theres a lot of topic on abs about diet and etc , i just turned 16, diet is clean and i do cardio with weight training, i have a beach slim lean tone where you can see the muscle interior shown on my arms cause i have like no fat, i have a 6 pac and i been training hard for that last 2 but it's hard, for some reason it won't show, my parents say it's because i need to be older and my muscle will develope more as my age increases is that true?if it is damm