a sore muscle is suffering from micro tears. These muscle tears are caused when you lift weight that puts the muscle unders serious stress. When the tears get repaired, they are bigger and stronger and so a muscle grows....

you can get larger by training a muscles and this muscle recruits more muscle fibres converting from type 1 to 2 and so forth but you have a pre-defines number of fibres so you can reach a limit... then they just grow bigger...

As i have trained through the years i have always suffered from DOMS (delayed onset muscle soreness) which is the feeling of sore muscles...... and i have always grown......


so speaking from my past, i say that if your not sore - you havent caused hypertophy and so the muscle wont grow....