Rack Out: Lunge with kettlebells in the front rack position and you’ll train your abs without even trying.

Down In Front

Lunging with weight held in front of the body rather than at the sides requires more work from your core to keep your torso upright. This is an important skill to train for protecting your lower back from injury. But since the move is still a lunge, and you’ll feel it mostly in your legs, you’re less apt to notice how hard your abs are working. Regardless, you won’t have to spend extra time training abs afterward.

How to 

1. Hold a kettlebell (or dumbbell) in each hand under your chin. Brace your abs and stand very straight.

2. Step backward and lower your body until your rear knee nearly touches the floor and your front thigh is parallel to the floor. Keep your torso upright. 

To prevent knee injury, your shin should always be vertical, with your knee over your ankle. 

SEE ALSO: Step Back For Size: Dumbbell Reverse Lunge