Tai Chi internal strength exercises were designed to do just that and build both a general type of tensile strength throughout the body while building up power generation in all key directions. Additionally the use of spiralling and coiling force is practiced leading to high levels of what the Chinese call Jin, well trained expression of force.
By doing this we can far more easily and effectively apply the techniques of the art, which may include various combinations of these more fundamental ways of using bodily power or Jin.
Tai Chi internal strength in practiced daily by advanced practitioners and will develop the muscular and fascial systems, loosen the joints making us faster, relax the whole body and also develop good balance and cardiovascular system.
There is a Yin method and a Yang method, each being practiced on alternating days, building a perfect balance between strength, power, stiffness, softness, relaxation and fluidity.