Effects of weight training at early age

Is there any evidence that weight/strength training at an early age increases your potential for building muscle mass later on in your life?

My body seems to respond much more rapidly to weight training than my brother’s body; my muscles also tend to be more defined than his even without training. He claims that this is due to the fact that I did extensive exercising even before puberty (what can i say, i was an odd kid who was miles from the nearest neighbor); I say its much more likely that I lucked out and got the “muscle genes” and he didnt. Although we look much alike, averages dictate that we only share 50% of our genes, so this seems like a reasonable explanation to me. I think things would be the same even if we had the same history.

Anyway, is there any evidence that early weight training somehow affects gene expression…setting in motion a series of events that leads to having a potential for greater muscle mass later on?

A pretty good article outlining the pros and cons of lifting at an early age.