My Golem have sturdy as an ability but it can still be knocked out with one hit!
Sturdy is well a move that makes so the user is protected from one hit KO's (And it didn't become attacked with a move that hits more times like Bone rush. What is wrong?
If you are playing Platinum, Sturdy works differently in Generations 3 and 4. All it does is prevent One-Hit-Knockout moves from working. All other moves work normally.
Only from Black/White onward, it allows you to survive with 1 HP.