Luffy’s Second Gear is probably one of the most popular moves within One Piece. That’s why I’m going to try to explain this special move to you guys who are unknown to what happens in the background when Luffy’s actually using it. I’ve collect these pieces of information for trusted local website. I have tweaked a few things to bring them up to date after the time skip.

Second Gear involves Luffy speeding up the blood flow in all or selected body parts, to give them more oxygen, ATP and other nutrients thus making him much faster and stronger. The technique uses even more oxygen and energy, using up more food and causing Luffy to pant heavily during his fights.

Doping is adding more red blood cells to the body part/s, which in turn allows for greater delivery of oxygen and nutrients to the body part/s. In Luffy’s case, his organs and blood vessels are made of rubber allowing them to expand and contract at greater rates without tearing. Essentially Luffy increases the blood flow by forcing more blood through his blood vessels thus increase his fighting ability. This mode’s enhancements to Luffy’s physiology give him the ability to use a new, stronger set of techniques which are generally the same as his old ones, but are so fast that even a skilled assassin would have a hard time actually seeing them.

After the time skip, it seems that Luffy has gained far greater control over this technique as he was shown to be capable of activating it by pumping blood in only one particular part of his body; the trigger works very fast as he is capable of activating Gear Second in an instant and doesn’t even have to assume his usual stance to start it. Thanks to his new-found control of this technique, Luffy now has the ability to select which body parts Gear Second will be active in instead of having to activate it in his entire body; the anime depicts this as the particular part undergoing the pumping motion, such as his arm.

To do any actions with Gear Second, Luffy will now start Gear Second in the part of his body he wishes to use and deactivates it once he has accomplished the task. Thus Luffy uses Gear Second for his usual fighting without using it on his entire body. Although the anime still has his entire body undergoing Gear Second’s effects, it still only lasts very short periods.

Here’s a list of the moves which Luffy uses during the anime and manga:
Gomu Gomu no Jet Pistol
Gomu Gomu no Jet Stamp
Gomu Gomu no Jet Bazooka
Gomu Gomu no Jet Whip
Gomu Gomu no Jet Bullet
Gomu Gomu no Twin Jet Pistol
Gomu Gomu no Jet Gatling
Gomu Gomu no Jet Rocket
Gomu Gomu no Jet Migawari
Gomu Gomu no Jet Rifle
Gomu Gomu no Jet Lance
Gomu Gomu no Jet Yari
Gomu Gomu no Jet Missile
Gomu Gomu no Jet Axe
Gomu Gomu no Jet Hammer
Gomu Gomu no Red Hawk

Thanks for reading! Hopefully you’ve learnt something new! Let’s thanks out source: OnePiece.Wikia.com!