|Appears in||Call of Duty: Black Ops|
- "Woah, ok, that was sour!"
- — Tank Dempsey
It has 2 effects, one which is the standard version of the perk Marathon from multiplayer, which gives the player twice the amount of sprint endurance. The other effect is similar to the perk Lightweight from multiplayer, but mechanics are different. Instead of the 7% speed increase from Lightweight, Stamin-Up makes the player's weapon lighter, allowing them to sprint at the same speed as they would with a lighter weapon such as a Pistol or the Ballistic Knife with a heavy weapon such as an HK21 or RPK. Therefore, Stamin-Up is much more useful when the player has a heavy weapon rather than a lighter weapon as the speed increase is almost unnoticeable with light weapons.
The perk costs 2000 points. It is most useful when the player will be running around the map as part of their strategy, or if they are in danger and being chased by a massive horde of zombies. Also, it is useful when attempting to defend more than one Perk-a-Cola machine during a space monkey round on Ascension. It also comes in handy if one is trying to avoid George A. Romero, or revive a downed teammate.
- Ascension - Located past the gates to the left of the upper spawn door. It is in the back of the alleyway past the door leading to the launch pad near the AK-74u and next to a spawn point of the Mystery Box on the left.
- Call of the Dead - Behind the lighthouse and inside an abandoned house.
- Shangri-La - Will spawn randomly in one of the rooms underground (changes spawn with PhD Flopper, Double Tap and Deadshot Daiquiri).
- Moon - In the second room of Tunnel 11, to the left of the Semtex.
- The perk's name is a play on words of 7-Up, the popular soda, and the word 'stamina'.
- According to the characters, Stamin-Up has a sour taste.
- Even though the perk machine says that it's available in multiple colors, such as purple, blue, red, orange, yellow, and green (coincidentally, all the colors of every other available perk before its release), the player can only receive the yellow colored drink.
- The shape for the Stamin-Up perk machine has looks similar to the removed perk machine Amm-O-Matic.
- According to Dempsey, Stamin-Up tastes like "lemon lime with a twist of gasoline."