Run Speed Up
From Inkipedia, the Splatoon wiki
Run Speed Up increases movement speed in Inkling form by up to 50%. Rockenberg gear has a 5x chance of rolling this ability.
In-Depth Ability
This ability affects movement while running and while firing your weapon. However, it does not affect rolling speed with roller-type weapons, or jump length.
Use
This is one of the more effective abilities, particularly when rushing objectives like Splat Zones during the opening moments of a match.
Gear
Run Speed Up is the main ability of: