Looking for a single great move towards achieving those wash-board abs? Well, this just may be the key! Warm up and give this abdominal exercise a try: standing weighted twist.
Stand with legs about hip width apart, or slightly wider depending on your balance. Hold your arms in a bent position with hands holding a dumbbell, medicine ball or kettle bell, up towards your chest; in such a way as if you are about to begin a round of boxing, but with weights in your hands.
As you twist your torso and arms to the left, raise your left knee upwards and towards the right. Just as your knee comes up, slightly bend your torso towards the knee while squeezing the right side of your abdominal wall. Bring arms back to the center and lower your foot until it just barely hits the ground; briskly twist again to the left while raising your left knee upwards towards the right side of your body, crunching slightly towards the knee. Continue this for a count of 15 repetitions and then continue in the opposite direction for a count of 15 repetitions; that will count as one complete set. Perform 3-4 sets total.
Modification: Simply perform this sequence without weights while keeping fists up and elbows bent.