Fatigue
This is when the body of the individual or even their body part starts to feel sore or heavy. This might last for about three or more days. Individuals never are able to recover from the effort of the previous workout session.
Mood Swings Or Agitated Easily
Quite often levels of concentration decrease noticeably due to mood swings and agitation. Individuals begin to produce different hormones when they exercise. These hormones require rest periods so that they can return to normal levels. Over-training decreases the ability of the body to eliminate these hormones from the system. This could lead to imbalances within the body.
Reduced Appetite
Imbalances in hormones could often impact the appetites of individuals. This is at a time when the body really requires fuel for repair, the system shuts down and stops informing the individual of this. This is because of the imbalance of hormones being produced.

Injuries
Niggles and injuries could be a result of over-training. This might appear to be obvious; however, individuals often force themselves to push through small aches and pains. This is the time the body is trying to indicate that you need to slow down and probably take a break.
Under-Fueling
This is not an indicator of over-training; however, it is one of the most common reasons that result in it. This means that individuals are not providing their bodies adequate amounts or even the correct form of fuel. For the type of exercise or workout that the individual is expecting the body to perform, the fuel is not enough. This results in extreme under-performance while trying to train.