Extreme Conditioning

Extreme Conditioning is a Tier 3 perk in Call of Duty 4: Modern Warfare, Call of Duty: World at War, Call of Duty: Black Ops (Nintendo DS), Call of Duty: Black Ops II and Call of Duty: Modern Warfare Remastered, and a Tier 1 perk in Call of Duty: Modern Warfare 3 that doubles the user's sprint time. This perk was replaced by Marathon in Call of Duty: Modern Warfare 2 and Call of Duty: Black Ops. Extreme Conditioning does not increase the sprinting speed of the player. As most games after Call of Duty: Ghosts allow infinite sprint by default, it rarely appears anymore.