Energy strikes were mentioned in the DVD #4 (Strikes, Punches and Kicks). Here, Vadim Starov goes much deeper. Famous Systema Wave pattern is used to obtain energy for a strike, different rotations are used to direct the energy to specific impact point (vital organs). DVD also covers how it will affect your opponent body. In my opinion, similar concept is used in Shaolin and Kung Fu. Great Systema Spetsnaz DVD to practice!