The reason behind an ectomorph  Arm Up System small frame is a fast metabolism rate. This results in 2 things a short time for the body to break down and use the energy from the food leaving little to no fat being left behind to store and also the body natural way to turn towards breaking down muscle as a source of energy. This group are usually plagued by significantly less result in terms of weights and resistance training because the training would cause the metabolism to spike even higher and without the proper diet and consistency this will result in slimmer chance in gaining the much needed mass.

Mesomorph on the other hand are what most men would love to get naturally. Their ability to gain and lose weight just by changing their diet and exercise with a slight variation result in many becoming models and contact sports like rugby or weightlifting. Similarly the reason behind this ability lies in a normal metabolism rate which burns less readily than the ectomorph and thus do not really need to turn to muscle breakdown as a way to get energy to fuel the body. This group of people can usually keep the muscular results from the gym on for a significantly longer time if they abide by a generally healthy diet.