My point is that you can't grow new fibers period. All you can do is make the ones you were born with bigger.

Remember to never isolate yourself on working just the arms. The best thing to do is work your whole body. And in your case that would be a good thing. No point in having arms 3 times the size of your back or legs. That would be very disproportinate.

But you can grow new fibres, although that growth is - as I have already said - minimal in comparison to the overall increase in volume. Bottom line is, it is possible to add mass to the fibres, but you're not going to grow a bundle of fibres out of nowhere, that's for sure.

Also, if you were unable to grow new fibres, how do you expect damaged tissue to repair itself? For instance when a muscle snaps in half, it needs to grow new fibres and repair the damaged ones.

gaming, are you still in high school? If you are I suggest joining the swim team if they have one, if not then just go to a local pool and swim laps. That is an excellent way to get in shape and the advantage of swimming is that it works your entire body at once. You get a great deal of tone from doing a lot of swimming and if you train for sprinting you will get some rather large shoulders and legs in no time flat.

I think we're stuck on this because of a lack of a better term to coin muscle growing to repair damage and the growth of a bundle of new fibers. This website explicates better, and I'm sure we can reach a consensus.

http://umanitoba.fitdv.com/new/artic....html?artid=23

Each muscle comes with a certain number of fibers. This number can never be increased. The fibers can repair themselves, and they can grow bigger, but you can never grow more of them, just like you can't grow more neurons.

I wasn't saying that you could grow brand new ones, but if someone is able to increase his weight with 5kgs of muscle mass and the growth of muscles is largely dependant on the volumous increase, then we're overlooking something. If you increase the volume, you still need to increase the mass as well. So, although it's barely noticable, the fibres can increase their mass, but I believe the volumous increase is the most substantial - there's no doubt about this.

A correction is at hand.

I should've mentioned that yes, you do need to rest after exerting yourself so much, until you can feel no soreness at all. I don't actually think "kicking them when they're down" by doing lighter exercises on already sore muscles is necessarily a good idea, but as long as you know you're not just impeding their recovery I guess it's OK. I guess my point about training to failure was simply that if you only work within the limits of your body, your body won't have the stimulus to change. It would also help to regularly change the types of exercises you do, as someone mentioned, to avoid the risk of your body getting used to a pattern.

I don't care much for the more technical aspects of growth, but it can be observed by anyone that a person's physique will change to adapt to their environment. If your daily routine involves doing a lot of heavy work, you'll grow stronger (and a bit bigger) to cope. Good old-fashioned hard labour would be a perfect workout, yard work maybe.

I would prefer personally to be strong rather than huge, and to be strong you need core strength in vital groups, you can't strengthen just one particular set of muscles and expect to be strong; all that will happen is that the weaker of your muscles will fail when stressed by the stronger ones and let you down. So I agree with what Killy said earlier. Grip strength is a classic example of this; you could probably do a lot more pull-ups using those huge biceps if you could only hold on to the bar a bit longer.