We've all seen that guy at the gym training for hours, sometimes twice a day, and you wonder sometimes... does he live here ?
In this example I will use a dear friend of mine that has always trained the way he did, "Redggy Jupiter" so Redggy wakes up in the morning everyday at 7:00 am sharp get to his office finish his day at 1:00 pm and starts his first session of Crossfit followed by hot yoga, follow by another hour or two of isolation training, which is equivalent to about 5-6 hours of training 7 days a week, that being said, that's the definition of over training, killing yourself day in day out at the gym for months.
Obviously the question is: am I over training ?
I believe that 98% of the people that thinks they're over training their muscles they have an illusion of over training, I don't believe in training a muscle group once a week, let alone the 3-4 exercises per muscles, most of my training consist of a 5-6 sets of the same muscle group, your nutrition plays a big role on how the training reflects on your body that's 80% of the hard work, now lets answer your questions by some questions you can ask yourself to know if you're over training....
1- Do you wake up sluggish in the morning and you have to drag yourself out of bed to eat your breakfast ?
2- You barely start training at the gym and you're so tired that you can't continue ?
3- Are you weaker then usual ?
4- You're suddenly loosing weight fast ?
5- You're getting sick and injured more often ?
Those are the red flags of over training if you don't have any of these symptoms, I say man up and get your ass back to the gym.