Question

for how long can the aerobic system maintain a moderate level of physical activity?
○ a. 10 seconds to 2 minutes
○ b. 2 to 10 minutes
○ c. 10 to 20 minutes
○ d. more than 20 minutes

Explanation:

The aerobic energy system uses oxygen to produce energy and is efficient for sustained, moderate - intensity activity. It can support physical activity for more than 20 minutes as it relies on the body's ability to supply oxygen over an extended period, unlike anaerobic systems which are for short - burst or shorter - duration activities. Option a (10 seconds to 2 minutes) is typical of anaerobic lactic or alactic systems. Option b (2 to 10 minutes) is also more in the realm of anaerobic - aerobic transition or early aerobic with some anaerobic contribution. Option c (10 to 20 minutes) is still shorter than the typical sustained duration of the aerobic system. So the aerobic system can maintain moderate - level physical activity for more than 20 minutes.

Answer:

d. More than 20 minutes