Sprint in "Call of Duty: Black Ops 6" can be divided into two types: normal sprint and tactical sprint. When sprinting, press the sprint input again to start the tactical sprint. While in this state, you move slightly faster, but your weapon's sprint-to-fire lag is significantly increased.
How to use Tactical Sprint better in Call of Duty 21 Black Ops 6
Black Ops 6 is the first Treyarch title to feature Tactical Sprint, although it is functionally identical to past titles. While sprinting, press the sprint input again to initiate a tactical sprint. In this state, you move slightly faster (~+1m/s), but the weapon's sprint-to-fire delay is significantly increased. In combat, do not engage in tactical sprinting if you can avoid it.
Unlike IW and Sledgehammer's works, tactical sprinting in Black Ops 6 is significantly less effective. You only get a slight speed boost while in tactical sprint mode, and the duration is relatively short unless you use the "Double Time" perk. You should only use tactical sprints to quickly build momentum or retreat. It's almost useless for 6 vs 6 multiplayer, but can be beneficial in Zombies mode and Warzone.