Which of the following is a sign to stop exercising immediately?

Loss of coordination is a significant indicator that one should stop exercising immediately. It suggests that the body is experiencing a disruption in its normal muscle function and nervous system communication, which can lead to an increased risk of injury. When coordination is compromised, it can affect balance and overall movement control, making it unsafe to continue any physical activity.

Maintaining a normal breathing pattern is expected during exercise; while changes are common, they should not signal a need to stop unless they become extreme. Increased endurance is a positive sign of improving fitness levels, indicating that the body is adapting well to exercise. Slight muscle fatigue, while it might be an indication of exertion, is generally a normal part of physical activity and not a reason to halt exercise unless it escalates to pain or severe discomfort.