The aerobic system starts producing energy during prolonged periods of light to moderate exercise.

According to a source, the answer is said to be true.

Aerobic system exercise lengthens the goal and procedural healthy lifestyle to an extent. To ensure that your goals for exercising are achievable and safe, first go see a doctor to make sure that handle physical exercise.  Next step is to define what you want to achieve by exercising and by doing so, you would know type of exercises you need.  If you are a beginner, train under a certified instructor to ensure you are doing it right. Exercise at a level that you can do.  Do not over train for it will do your body more harm than good.  Make sure you eat properly and get enough sleep so that your body can recuperate from such strenuous activity.