Provide an example of a sport athlete who, in the course of competing, uses all three major energy pathways. Describe the individual demands that elicit the use of the energy pathways, how long the body utilizes each pathway as its main energy source, and why the utilization of all three is necessary for the athlete to compete.

Phosphagen --- 10 to 30 seconds

Anaerobic --- 10 to 120 seconds

Aerobic --- more than 120 seconds

Explanation:

Phosphagen energy system last from 10 to 30 seconds, the anaerobic system provides energy for very hard efforts that lasts from 10 - 120 seconds and  aerobic system lasts longer than two minutes in duration. The utilization of all three energy pathways are necessary for the athlete to compete because athlete needs energy in huge amount which can't be fulfilled with the use of one energy pathway so the athlete needs and use all the pathways during exercise.

since you have not provided the options here i   am going to give you general overview about hormone.hormone are actually the part of endocrine system in our body and produced by the endocrine glands. the hormones act like a chemical messenger   within human body. once produce by the glands they   travel through the blood stream and reach at specific or target tissue and organs   which result in control of our body function. the hormones are specific in their work and work on only the targeted tissue or organ   . with the of hormone endocrine system regulate the heart rate , metabolism, our mood and   growth as well as the development and even the sleeping cycle etc. they actually are the messenger for body cell and organs .