Just like girls, during puberty, your body begins to grow faster. Some guys have uncomfortable growing pains in their arms and legs. How long this growth spurt lasts and how tall you'll be at the end of it depends on a lot of things â but mostly it has to do with how tall the other people in your family are.ow long this growth spurt lasts and how tall you will be at the end of it depends on a lot of things â but mostly it has to do with how tall the other people in your family are. During puberty, your breasts will change size and shape.
The pectorals are the two big chest muscles, and great pecs don't only look good, they are incredibly powerful. Focusing on this major muscle group 1-2 times a week is a big part of your workout routine, and it is easy to develop.
The pectoralis major has four actions which are primarily responsible for movement of the shoulder joint. The first action is flexion of the humerus, as in throwing a ball side-arm, and in lifting a child. Secondly, it adducts the humerus, as when flapping the arms.nderneath the pectoralis major is the pectoralis minor, a thin, triangular muscle. In sports as well as bodybuilding, the pectoral muscles may colloquially be referred to as  pecs .