Marathon


 * For the Call of Duty 4: Modern Warfare challenge, see Boot Camp (challenges).

Marathon is a tier 1 perk in Call of Duty: Modern Warfare 2 and a Tier 3 perk in Call of Duty: Black Ops. In both games, it affects the player's sprint duration.

Call of Duty: Modern Warfare 2
Marathon gives the user an infinite sprint duration, replacing the Extreme Conditioning perk. It is one of the first perks in Create a Class, unlocked at the start of the game. The Pro version allows players to climb ladders and obstacles faster, making it useful if players are constantly being ambushed while climbing them.

Call of Duty: Black Ops
Marathon returns as a Tier 3 perk in Black Ops. As all perks, it costs and is available to be bought as soon as Create-A-Class is unlocked.

Overview
Marathon doubles the player's sprint duration, similar to Extreme Conditioning from Call of Duty 4: Modern Warfare and Call of Duty: World at War. Its Pro version gives the player unlimited sprint duration.

Pro Challenges

 * 26 Miles: Sprint 26 miles using Marathon.
 * First Blood: Get the First Blood medal 10 times.
 * Captures: In Capture the Flag, get the Flag Capture medal 15 times while using Marathon.

Miscellaneous

 * There is also a challenge in Call of Duty 4: Modern Warfare and Call of Duty: World at War called "Marathon," which is completed by sprinting 26 miles.

Call of Duty: Modern Warfare 2

 * To get the Pro version, the player must run 26 miles, the length of an actual Marathon.

Call of Duty: Black Ops

 * In Combat Training, the player does not need to complete the challenge "Captures" to achieve Marathon Pro since one cannot play objective-based gametypes in Combat Training.
 * The silhouette in the perk icon resembles an SOG Lightweight model. This could be a tip by players to use Lightweight in addition to Marathon, as Lightweight helps cover distances faster while being able to sprint for longer.