The significance in thickness between the two is due to the different amount of pressure exerted on the walls of the heart. The left ventricle has a thicker wall because the blood must be pumped throughout the entire body (oxygenated blood), unlike the right ventricle, where blood is pumped simply to the lungs to be oxygenated (pulmonary system).
The great saphenous vein (or GSV).
Training too many times a week and not letting your body rest.
Ballistic stretching is not safe for the average person.
It is true because if you train to hard you are gonna get overload syndrome.