Is is unhealthy for a 9-year-old boy to bodybuild? For example, if a 9-year-old started weightlifting and strenously exercising in an attempt to make himself bigger.

Yes.

 

Children under 16 should not attempt to gain significant muscle mass.

It could cause long term damage.

could you explain why?

 

i know at the health club in town, they won't let you wieght lift unless you are at least 13.

It damages the growth plates of the bones.

 

Generic item on growth plate injuries:

http://healthlink.mcw.edu/article/926048658.html

 

Apparently there is still some controversy, but most agree that resistance strength training is OK, maximal weightlifting is not.

 

http://www.lsus.edu/weightlifting/Papers%20Presented2.htm

looks like someones been watching too many documentaries...

 

wasnt there a documentary on bbc about this kid who had some really well defined muscles

... there was yes... and i think it was more OVER defined muscles!

No it`s not good!

 

Coquina`s perfectly correct, Weight training is NOT good at developing ages, it`ll create bone problems.

that`s NOT to say that execise of the cardio-pulminary sort aren`t good though, they`re a great way to assist growth, and not all in the ways visible.

wasnt there a documentary on bbc about this kid who had some really well defined muscles

I think you may refer to Freakchild:

 

http://science.slashdot.org/article.pl?sid=04/06/24/1234250&tid=191&tid=14

Yes.

 

Children under 16 should not attempt to gain significant muscle mass.

tried to explain that to the PE teacher today but he didnt hear anything of it. he did try to disprove it with biology things so atleast that means PE teachers have atleast some depth about them...

Pure weightlifting is bad because of the stress being placed on the kids bones. Other forms of training (resistance training as someone else said) are good. That's why most kids play a lot of sport, and don't weightlight.

tried to explain that to the PE teacher today but he didnt hear anything of it. he did try to disprove it with biology things so atleast that means PE teachers have atleast some depth about them...

He does not have the right to cripple your development.

 

If he (or your school's faculty) won't listen, a more suitably-qualified adult like your family doctor most certainly will.

tried to explain that to the PE teacher today but he didnt hear anything of it. he did try to disprove it with biology things so atleast that means PE teachers have atleast some depth about them...

 

You can improve muscle mass by resistance and isometric exercises that don't put stress on the growth plates of the bones like weight lifting does.

 

One thing that really makes "pretty muscles" is swimming. They become shaped over their whole length rather than having the mass concentrated in the belly. You can also resistance train effectively by standing in a pool up to your chest with a couple of empty gallon milk jugs in your hands. You can use both sets of muscles - one to push the jugs down to your size, and the other to control how fast they rise to the surface.

 

The "water aerobics" and resistance exercises are recommended for people with arthritis who can't bear weight on their joints, so I'm sure they would be OK for young people. Now - I doubt seriously that I could convince my grandson to go play in a pool with two empty gallon milk jugs. It's certainly not as macho as lifting a 200# weight - but results count.

another way to picture it is like this.

 

Imagine you have a crane with a hydrolic pump that can lift 50 tons, and cable that can hold that 50 tons.

built on a structure only capable of holding 30 tons safely.

 

it`ll take some of the weight for a while, but eventualy the framework will compress and become distorted and liable to break.

 

it`s a simplistic picture for sure, but very apt!

Let's not forget the hormone craziness.

From what I've read...

 

Long bones grow at the physis, the growth plates, which are cartilaginous. Because they are cartilaginous they are a weak point and fracture easily. During the healing of certain fractures to the physis, ossification can occur that prevents later growth. Fractures to the physis occur across a range of sports that children participate in, including weight lifting. However, I couldn't find anything (that was empirical) that suggested that weight lifting was extraordinarily dangerous. The most important thing seems to be to avoid excessive repetition of individual exercises.

 

reference:

 

Lipp, EJ. Athletic physeal injury in children and adolescents. Orthopedic Nursing. Mar/Apr 1998. Vol.17, Iss. 2