Rule 1 - Cardio is an achievement in SAS: Zombie Assault 3. It is awarded when the player unlocks the Fitness Skill (meaning, when they reach Rank 24). It awards 25 upon unlock.
Triva[]
- "Rule 1 - Cardio" is a reference to the 32 "Rules" of the movie Zombieland, of which the first "Rule" is "Cardio".