Hold a weighted implement such as a kettlebell, plate, sandbag, or medicine ball in both hands with the feet shoulder width or slightly wider. Rotate the trunk to hold the implement at the side of one hip to establish the starting position.
 
Rotate the trunk powerfully and swing the implement across your body and up above the shoulder opposite the starting hip. Return to the starting hip with speed but in control—emphasize the power of the movement up to the shoulder rather than back down to the hip.
 
Purpose
The cross chop trains rotational trunk strength to help overall trunk and hip control and stability.  
 
Programming
Cross chops should be done for sets of 10-30 reps per side.
 
Variations
Cross chops can be done with elastic bands or cable weight stack machines, but in these cases should generally be done with a more controlled tempo. With these, the resistance can also be reversed to pull down rather than up.