The Front Plank is probably the most important exercise you can do for your core. Both the side plank and the front plank can be modified to assist those whose wrists hurt planking on your hand, by planking on the elbow. Do these exercises consistently and “Build your pillar of strength!”
Start by holding the front plank as long as you can without low-back pain. The abs should support this, not the back. Build up to one or two minutes. The side plank might be a little tougher, so start by holding for 15 seconds and build up to 30, 45 and finally 60 seconds.