|Fighting Style||Spec Style|
|Similar||Flying Swallow Barrage|
|Anime||Want Some More?|
|“||The Apnea Rush, an attack that far exceeds the anaerobic training practiced by the most finely-tuned athletes. Even runners who have practiced anaerobic training for years must still breathe while they run, and boxers, even those with the best conditioning, take quick breaths between jabs. They can't keep attacking without breathing, and it's those pauses for breath, those tiniest of gaps, that leave them open to a counterattack. However, in Spec's case, he can keep up an attack for five minutes without ever taking a breath. That's his Apnea Rush, a brutal barrage of blows that doesn't allow for any counterattack, and it doesn't stop until his opponent's body lies in a lifeless heap.||”|
– Narrator about the technique.
Apnea Rush (無呼吸打撃, Mukokyū Dageki) is Spec's fighting technique.
By controlling his breathing algorithm, Spec is capable of unleashing over a hundred punches and kicks within the span of a few seconds, which are so fast that counterattack is near impossible. This allows him to 'melt' walls, human bones, and even metal.
He is capable of holding his breath for five minutes while attacking so his barrage doesn't end until his opponent lies in a lifeless heap of flesh. Spec's ability to hold his breath for five minutes is an important part of this technique. In normal combat, the moment a fighter pauses to take a breath between attacks provides an opportunity for their opponent to counterattack. Apnea Rush doesn't have this weakness.
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. Hanayama's high pain tolerance is what allowed him to both survive and made him the first to counter it.
The technique, however, is not all-powerful, having a drawback to its use - once it is used, there is a recovery period where the user must take deep breaths to bring oxygen back into circulation throughout their body again - which a fighter could take advantage of if the initial rush did not defeat them.