There are two issues here, training to much or too hard in one session and training too frequently without enough rest. Both are overtraining. It is important to note when you are doing this, because exercise is doing you more harm than good at this point. A good rule of thumb, if you get done with your workout and you feel worse than when you started, you did too much.If you are overly tired for hours after your workout you are doing too much. The typical signs of overtraining include:
• Decreased performance – this is one of the earliest signs that you are overtraining
• Fatigue
• Headaches
• Elevated morning pulse/ resting heart rate
• Losing interest in exercise
• Mood changes
• Delayed recovery time – persistent muscle soreness that lasts for hours or days after your workout
• If you are losing weight but increasing your body fat
• Decreased immune system, you start getting sick all the time

Too much exercise can lead to injuries, exhaustion, and depression. It can also cause lasting physical harm to you and your adrenal glands. So listen to your body, if it is telling you it is too tired to go any father or to work out today, you should listen to that inner voice.