrial biogenesis, a key adaptation to endurance training, refers to:

Answer: The creation of new mitochondria within muscle cells

Mitochondrial biogenesis is the process by which cells generate new mitochondria in response to endurance training, increasing the muscle's aerobic energy production capacity.

Even mild dehydration of 2% body weight loss during exercise can:

Answer: Impair both aerobic performance and cognitive function

A 2% body weight loss from dehydration reduces plasma volume and cardiac output, measurably impairing aerobic performance and cognitive function in exercising individuals.