A plank is a very effective way to strengthen all of your core muscles, which will help you with many other exercises. Planks are also good for improving balance and spinal health because they provide an intense workout that strengthens the back while giving it more support than crunches alone can do. Many people think planks are about just holding yourself up on your elbows, but there's so much more! You should try doing some simple variations like putting one hand behind their head or raising arm straight out from body and look at how different this exercise feels compared to if someone did these same moves flat on their back. The best part: With only three sets per day (10 reps each), you'll be getting stronger quickly