What do the obliques do?
The internal and external obliques sit at the sides of the waist, running diagonally between the ribs and the pelvis. They twist and bend the trunk to the side, and they resist those movements when something tries to pull you off balance.
How do you train your obliques?
Side planks and carries with a weight in one hand train the obliques to stop you leaning. Anti-rotation exercises, like the Pallof press, train them to stop you twisting. Both carry over well to everyday tasks like carrying a bag on one side.