When we do weight lifting, with adequate protein intake, does it increase the number of muscle cells?

Question

or are we born with certain number of muscle cells (which means that number of muscle cells remain relatively constant throughout our life span) and we only increase the size of each muscle cells?


obviously when we do weight lifting, our arms become bigger, and I am curious whether it is that the number of muscle cells in that particular area (arms) increases, or it is that the size of each muscle cells get bigger (in this case, does the number of muscle cells remain constant?)!

Please explain to me in detail.

if you can explain in molecular level, how protein takes a role in this situation, that would be extremely helpful! Please explain what actually happens as we move the weights up and down, what happens to our orginal muscle cells, in detail, and how they tear up and recover, how in physiology our muscles are bigger in the end, in terms of how the muscle cell is different from the orginal muscle cell. Please explain in cellular, molecular and physiological level!thx:)

Answer 1

Hi. Finally a buddy from the gym :P
Well... Basically, both things happen when you workout and take those protein shakes. You increase muscle cell volume (the so called hypertrophy) but you also increase the total number of cells (called hyperplasia). Nevertheless, it is proven that most of the size comes actually from hypertrophy rather than from hyperplasia. You will find a lot of information here: www.bodybuilding.com

This is the best web site I ever visited in 6 years of BB.
And remember: "No pain. no gain" :)

Answer 2

The best reference i can give you is to go to HowStuffWorks.com and search for how muscles work, it will answer your question in detail and will help you understand exactly what you want to know.