Within the body lies rarely tapped reserves of awesome power and energy. Usually when dealing with energy work I see people focusing on the power of the mind and soul and ignoring the body except to strengthen it in regards to the previously mentioned works of energy. The closest is talk of qi and vital energy that flows through meridians in the body that line up with acupuncture points and nerve clusters.
The closest to what I speak is found in books that teach work with qi though I feel much is lost in translation of how to properly stimulate and utilize this energy within the body and instead it has become the casual energy manipulation with singular emphasis on the spiritual and non-physical aspects of the self.
Now rather than bore with theory and explanation I shall instead give the means to train and tap into this energy. This exercise is simple and can be quickly mastered and expanded upon. Hold your hand out and make a fist clenching as tightly as you possible can. Your muscles are set at their limit and fully engaged. Now release your fist. This energy is purely physical muscle energy and not the kind we are looking for but now instead slowly clench your fist gradually increasing the tension in your nerves without fully engaging the muscles so you never reach the climax of your grip. Practice this until you feel an almost electrical charge in your hand. Now tell your body to clench your fist but do not clench your fist, only engage in tensing the nerves and arousing them as though you were conducting a muscular action, this is purely nervous energy that is the bridge between the physical electric and magnetic energies of the body and the non-physical energies.
Once you have mastered the above with your hand extend it along your arm and in time your entire body creating that nervous energy without engaging the muscles in anything more but subtle comfortable tension. This energy you can learn to direct with your mind as you would in exercises dealing with standard energy manipulation except this is far more potent and limitless with the proper practice. This is the same energy aroused by potent practices such as the death posture in the firing of sigils and for those with talent in that field with that specific practice can attest to its potency.
Now whenever you would manipulate energy also tense your body in this fashion and direct the nervous energy along with the astral energies. It may seem obvious but this is rarely stated or practiced except by accident without proper focus on arousing the energy within the body. This is also the energy associated with kundalini when brought to an unrestrained tempest through the nervous system and plays an important role in the practice of magnetism in the context of mesmerism and healing.