Targets the obliques for a tighter, stronger waist.
Bend straight to the side only, don't lean forward or back.
Holding a single dumbbell on one side turns the obliques on your opposite side into both the brakes and the engine: they lower the weight under control, then pull your torso back upright. It is lateral flexion under load, a plane most training completely ignores. Strong obliques carry over to everything that resists twisting and tipping, from heavy carries to squats.
No, that is the classic mistake. Two dumbbells balance each other out and your obliques get nothing. One weight on one side is what creates the resistance.
With sensible loads, obliques are slow to add real size, and stronger obliques mostly show up as a tighter, more athletic midsection. If you are worried, keep the weight moderate and the reps controlled rather than maxing them out.
You are drifting forward or backward instead of bending purely sideways. Imagine sliding between two panes of glass, dumbbell tracking straight down your leg, and shorten the range until it is clean.
