Overtraining is something that coaches and athletes have been worried about for years: push your athlete/client too hard for too long, and their performance will drop. The state of being overtrained manifests itself as fatigue, a lack of interest in training and diminished performance in the gym and on the field.
The current thought is that overtraining and overreaching (the former being long-term, the latter is short-term) are a neuroendocrine response to an imbalance between training, recovery and non-training related stressors (i.e. women and all the problems that come with them. I'm not jaded, don't worry). The neuroendocrine system controls the release of peptides, hormones and neuroamines. Hormones, as we know, are extremely important for many things.
What is the importance of overtraining? If you're an athlete or coach, it's what you want to avoid more than anything else. It produces a drop in performance both in the weight room and on the field of play, both of which are suboptimal scenarios. It will also cause the coach to have to put training on hold, which will result in a lower baseline level of performance when the athlete returns to the gym.
As a personal trainer, some of my clients who are a little more educated in the ways of training have been concerned about the possibility of overtraining. How real of a possibility is overtraining? For gen pop clients or for athletes? Let's discuss.
I believe that overtraining is a real thing, but is pretty rare. The imbalance between training and recovery will need to be pretty significant in order to create this actual state of being overtrained. The saying that has been floating around the strength and conditioning world is that "there's no such thing as overtraining, just under-eating."
While this isn't exactly 100% true, I think it's pretty close. You don't actually get stronger in the gym, you get stronger when you recover. Too many athletes and clients spend all their time focusing on what is happening in the gym rather then focusing on what happens when they go home. Recovery begins as soon as your training session is finished. If you finish your training, and then just go home and continue your day you're missing out. The first thing you need to be concerned about is feeding your body with the things it needs: protein and carbs. You have a 30-45 minute window post-training when your body is starving for nutrients and will partition them out to the places it needs them the most. This is the idea behind bringing your post-workout shake with you to the gym. Please make sure, though, that you have some quality protein if this is the road you're going to travel. Cut the bullshit with Muscle Milk and the nasty weight-gainers; those are just filled with sugar, fat and nasty chemicals. Spend the dough and buy a higher quality protein from a reputable company like BioTest, Optimum Nutrition or Stronger, Faster, Healthier.
The next step in recovery, and arguably the most important, is to get some sleep!! This is when your body actually performs all of its recovery processes, so when you cut sleep short you cut out a really important step in the recovery plan. 5 hours of sleep doesn't count, if you really want to recover. Especially for athletes. For general population clients, you're not doing yourself any favors if you're out boozing till 1 a.m. after a tough training session and don't go to bed until 2:30 in the morning.
Not getting enough sleep is a two-fold problem. The first is that you cut short your recovery time, the second is that if you don't get enough sleep you're going to feel like dogshit during your training session. I think some of my clients (you know who you are) are more than well aware enough of how you feel during a Saturday morning training session after a late night of beers.
So, can you overtrain? I think so. With that being said, it takes a lot more work than most civilians are capable of putting in. The more likely scenario is that you are under-recovering. One of my clients, a guy who see's me four times per week, read a few articles on T-Nation and was suddenly very worried about the possibility of overtraining. I had to lay it out for him that he really didn't work hard enough to overtrain, and that if he was feeling tired and run-down it's because he doesn't get enough rest. We do a deload every fourth week, and he never trains three days in a row. If you're sleeping enough and getting enough food then you will be juuuust fine. I promise.
One of the main reasons I'm so confident of this? The abundance of people who have no idea what overtraining is and never achieve it. How many guys in prison do you think know what overtraining is? My guess is very few. There are lots of strong guys in prison who just go as hard as they can every day, with little respect for the "laws" of strength and conditioning as we know them. They train, they eat whatever they can, and then they sleep a shit-ton. Thats about it. The other population that doesn't know about overtraining? The CrossFit community. I've read a lot of their literature, and there is very little (if any) talk about overtraining and deloads. Say what you will about the reasoning behind this, but there are some seriously beastly CrossFit athletes who haven't had a "deload" in quite some time. They train hard, and they eat the right food.
Go lift something heavy...then take a nap afterwards!