A fun, new way to strengthen and stretch your core is to add a small kettle bell to your workout. This move is harder than it looks -- so don't be surprised if you can twist with only a small range of motion in the beginning. Your strength and flexibility will increase with practice.

1 Stand upright, with your feet together, holding one kettle bell in front of your chest with both hands. Lift your elbows out to the sides at shoulder height, palms facing your chest. Imagine pulling the handle of the kettle bell apart to help broaden your upper body.

2 Without twisting your hips, inhale and rotate your rib cage, shoulders and head to the left as far as you can. Make sure your elbows are still at shoulder height. Exhale and pause in the twist for two seconds. Rotate back to the center, inhale and twist to the right, exhale and pause for two seconds. Continue to alternate sides until you have done 15 twists on each side.

This article originally appeared in the Los Angeles Times in the "Good Form" feature of the Health Section. "Good Form" is updated with a new Karen Voight article each Monday.