Question

A marathon runner continues to run long distances using the energy provided by respiration while a person being chased by a dog gets a burst of energy by respiration.

• A. anaerobic
• B. external
• C. physical
• D. aerobic

Answer 1

Answer: (A), (D)

aerobic

Marathon runners rely on aerobic respiration because it provides a sustained energy release in the muscles required for running long distances. If anaerobic respiration occurs, it would quickly cause muscles to cramp up due to the formation of lactic acid. This means that the runner would not be able to run for long.
Anaerobic respiration is performed when a burst of energy is required for a short time. The muscles would not have enough oxygen to meet the requirements and so will rely on anaerobic respiration to meet the energy demand.