How do you improve muscle weakness?

How long does it take to see improvement in upper body weight lifting?

What are some good ways to develop fast twitch muscle fiber? Anyone know?

How come after I stretch and I'm all stretched out the next day my muscles are all tight? Example: Yesterday I stretched my ...

I heard that when running, the most used muscle is your abdomnal??? is it true??

what are the major superficial muscle groups? what do they do? how do they work?

I have a try outs in like a week and I was wondering if anyone had any good ways that you can lose weight and gain muscle. I ...

Does squeezing your tummy muscles help tone up?

I have a few questions about muscles. Would bike riding and running gain lower leg muscles? And if not, what will ? And how l...

Are there protein pills,to make you gain muscle?

Is it possible to pull a muscle in your armpit? I was fixing my shower, and stretched a little too far. Now my armpit hurts i...