>>149721159
Dragonball basically runs on xianxia cultivation rules, if your Ki is drained or your guard is down and you're not actively circulating it your body isn't much more durable than a regular person's unless you've done specific body-refining techniques or have naturally durable biology even untrained. Saiyans are strong but they don't have natural bullet proof skin or anything, meanwhile Frieza never worked out seriously in his life and is a freak mutant who can survive in space and atmospheric re-entry unaided so he'd likely be fine even if surprised