Apnea Rush (無呼吸打撃, Mu Kokyū Dageki) is Spec's fighting technique.
By controlling his breathing algorithm, Spec is capable of unleashing over a hundred punches within the span of a few seconds, which are so fast that counterattack is near impossible. This allows him to 'melt' walls, metal and even human bones.
He used it during his fight against Kaoru Hanayama in the second series of the manga. The strength of his punches and kicks are enough to damage the Statue of Liberty.