Overtraining syndrome only occurs in serious athletes who are training extensively.

The above is statement is true. It is true that over-training syndrome only occurs in serious athletes who are training extensively.

This condition occurs when the body is pushed beyond its natural ability to recover. it frequently occurs in athletes who are training for competition or a specific event and train beyond the body's ability to recover. The body would therefore require adequate rest and recovery to avoid a decrease in performance.

For the answer to the question above,

The answer is true.

Because their body and mind are conditioned and trained. They forgot fatigue and they push their body beyond its natural ability to recover. This may result in extreme fatigue. Muscle soreness, nausea, vomiting