As per observation the following is a symptom of overtraining that is D) All of the above as these includes the Insomnia , Oversleeping , Getting sick easily.
The symptoms is the cause or the way to determine diseases.
Insomnia , Oversleeping , Getting sick easily are all symptom of overtraining as when any athelete or person over works or achieves.
Thus it is well explain.
To learn more about overtraining refer to link :
https://brainly.com/question/2113527
