Ah, genetics. Science is such a wonderful thing, in that can show us how similar we are to apes and how we will never be Coleman no matter how hard we train. I've got a feeling what I'm going to say now will incite peer reviews till the cows come home, but referring to one's genetic limit is a scientifically proven excuse. There are a thousand and one ways you can environmentally manipulate the biochemical make up of muscle tissue and your body in general to maximise growth and strength. Your genetic makeup defines your individuality. If you want to lay the onus of blame on something, blame the world. That's what has really held you back. The relationship one's genetic makeup has to their adult (or teen) body is due to a series of chemical reactions that are dependant on an infinite amount of environmental factors.
For instance, breast-feeding. The longer you were breast fed as a baby, the more likely you are to develop a heavier build later in life, as important hormones are triggered and the level of food consumption is often set at that young age. Of course, this is not the only factor that will determine how you turn out as an adult. A lack or abundance of nutrients, or a changed dietary pattern caused by anything from onset of diabetes or a change in your geographical orientation will determine what your body has to work with, and what it has to do without. Hollywood has convinced us that the genes make the man, when really the genes are just an overview, or an infrastructure if you like. But once your body is developed, it becomes a great effort to manipulate and mould it into the shape you desire. That's why it's best to get in early, eat healthy and give yourself the best chance possible. To combat the cumulative effects of the environment you have to drastically alter your diet and exercising patterns, but essentially there is not much you can do. For the teens, I'd suggest eating three big healthy meals a day, drinking enough water and heaps of milk. Play a fitness intensive sport and make sure you are always chock full of vitamins. Don't blame your genes; they are only there to help you. I have gone on a bit here, but this is something I feel very strongly about.
There are some good articles on overtraining on Bb.com, like "Overtraining" by Russel Warren, but the main problem with fearing overtraining is under training, or not reaching ones best potential workout. Do not fear overtraining, although it is a very real problem, it is no way as big and evil as everyone makes it out to be. If you are really scared of overtraining then keep the reps high and the sets low, but essentially you cannot really overtrain a muscle in one workout. The best way to avoid real overtraining is simply stretching out your program over the week, and secondly listening to your body and not forcing it do something it obviously does not want to do. What I mean by this is do not train a sore muscle. There is a difference between sore and pumped.
TEN BY THREE
The ten by three rule is an interesting one that has popped up somewhere along the course of bodybuilding. Lifting a weight ten times then repeating the exercise three times is by no means the golden rule of growth. This is generally what beginners trust and adhere to. For a beginner who has no idea where to start, or what his muscles would best respond to, I suggest twelve to fourteen reps of light weights. I'm a big believer in the train to fail technique, and if you are like me then you will have goals for each individual set. Others have found that one set with a very light weight, and doing up to one hundred reps provides massive gains. The best way to overcome the ten by three dogma is to experiment. I recommend starting at twelve to fourteen reps and working around that. You try very high reps, very low reps, or whatever. Just do not set a limit. Limits are what bind you to mediocrity.
The fixed program is great to help you study what is working and what is not, but adhering to a set program can result in lack of creativity and the natural look of your muscles. Sometimes our body speaks to us without us really knowing and we listen to our head instead. I'm talked about boredom here. When a program gets repetitious and mundane that is the sign to change. To go against this because you tell yourself that you have to stick to it and be tough, though it may seem like the proper thing to do, it will put you in danger of throwing in the towel and putting your muscles in a stagnant stale mate. An example of having some variance in your workout is using the Pec Deck instead of flyes, or shrugging with dumbbells instead of a barbell. You can workout the same muscle the same way with a wide range of exercises. Be creative.
Finally, I would just like to add one of the biggest problems with teen bodybuilding is the over-reliance upon supplements due to beliefs that taking them will open a door to unlimited muscle growth. Quite frankly, this is idiotic. There is no gain without work.
Now get back to work,