Questions for a new personal trainer

[PSeca]

I'm currently taking the NSCA course, and i'll be posting up questions i have every now and then.

Suffice to say ill be bumping this thread over the course of the next month with new questions.

My first one pertains to types of muscle

Type 1 muscle and Type 2 A / B muscle.

I know

Type 1 is a type of fiber that fights fatigue for an extended period of time

Type 2 A is an intermediate between anaerobic and aerobic exercise

Type 2 B is extremely good at anaerobic exercises

So my question is as follows.

if your a runner and start lifting are you converting muscle type 1 into muscle type 2 A? or creating completely new muscle fibers?

[Aoife]

Welcome.

While I don't know much in the area, I've seen plenty of talk that you don't really create new muscle fibers, or convert them. From what I understand, you simply work to improve the ones you have. You have all the fibres you'll ever have, without actually doing something to add/remove them. So if you start lifting, you'd simply start using the type of muscle fibres you already have, but haven't been using as much, thereby making them "better" and more useful than they were before.

[LisaS]

I'd suggest that you do a google search on muscle fiber types and you will find lots of information on if/when different types convert and what exactly that means (which depends on what was evaluated to type the muscle in the first place)

[AdamD]

Here are a couple of related threads:

muscle fiber proportions question

Q about muscle fibre and genetics.

The first one has a couple article links in it. Let me know what you think.