Related: 4 Abs Exercises You Haven’t Tried
Challenging your balance is an easy way to engage the muscles of your core. Take a purposeful walk carrying a dumbbell in only one hand, and you'll see what we mean. You might be tempted to lean into the side that's carrying the dumbbell, but don't! Instead, fight the imbalance by using your ab muscles to stabilize the body and remain upright.
Related: Tone Your Abs on a Mat
Another great way to avoid monotony in your ab routine is to focus on compound movements that engage multiple muscle groups. For example, the overhead-dumbbell reverse-lunge exercise doesn't look like a typical ab move, but it builds core strength while also engaging the muscles of your legs and butt. It's effective and multi-tasking.
Click through for photos on how to perform all six expert-recommended exercises. Women's Health
Related: 10 Abs Exercises Better Than Crunches